129 pubblicazioni classificate nel seguente modo:

Model based quantification of salinization dynamics under changing hydrological conditions in the Volturno River (Italy) coastal aquifer
JOURNAL OF HYDROLOGY
Autore/i: Gaiolini, M.; Ofori, A.; Postacchini, M.; Mastrocicco, M.; Colombani, N.
Classificazione: 1 Contributo su Rivista
Abstract: This work presents a semi-coupled modelling approach to study salinization dynamics in the Volturno River coastal aquifer (Italy), distinguishing among different salinization mechanisms. The area is of particular interest, given its location in the Mediterranean region, a climate change hot-spot. A 1D HEC-RAS numerical model was built up and run for a decade (2010-2020) to quantify the areal extent and timing of salinization events due to seawater encroachment within the Volturno River mouth. The results were used as input in a 3D SEAWAT model that incorporated salinity variations on a monthly basis for the same period. The SEAWAT model was down-scaled from a large calibrated MODFLOW model of the whole Campania region. Both national and worldwide databases were used to constrain the models. The model was then compared with 9 high resolution vertical profiles of porewater salinity obtained using a continuous coring sediment sampler, providing good model performance indicators (R2 = 0.867, NSE = 0.808, and RMSE = 3.926 g/L). Results highlight an increasing groundwater salinization pattern due to intrusion from the Volturno riverbed. The classical mechanism of seawater wedge intrusion from the coastline was minimal, while large inland portions of the model domain were characterized by high salinity (up to 75 g/l) due to remnant paleo seawater trapped into peaty and silty-clay aquitards. This physically-based modelling approach could be replicated in any coastal porous aquifer (if hydrological and hydrogeological datasets are available) to identify and quantify the salinization mechanisms and to help water managers to implement tailored solutions in the most affected areas.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/344813

Assessing the effects of ENSO-induced climate variability on shallow coastal groundwater reserves of north Patagonia, Argentina
GROUNDWATER FOR SUSTAINABLE DEVELOPMENT
Autore/i: Gaiolini, Mattia; Acosta, Rosario; Carol, Eleonora; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista

Additional sources of salinity and heavy metals from plant residues of peaty horizons in the Po River lowland (Italy)
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Habakaramo Macumu, Patrick; Gaiolini, Mattia; Ofori, Abraham; Mastrocicco, Micòl; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista
Abstract: The Po River lowland (Italy) is suffering of soil and surface water salinization due to seepage of saline groundwater into drainage canals of agricultural lands. The main drivers are paleo-saline porewaters trapped in peaty and silty clay lenses, deposited in back barrier and lagoonal environments. To study this phenomenon, a 2-ha tile drained agricultural field, experiencing dramatic crop yield decrease in the last years, was selected. The field is located in a reclaimed area at approximately 3 m below sea level in the Ferrara province, 24 km from the Adriatic Sea. To delineate the salinity gradients, 10 high resolution vertical profiles of soil cores were collected with a manual auger corer and analysed in laboratory for EC, pH, grain size, organic matter content, major ions and trace elements. The composition of porewater's leaching fraction (LF) was gained via deionized water batch extraction with solid liquid ratio 1:5, while the plant available water (PAW) was obtained via microwave hot water extraction in three selected profiles. Linear correlation matrix, principal components analysis (PCA), LF and PAW depth profiles were employed to gain insights on the salinity sources. Stratigraphical cores were almost homogeneous with the most permeable layers constituted by peats. An average porewater salinity of 8.2 g/L with a downward increasing trend was found, with slight acidic pH and very high content of organic matter. PCA highlighted the strong connection among some trace elements (like As, Cd, Cr, Li, Pb, Se), NH4+ and the saline peaty horizons. The PAW salinity was up to two times the LF, highlighting that peaty aquitards are the major saline source in these reclaimed lands. A new salinizing mechanism was then postulated, since plant tissue fragments can store much more salts than the mineral fraction and can act as a long-term source of diffusion driven salinization, so far neglected
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/340413

Unravelling the salinity origins in the coastal aquifer/aquitard system of the Volturno River (Italy)
WATER RESEARCH
Autore/i: Colombani, Nicolò; Alessandrino, Luigi; Gaiolini, Mattia; Gervasio, Maria Pia; Ruberti, Daniela; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: To counteract the ongoing salinization of coastal aquifers, which poses a significant environmental and socioeconomic challenge to local communities, it is necessary to first understand the origin and mechanisms of this phenomenon. This study investigates the origins of salinity in the Volturno River lowland in Southern Italy and reveals that the primary source in the area is paleo-seawater entrapped within sediments that were subject to evapoconcentration processes. By systematically collecting sediment samples at variable depths and locations and extracting porewaters, a comprehensive understanding of the interplay between freshwater and saline water was gained, including complex patterns of vertical stratification of groundwater salinity. The study highlights the limitations of traditional methods that rely on salinity monitoring via integral depth sampling, particularly in capturing the vertical redox and salinity gradients characteristics of layered aquifer/aquitard systems. On the contrary, environmental tracers, like chloride and bromide, provide valuable insights into the sources of groundwater salinity, distinguishing between current seawater intrusion and other causes, such as paleoseawater and return flow from drained agricultural land. Results suggest that the majority of salinity does not originate from modern seawater intrusion or recent evaporation. Instead, it can be attributed to paleo-seawater affected by evapoconcentration processes. This study has broader implications for the sustainable management of coastal aquifers and the safeguarding of freshwater resources. While our findings are specific to the Volturno River coastal area, the methodologies and insights here presented can be reproduced in every coastal region facing similar salinity challenges.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/335915

Simulating the effects of retreating Urmia Lake and increased evapotranspiration rates on the nearby unconfined aquifer
GROUNDWATER FOR SUSTAINABLE DEVELOPMENT
Autore/i: Abdollahi, Zahra; Feizizadeh, Bakhtiar; Shokati, Behzad; Gaiolini, Mattia; Busico, Gianluigi; Mastrocicco, Micòl; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista
Abstract: The unsustainable management of water resources along with climate change impacts have led Urmia Lake to severely shrink since 1995. To quantify the groundwater losses in the surrounding area and to avoid the future worsening of a yet worrying scenario a numerical model is needed. For this purpose, a transient state MODFLOW model (2000-2016) has been calibrated and validated versus hydraulic heads. Good model performances were obtained, allowing to accurately estimate the groundwater budget. MODIS dataset was employed to set up the numerical model to identify temporal and spatial extent of evapotranspiration. Evapotranspiration turned out to play a massive contribution in groundwater outflow showing an increasing trend over time. Several scenarios, considering a different way to implement recharge and evapotranspiration in the modelling routine were assessed. The role of the spatialization of the evapotranspiration extinction depth was investigated by averaging remotely sensed heterogeneous datasets over the model domain. No significant differences in model performance indicators were found. Moreover, a model scenario without human groundwater exploitation and land use change was considered. The results slightly differ from the groundwater budget calculated by the validated model and thus indicating the climate change as the major driver of groundwater depletion in the study area. The implementation of such a model allowed for the assessment of the exchange between the lake and the unconfined aquifer, providing a robust foundation for future sustainable management.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/335913

Direct and Remote Sensing Monitoring of Plant Salinity Stress in a Coastal Back-Barrier Environment: Mediterranean Pine Forest Stress and Mortality as a Case Study
REMOTE SENSING
Autore/i: Alessandrino, Luigi; Giuditta, Elisabetta; Faugno, Salvatore; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: The increase in atmospheric and soil temperatures in recent decades has led to unfavorable conditions for plants in many Mediterranean coastal environments. A typical example can be found along the coast of the Campania region in Italy, within the "Volturno Licola Falciano Natural Reserve", where a pine forest suffered a dramatic loss of trees in 2021. New pines were planted in 2023 to replace the dead ones, with a larger tree layout and interspersed with Mediterranean bushes to replace the dead pine forest. A direct (in situ) monitoring program was planned to analyze the determinants of the pine salinity stress, coupled with Sentinel-2 L2A data; in particular, multispectral indices NDVI and NDMI were provided by the EU Copernicus service for plant status and water stress level information. Both the vadose zone and shallow groundwater were monitored with continuous logging probes. Vadose zone monitoring indicated that salinity peaked at a 30 cm soil depth, with values up to 1.9 g/L. These harsh conditions, combined with air temperatures reaching peaks of more than 40 degrees C, created severe difficulties for pine growth. The results of the shallow groundwater monitoring showed that the groundwater salinity was low (0.35-0.4 g/L) near the shoreline since the dune environment allowed rapid rainwater infiltration, preventing seawater intrusion. Meanwhile, salinity increased inland, reaching a peak at the end of the summer, with values up to 2.8 g/L. In November 2023, salts from storm-borne aerosols ("sea spray") deposited on the soil caused the sea-facing portion of the newly planted pines to dry out. Differently, the pioneer vegetation of the Mediterranean dunes, directly facing the sea, was not affected by the massive deposition of sea spray. The NDMI and NDVI data were useful in distinguishing the old pine trees suffering from increasing stress and final death but were not accurate in detecting the stress conditions of newly planted, still rather short pine trees because their spectral reflectance largely interfered with the adjacent shrub growth. The proposed coupling of direct and remote sensing monitoring was successful and could be applied to detect the main drivers of plant stress in many other Mediterranean coastal environments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/335914

Identification and quantification of nutrients sources in the Aspio watershed (Italy). Insight from geogenic mineralization and anthropogenic pressure
CATENA
Autore/i: Busico, G.; Fronzi, D.; Colombani, N.; Mastrocicco, M.; Tazioli, A.
Classificazione: 1 Contributo su Rivista
Abstract: An accurate evaluation of river water quality could be challenging due to the complex hydrological and anthropogenic processes which affect its nature. Reliable water quality data are mandatory to identify long-term trends and regional variability at the watershed scale. In this study, a combined approach using time series, regression, and multivariate statistical analysis along with SWAT modelling was applied to identify the relevant hydrogeochemical processes and the nutrients sources within the Aspio watershed (Ancona, Italy). The analysis detected different processes: i) the geogenic origin of Cl- and SO42-, ii) the heavy metals (Cu and Ni) and hydrocarbons pollution due to runoff from urban and industrial areas, and iii) the agricultural contribution of pesticides, nitrogen, and phosphorous. A SWAT model was implemented to quantify the nutrients load in the Aspio river. A calibration for streamflow, river sediment yield, and for nutrients load was obtained considering agricultural, urban, and wastewater treatment plant contributions. Agriculture and treated wastewater contributed to the overall nitrogen load only for 4% and 12% respectively, while the majority was due to leakage from urban sewage (84%). A scenario with only fertilizers’ load (excluding other sources) highlighted that nitrogen and phosphorous export from agricultural lands did not significatively impact the Aspio river. The spatial representation of runoff susceptibility also showed how the highest susceptibility for nitrogen and phosphorous loads is due to areas located close to urban settlements.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326014

Numerical Modelling of Groundwater Level and Salinity Evolution in a Low-Lying Coastal Area Under Intensive Agricultural Activity
WATER RESOURCES MANAGEMENT
Autore/i: Gaiolini, Mattia; Colombani, Nicolò; Chierici, Valeria; Montanari, Laura; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: The groundwater salinity changes of the coastal unconfined aquifer of the Po Delta (Italy) from 2010 to 2020 were assessed via a density-dependent numerical model implemented with SEAWAT 4.2. The temporal discretization was defined on a monthly basis, allowing for detailed analysis of the evolution of salinity stratification within the aquifer and of the vertical fluxes induced by the reclamation drainage network. The validated model was used to unravel surface-groundwater interaction fluxes and the long-term impacts induced by the ongoing climate change. The simulation highlighted that deeper layers experienced a salinity increase due to the presence of hyper saline low permeability lenses, while shallow layers experienced both increasing and decreasing salinization trends, depending on the temporal and areal distribution of local factors such as recharge and evapotranspiration, the connection between the shallow aquifer and the drainage network, and the presence of a seawater wedge along the coastline. The sensitivity analysis performed on the maximum plant salt uptake due to evapotranspiration revealed a slight variation in the accumulated salinity mass and concentration within the aquifer, resulting in a maximum error of less than 2% at the end of the simulation
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/340437

Geostatistical assessment of groundwater arsenic contamination in the Padana Plain
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Schiavo, Massimiliano; Giambastiani, Beatrice M. S.; Greggio, Nicolas; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Arsenic (As) in groundwater from natural and anthropogenic sources is one of the most common pollutants worldwide affecting people and ecosystems. A large dataset from >3600 wells is employed to spatially simulate the depth-averaged As concentration in phreatic and confined aquifers of the Padana Plain (Northern Italy). Results of in-depth geostatistical analysis via PCA and simulations within a Monte Carlo framework allow the understanding of the variability of As concentrations within the aquifers. The most probable As contaminated zones are located along the piedmont areas in the confined aquifers and in the lowland territories in the phreatic aquifers. The distribution of the As contaminated zones has been coupled with hydrogeological, geological, and geochemical information to unravel the sources and mechanisms of As release in groundwater. The reductive dissolution of Fe oxyhydroxides and organic matter mineralization under anoxic conditions resulted to be the major drivers of As release in groundwater. This phenomenon is less evident in phreatic aquifers, due to mixed oxic and reducing conditions. This large-scale study provides a probabilistic perspective on As contamination, e.g. quantifying the spatial probability of exceeding national regulatory limits, and to outline As major sources and drivers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/329434

Disentangling hydrodynamic drivers of the Southern Venice (Italy) coastal aquifer via frequency decomposition analysis: Insights, challenges, and limitations
JOURNAL OF HYDROLOGY. REGIONAL STUDIES
Autore/i: Gaiolini, Mattia; Rama, Fabrizio; Mastrocicco, Micòl; Cosma, Marta; Donnici, Sandra; Tosi, Luigi; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista
Abstract: Study region: Shallow coastal aquifer located in the southern part of the Venice lagoon (Italy). Study focus: This study aims to improve the understanding of coastal aquifers’ hydrodynamics by implementing systematic time-series analyses of data. A collection of non-intrinsically consistent time series from hydrological (surface water and groundwater) and meteo-mareographic monitoring networks was obtained from different institutions. Each signal was broken down through a frequency decomposition analysis, isolating the main driving forces to focus on phenomena that occur at different time and spatial scales. New hydrological insights for the region: Results highlighted that the aquifer is highly connected with the Venice lagoon, with a clear fluctuation of piezometric heads induced by tidal major constituents, decreasing landward. Besides, the effects exerted by reclamation canals and pumping stations were also determined and found to increase landward. Despite the relatively simple behaviour of piezometric heads, the groundwater salinity is influenced by additional local factors, like probe depth, wells’ screen length, and vertical salinity distribution along the aquifer. These findings suggested how to make use of limited and sparse data to enhance the conceptual model of coastal aquifer hydrodynamics, while highlighting the limitations of existing monitoring networks. This outcome justified the need for an intrinsically-consistent network of dedicated multi-level samplers to avoid intra-borehole mixing and reliably characterize the groundwater salinity distribution
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/340436

Model-Based Analysis of Arsenic Retention by Stimulated Iron Mineral Transformation under Coastal Aquifer Conditions
ACS ES&T WATER
Autore/i: Barron, Alyssa; Jamieson, James; Colombani, Nicolò; Bostick, Benjamin C.; Ortega-Tong, Pablo; Sbarbati, Chiara; Barbieri, Maurizio; Petitta, Marco; Prommer, Henning
Classificazione: 1 Contributo su Rivista
Abstract: A multitude of geochemical processes control the aqueous concentration and transport properties of trace metal contaminants such as arsenic (As) in groundwater environments. Effective As remediation, especially under reducing conditions, has remained a significant challenge. Fe(II) nitrate treatments are a promising option for As immobilization but require optimization to be most effective. Here, we develop a process-based numerical modeling framework to provide an in-depth understanding of the geochemical mechanisms controlling the response of As-contaminated sediments to Fe(II) nitrate treatment. The analyzed data sets included time series from two batch experiments (control vs treatment) and effluent concentrations from a flow-through column experiment. The reaction network incorporates a mixture of homogeneous and heterogeneous reactions affecting Fe redox chemistry. Modeling revealed that the precipitation of the Fe treatment caused a rapid pH decline, which then triggered multiple heterogeneous buffering processes. The model quantifies key processes for effective remediation, including the transfer of aqueous As to adsorbed As and the transformation of Fe minerals, which act as sorption hosts, from amorphous to more stable phases. The developed model provides the basis for predictions of the remedial benefits of Fe(II) nitrate treatments under varying geochemical and hydrogeological conditions, particularly in high-As coastal environments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/335912

Effects of Graphene on Soil Water-Retention Curve, van Genuchten Parameters, and Soil Pore Size Distribution—A Comparison with Traditional Soil Conditioners
WATER
Autore/i: Alessandrino, Luigi; Pavlakis, Christos; Colombani, Nicolò; Mastrocicco, Micòl; Aschonitis, Vassilis
Classificazione: 1 Contributo su Rivista
Abstract: Graphene waste has had enormous growth due to many industrial applications. Agriculture exploits waste through the circular economy, and graphene waste is thereby investigated in this study as a soil conditioner for improving the physical-hydraulic properties of soil. Experiments were performed on three differently textured soils amended with traditional soil conditioners (compost, biochar, and zeolites) and graphene. The conditioners were applied at two different doses of 10% and 5% dry weight (d.w.) for compost, biochar, and zeolites, and 1.0% and 0.5% d.w. for graphene. We compared (i) the major porosity classes related to water-retention characteristics (drainage, storage, and residual porosity), (ii) bulk density, and (iii) van Genuchten water-retention curve (WRC) characteristics. Graphene application caused the largest decrease in dry bulk density (?(b)), lowering the soil bulk density by about 25%. In fact, graphene had ?(b) of 0.01 g/cm(3). The effects of graphene were more intense in the finer soil. Compost and biochar showed similar effects, but of lower magnitude compared to those of graphene, with ?(b) of 0.7 and 0.28 g/cm(3), respectively. Although zeolites had ?(b) of 0.62 g/cm(3), they showed quite different behavior in increasing the mixtures' ?(b). Graphene and biochar showed the most pronounced effects in the clayey soil, where storage porosity showed a reduction of >30% compared to the control. For storage porosity, the graphene treatments did not show statistically significant differences compared to the control. The results show that, when the conditioner increased drainage porosity, there was a high probability of a concomitant reduction in storage porosity. This finding indicates that graphene use for improving soil aeration and drainage conditions is viable, especially in fine soils.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326723

Modeling stochastic saline groundwater occurrence in coastal aquifers
WATER RESEARCH
Autore/i: Schiavo, Massimiliano; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: The issue of freshwater salinization in coastal areas has grown in importance with the increase of the demand of groundwater supply and the more frequent droughts. However, the spatial patterns of salinity contamination are not easy to be understood, as well as their numerical modeling is subject to various kinds of uncertainty. This paper offers a robust, flexible, and reliable geostatistical methodology to provide a stochastic assessment of salinity distribution in alluvial coastal areas. The methodology is applied to a coastal aquifer in Campania (Italy), where 83 monitoring wells provided depth-averaged salinity data. A Monte Carlo (MC) framework was imple-mented to simulate depth-averaged groundwater salinity fields. Both MC stochastic fields and the mean across MC simulations enabled to the delineation of which areas are subject to high salinity. Then, a probabilistic approach was developed setting up salinity thresholds for agricultural use to delineate the areas with unsuitable groundwater for irrigation purposes. Furthermore, steady spatial patterns of saline wedge lengths were unveiled through uncertainty estimates of seawater ingression at the Volturno River mouth. The results were compared versus a calibrated numerical model with remarkable model fit (R2=0.96) and versus an analytical solution, obtaining similar wedge lengths. The results pointed out that the high groundwater salinities found inland (more than 2 km from the coastline) could be ascribed to trapped paleo-seawater rather than to actual seawater intrusion. In fact, the inland high salinities were in correspondence of thick peaty layers, which can store trapped saline waters because of their high porosity and low permeability. Furthermore, these results are consistent with the recognition of depositional environments and the position of ancient lagoon alluvial sediments, located in the same areas where are the highest (simulated) salinity fields. This robust probabilistic approach could be applied to similar alluvial coastal areas to understand spatial patterns of present salinization, to disentangle actual from paleo-seawater intrusion, and more in general to delineate zones with unsuitable salinity for irrigation purposes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326724

Modelling biogeochemical reactions triggered by graphene's addition in a fertilized calcareous sandy soil
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Alessandrino, Luigi; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Graphene production has dramatically increased in the last years and new ways to recycle this engineered material need to be investigated. To this purpose, a reactive model network was developed using PHREEQC-3 code to quantify the relevant biogeochemical reactions induced by graphene scraps' incorporation in a calcareous sandy soil. The numerical model was calibrated versus a complete dataset of column experiments in water saturated conditions using two different fertilizers, a synthetic NPK fertilizer and fertigation water produced in a wastewater treatment plant. Column experiments consisted of 50 cm columns filled with a mixture of graphene scraps (0.015 % dry weight) and soil in the first 10 cm, while the remaining 40 cm had only soil. The model performance was tested using classical statistical indices (R2, Modelling Efficiency, and Index of Agreement), resulting to be satisfactory. Besides, a simple sensitivity analysis via the perturbation of relevant parameters showed a low degree of uncertainty. The main outcome of this study was the quantification of the increased denitrification rate triggered by graphene incorporation into the soil. Moreover, graphene incorporation substantially increased soil CEC and DOC sorption capacity, demonstrating a good adsorption capacity for ammonium and organic compounds, thus decreasing nutrients leaching that represents a major concern related to agricultural practice. Indeed, Graphene incorporation increased by 40 % the CEC in the first 10 cm of the CSG_NPK column (2.50e- 02 mol/L) respect to the CS_NPK column (1.75e-02 mol/L) and increased it by 150 % in the first 10 cm of the CSG_FW column (2.50e-02 mol/L) in comparison with the CS_FW column 1.00e-02 (mol/L). pH fluctuations were most likely due to the precipitation of Ca5(PO4)3OH, indeed the consumption of H+ ions could have triggered the pH lowering during the experiment. These results could be relevant for future graphene applications as a soil improver or as suitable material to enhance soil bioremediation in order to include graphene in a circular economy loop.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326725

Salinity origin in the coastal aquifer of the Southern Venice lowland
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Alessandrino, Luigi; Gaiolini, Mattia; Cellone, Francisco Aldo; Colombani, Nicolò; Mastrocicco, Micòl; Cosma, Marta; Da Lio, Cristina; Donnici, Sandra; Tosi, Luigi
Classificazione: 1 Contributo su Rivista
Abstract: Groundwater salinization can be natural and anthropogenic in origin, although it often results from a combination of both, especially in low-lying coastal regions that are hydraulically controlled. This study proposes a method to assess the origin of salinity using environmental tracers in porewater, like Cl- and Br-, combined with depositional facies associations detected in sediment cores. Such integrated approach was tested in a target area south of the Venice Lagoon (Italy), where groundwater salinization is triggered by multiple mechanisms due to the complexity of the hydro-geomorphological environment. Batch tests were performed on sediment core samples from boreholes to quantify major anions and total inorganic N. Cl- and Br- porewater concentrations coupled with sedimentary facies association provided insights into the origin of groundwater salinity from a variety of sources, including past and present seawater intrusion, agricultural leaching, and evaporites. The strengths and limitations of the integrated approach are discussed to provide a pathway for improving water resource management and planning measures to prevent groundwater salinization in coastal areas.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/326726

Seawater intrusion assessment along the Volturno River (Italy) via numerical modeling and spectral analysis
JOURNAL OF HYDROLOGY
Autore/i: Gaiolini, M.; Colombani, N.; Mastrocicco, M.; Postacchini, M.
Classificazione: 1 Contributo su Rivista
Abstract: Surface and groundwater salinization are becoming a significant challenge to inland water quality, negatively affecting people and ecosystems in coastal areas. Even if rivers provide critical pathways for seawater intrusion, this salinization phenomenon has received relatively little attention compared to other salinization mechanisms. To assess the distribution of salinity along the final reach of the Volturno River (Italy), an entire hydrologic year was modeled using the HEC-RAS software. The model was fed with high resolution time-series measurements (time interval of 10 min) of water surface elevations at both river mouth and Cancello Arnone (a hydrometric station located 13 km inland). Field observations and remote sensed data were used to perform the hydrody-namic analysis. The model showed good performance indicators (R2 = 0.878, NSE = 0.870, and MAE = 0.037 m) and well caught hydrometric variation over the simulation period. The tidal component was affected by dissi-pation moving upstream and showed the capability to shape the salinity profile during dry periods. Whereas during wet periods, even if a strong tidal component is present, the profile is totally regulated by the river discharge. The analysis of the salinity distribution, modelled via the Water Quality module, revealed the massive contribution of the river discharge in limiting seawater intrusion. A correlation between intrusion events and hydrometric stages was established over twenty years (2002-2022), showing a consistent trend between intrusion occurrence and the surface water storage anomaly in the lower Volturno River calculated by Global Land Data Assimilation System (GLDAS) model. Although the 1D approach here used may lead to uncertainties in the reproduction of the involved hydrodynamic and salinization processes, the results are useful for the under-standing of seawater intrusion in rivers, and may be utilized to study seawater intrusion in aquifers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/325660

Performance of graphene and traditional soil improvers in limiting nutrients and heavy metals leaching from a sandy Calcisol
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Alessandrino, Luigi; Colombani, Nicolò; Aschonitis, Vassilis; Eusebi, Anna Laura; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Given the large amount of Graphene produced in the last years, there is the need to introduce this new material into a green and circular economy loop. In this study, for the first time, the fate of nutrients and heavy metals in a sandy Calcisol amended with Graphene was monitored and compared to other traditional improvers such as Compost, Zeo-lites, and Biochar. This was performed via saturated and unsaturated columns' experiments with two different fertili-zation regimes: one with NPK fertilizer and one with an innovative fertigation water (FW) produced from a pilot wastewater treatment plant. The breakthrough curves of each nutrient and heavy metal were analysed to understand the main processes occurring in saturated and unsaturated conditions, comparing the columns amended with the im-provers versus the unamended Controls. Mass balances for each nutrient and heavy metal were developed to infer whether the different soil improvers were effective in minimizing leaching. Graphene, for most cases, behaved as the Control in nutrients' leaching for all the saturated and unsaturated experiments, both with NPK and FW. Biochar increased EC, K+, and pH of the leaching water, which could be an issue for the growth of some plants. Compost in-creased NO3- leaching in all the experiments. Zeolites showed the best N compounds retention, but great PO4 3- leaching in saturated conditions. Heavy metals leachates were analysed only for unsaturated columns (as more repre-sentative of field conditions) and found at concentrations well below the limits suggested by the U.S. Environmental Protection Agency. Overall, Graphene performed well in minimizing nutrients and heavy metals leaching, respect to classical improvers. This study is a starting point for field studies that will be critical to have a clear understanding of how Graphene behaves in the environment.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/316914

Assessment of intrinsic aquifer vulnerability at continental scale through a critical application of the drastic framework: The case of South America
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Rama, F.; Busico, G.; Arumi, J. L.; Kazakis, N.; Colombani, N.; Marfella, L.; Hirata, R.; Kruse, E. E.; Sweeney, P.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: An assessment of the intrinsic aquifer vulnerability of South America is presented. The outcomes represent the potential sensitivity of natural aquifers to leaching of dissolved compounds from the land surface. The study, developed at continental scale but retaining regionally a high resolution, is based on a critical application of the DRASTIC method. The biggest challenge in performing such a study in South America was the scattered and irregular nature of environmental datasets. Accordingly, the most updated information on soil, land use, geology, hydrogeology, and climate at continental, national, and regional scale were selected from international and local databases. To avoid spatial discrepancy and inconsistency, data were integrated, harmonized, and accurately cross-checked, using local professional knowledge where information was missing. The method was applied in a GIS environment to allow spatial analysis of raw data along with the overlaying and rating of maps. The application of the DRASTIC method allows to classify South America into five vulnerability classes, from very low to very high, and shows an overall medium to low vulnerability at continental scale. The Amazon region, coastal aquifers, colluvial Andean valleys, and alluvial aquifers of main rivers were the areas classified as highly vulnerable. Moreover, countries with the largest areas with high aquifer vulnerability were those characterized by extended regions of rainforest. In addition, a single parameter sensitivity analysis showed depth to water table to be the most significant factor, while a cross-validation using existing vulnerability assessments and observed concentrations of compounds in groundwater confirmed the reliability of the proposed assessment, even at regional scale. Overall, although additional field surveys and detailed works at local level are needed to develop effective water management plans, the present DRASTIC map represents an essential common ground towards a more sustainable land-use and water management in the whole territory of South America.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298652

Differentiating Nitrate Origins and Fate in a Semi-Arid Basin (Tunisia) via Geostatistical Analyses and Groundwater Modelling
WATER
Autore/i: Ncibi, K; Mastrocicco, M; Colombani, N; Busico, G; Hadji, R; Hamed, Y; Shuhab, K
Classificazione: 1 Contributo su Rivista
Abstract: Despite efforts to protect the hydrosystems from increasing pollution, nitrate (NO3-) remains a major groundwater pollutant worldwide, and determining its origin is still crucial and challenging. To disentangle the origins and fate of high NO3- (>900 mg/L) in the Sidi Bouzid North basin (Tunisia), a numerical groundwater flow model (MODFLOW-2005) and an advective particle tracking (MODPATH) have been combined with geostatistical analyses on groundwater quality and hydrogeological characterization. Correlations between chemical elements and Principal Component Analysis (PCA) suggested that groundwater quality was primarily controlled by evaporite dissolution and subsequently driven by processes like dedolomitization and ion exchange. PCA indicated that NO3- origin is linked to anthropic (unconfined aquifer) and geogenic (semi-confined aquifer) sources. To suggest the geogenic origin of NO3- in the semi-confined aquifer, the multi-aquifer groundwater flow system and the forward and backward particle tracking was simulated. The observed and calculated hydraulic heads displayed a good correlation (R-2 of 0.93). The residence time of groundwater with high NO3- concentrations was more significant than the timespan during which chemical fertilizers were used, and urban settlements expansion began. This confirmed the natural origin of NO3- associated with pre-Triassic embankment landscapes and located on domed geomorphic surfaces with a gypsum, phosphate, or clay cover.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/314069

Special Issue "Salinization of Water Resources: Ongoing and Future Trends"
WATER
Autore/i: Colombani, N
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/314071

The origin of Uranium in groundwater of the eastern Halkidiki region, northern Greece
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Kazakis, N.; Busico, G.; Ntona, M. -M.; Philippou, K.; Kaprara, E.; Mitrakas, M.; Bannenberg, M.; Ioannidou, A.; Pashalidis, I.; Colombani, N.; Mastrocicco, M.; Voudouris, K.
Classificazione: 1 Contributo su Rivista
Abstract: Uranium (U) pollution in groundwater has become a serious problem worldwide. Even in low concentrations, U has both radiological and toxicological impacts on human health. In this study an integrated hydrogeological approach was applied to conceptualize an aquifer system, and determine the origin of U detected in the aquifer of the eastern Halkidiki region in northern Greece. Data from measurements of groundwater level and hydrochemical and stable isotope analyses of groundwater samples were applied to perform geochemical modeling and multivariate statistical analysis. The modeling and statistical analysis identified three hydrogeochemical groups within the studied hydro-system, and U(VI) as the dominant U species. The first group is linked to the deeper aquifer which is characterized by water-rock interactions with weathering products of granodiorite. In this group the dominant U species is uranyl phosphate and U concentration is 3.7 μg/L. The upper aquifer corresponds to the second hydrogeochemical group where U concentrations are mainly influenced by high concentrations of nitrogen species (NO3− and NO2−). Factor analysis further discriminated the upper aquifer into a saline coastal zone and an inland zone impacted by agricultural activities. The third hydrogeochemical group presents the highest concentration of U (up to 15 μg/L) in groundwater and corresponds to the internal aquifer system. The U within this system is triggered by the presence of Mn2+, while the long residence time of the groundwater contributes synergistically to the hydrogeochemical process. Manganese triggers U oxidation in parallel with Fe2+ precipitation that acts as a regulator of U concentration. Groundwater depletion of the upper aquifers promotes the up-coning of geothermal fluids from fault zones leading to increased concentrations of U in the mid-depth aquifers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298650

Soil Denitrification, the Missing Piece in the Puzzle of Nitrogen Budget in Lowland Agricultural Basins
ECOSYSTEMS
Autore/i: Soana, E.; Vincenzi, F.; Colombani, N.; Mastrocicco, M.; Fano, E. A.; Castaldelli, G.
Classificazione: 1 Contributo su Rivista
Abstract: Denitrification is a key process buffering the environmental impacts of agricultural nitrate loads but, at present, remains the least understood and poorly quantified sink in nitrogen budgets at the watershed scale. The present work deals with a comprehensive and detailed analysis of nitrogen sources and sinks in the Burana–Volano–Navigabile basin, the southernmost portion of the Po River valley (Northern Italy), an intensively cultivated (> 85% of basin surface) low-lying landscape. Agricultural census data, extensive monitoring of surface–groundwater interactions, and laboratory experiments targeting N fluxes and pools were combined to provide reliable estimates of soil denitrification at the basin scale. In the agricultural soils of the basin, nitrogen inputs exceeded outputs by nearly 40% (~ 80 kg N ha−1 year−1), but this condition of potential N excess did not translate into widespread nitrate pollution. The general scarcity of inorganic nitrogen species in groundwater and soils indicated limited leakage and storage. Multiple pieces of evidence supported that soil denitrification was the process that needed to be introduced in the budget to explain the fate of the missing nitrogen. Denitrification was likely boosted in the soils of the studied basin, prone to waterlogged conditions and consequently oxygen-limited, owing to peculiar features such as fine texture, low hydraulic conductivity, and shallow water table. The present study highlighted the substantial contribution of soil denitrification to balancing nitrogen inputs and outputs in agricultural lowland basins, a paramount ecosystem function preventing eutrophication phenomena.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298623

Variation of the hydraulic properties in sandy soils induced by the addition of graphene and classical soil improvers
JOURNAL OF HYDROLOGY
Autore/i: Alessandrino, L; Eusebi, Al; Aschonitis, V; Mastrocicco, M; Colombani, N
Classificazione: 1 Contributo su Rivista
Abstract: In this study, for the first time, the changes in relevant hydraulic parameters (e.g., hydraulic conductivity, effective porosity, and dispersivity) induced by the introduction of graphene in a calcareous sandy soil and a siliciclastic riverine soil were monitored and modelled via leaching column experiments. Column experiments were also run with traditional soil improvers (compost, biochar, and zeolite) to compare the changes induced by graphene versus well-studied soil improvers. Constant pressure head tests were used to calculate the hydraulic conductivity of each column, while leaching experiments were run to estimate porosity and specific retention, and for each treatment three replicates were done. Columns were then run in saturated conditions via a low flow peristaltic pump and monitored for electrical conductivity, temperature, and chloride. CXTFIT 2.0 was employed to inversely model the column experiments and retrieve parameters like effective porosity, longitudinal dispersivity, bulk thermal diffusivity, and thermal retardation factor. Results highlighted small changes of hydraulic conductivity, porosity, and effective porosity induced by graphene addition (as well as by the other soil improvers) for both soils. A marked increase (nearly 20 %) of specific retention values was instead recorded in the amended columns with respect to control ones. Chloride breakthrough curves modelling showed that graphene doubled dispersivity in the calcareous sandy soil (5.82 +/- 1.4 cm) compared to the control (2.6 +/- 0.29 cm), while it halved dispersivity in the siliciclastic riverine soil (0.31 +/- 0.05 cm) with respect to the control (0.65 +/- 0.06 cm). Thermal retardation factors were decreased by graphene by approximately 20 % for both soils. The model fitting via TDS (derived from the electrical conductivity monitoring) produced unreliable dispersivity values in most of the experiments due to the nonconservative nature of this parameter compared to chloride. The results highlight that graphene affected dispersivity but did not significantly alter other physical parameters relevant for solutes transport in sandy soils in comparison to classical improvers, thus future studies should focus on the graphene's effects on nutrients and agrochemicals leaching in unsaturated flow conditions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/314068

Testing graphene versus classical soil improvers in a sandy calcisol
CATENA
Autore/i: Alessandrino, L.; Colombani, N.; Eusebi, A. L.; Aschonitis, V.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: In this study for the first time, Graphene was tested in a leaching batch experiment on a calcareous sandy soil (Calcisol) to assess its capacity to ameliorate soil's properties in comparison with traditional soil improvers (Compost, Biochar, and Zeolites). A first set of experiments was performed in triplicates using the saturation soil extraction method (5:1 liquid–solid ratio) with deionized water as liquid phase and two different rates (minimum and maximum) of each improver. A second set of experiments (5:1 liquid–solid ratio) was performed to understand the fate of fertilizers, using the maximum amount of soil improvers and two different liquid phases: NPK solution from a synthetic fertilizer and fertigation water from a wastewater treatment plant. EC, pH, ORP and dissolved O2 were monitored daily for two weeks, and water samples were obtained at the end of the experiment to analyze DOC, major ions, and trace elements. Results showed that Graphene neither altered the physical–chemical parameters nor released nutrients and heavy metals in the solution in comparison to control and other improvers. Biochar increased EC and pH beyond recommended limits for some plants growth, while Compost released NO3– above threshold limits. Batches with the NPK solution showed NH4+ accumulation in the solute for controls, and to a less extent for Zeolites, Graphene and Biochar, while no accumulation was recorded for Compost. NH4+ accumulation was triggered by microbial N remineralization in absence of a C source. Batches with fertigation water showed NO2– accumulation in the solute due to incomplete nitrification in all the improvers and control batches, since the available C source consumed O2 that in turn hampered the nitrification process. Despite the above-mentioned limitations, Graphene performed well in comparison to the other soil improvers in reducing nutrients and metals leaching.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298621

Groundwater-surface water interaction revealed by meteorological trends and groundwater fluctuations on stream water level|Interazione acque sotterranee-acque superficiali rivelate dalle tendenze meteorologiche e dalle fluttuazioni delle acque sotterranee sul livello di un corso d’acqua
ACQUE SOTTERRANEE
Autore/i: Fronzi, D.; Gaiolini, M.; Mammoliti, E.; Colombani, N.; Palpacelli, S.; Marcellini, M.; Tazioli, A.
Classificazione: 1 Contributo su Rivista
Abstract: The importance of considering groundwater (GW) and surface water (SW) as a single resource of two interconnected components has rapidly increased during the last decades. To investigate GW-SW interaction in an aquifer system exploited by several pumping wells, an integrated continuous monitoring of the hydrological conditions was carried out. The sub-catchment (14 km2), located in the Aspio basin near Ancona (Central Italy), is drained by a small stream named Betelico, and it is characterised by the presence of an unconfined alluvial aquifer and a semi-confined limestone aquifer. The aim of this study is to evaluate the drivers of stream drying up occurred during the last couple of years. This has been achieved by applying a trend analysis on rainfall, air temperatures, piezometric and stream level, and well pumping rates. Precipitation trends were analysed over a 30-years period through the calculation of the Standard Precipitation Index (SPI) and through heavy rainfall events frequency plots, while the correlation between piezometric stream levels and pumping rate was analysed during the last six years. The groundwater level was compared with the stream baseflow level, highlighting the interconnection between GW-SW over the years. The analysis on the water surplus (WS) trend, together with the rainfall events characterisation, supports the hypothesis of the decrease in recharge rate as the main driver of the stream drying up. This case study stresses the importance of studying GW-SW interactions in a continuously changing climatic context characterised by a decreasing precipitation trend, coupling both the advantages of a robust method like trend analysis on time series and the field continuous monitoring.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/311972

Impact of Boundary Conditions Dynamics on Groundwater Budget in the Campania Region (Italy)
WATER
Autore/i: Gaiolini, Mattia; Colombani, Nicolò; Busico, Gianluigi; Rama, Fabrizio; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Groundwater budgets and fluxes are affected by human activities and climate change. Numerical models are cost-effective tools to investigate the different components of the hydrologic cycle. In this study, a groundwater flow model of the unconfined aquifers of the Campania region (Italy) has been developed and calibrated in Processing Modflow 11, resulting in an accurate assessment of groundwater fluxes and their trends over fifteen years (2000-2015). The model was implemented using a high-resolution grid to capture small hydrogeological features such as wells and rivers and informed by time variable datasets used as boundary conditions (i.e., river and sea levels, aquifer recharge, evapotranspiration, and discharge from adjacent systems). Good calibration and validation performances were achieved for piezometric heads (R-2 = 0.958). A set of scenarios was developed using constant boundary conditions (i.e., constant sea-level BC, uniform extinction depth BC), and the outputs were compared, quantitively assessing differences in groundwater fluxes. Simulations pointed out that using time series to inform boundary conditions in the model does not always result in a significant change in the computed fluxes. Overall, non-uniform extinction depth was the most influential condition, while both rivers and sea level conditions barely affected groundwater budgets. In addition, results highlighted the need for an accurate estimation of spatiotemporal variations of both recharge and evapotranspiration, due to their strong seasonal variability and their massive contribution to the hydrogeological cycle. Finally, a marked increase of evapotranspiration fluxes controlled by interannual variability of precipitation and atmospheric temperatures has been quantified over the modelled period.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/314070

In situ arsenic immobilisation for coastal aquifers using stimulated iron cycling: Lab-based viability assessment
APPLIED GEOCHEMISTRY
Autore/i: Barron, A.; Sun, J.; Passaretti, S.; Sbarbati, C.; Barbieri, M.; Colombani, N.; Jamieson, J.; Bostick, B. C.; Zheng, Y.; Mastrocicco, M.; Petitta, M.; Prommer, H.
Classificazione: 1 Contributo su Rivista
Abstract: Arsenic (As) is one of the most harmful and widespread groundwater contaminants globally. Besides the occurrence of geogenic As pollution, there is also a large number of sites that have been polluted by anthropogenic activities, with many of those requiring active remediation to reduce their environmental impact. Cost-effective remedial strategies are however still sorely needed. At the laboratory-scale in situ formation of magnetite through the joint addition of nitrate and Fe(II) has shown to be a promising new technique. However, its applicability under a wider range of environmental conditions still needs to be assessed. Here we use sediment and groundwater from a severely polluted coastal aquifer and explore the efficiency of nitrate-Fe(II) treatments in mitigating dissolved As concentrations. In selected experiments >99% of dissolved As was removed, compared to unamended controls, and maintained upon addition of lactate, a labile organic carbon source. Pre- and post-experimental characterisation of iron (Fe) mineral phases suggested a >90% loss of amorphous Fe oxides in favour of increased crystalline, recalcitrant oxide and sulfide phases. Magnetite formation did not occur via the nitrate-dependent oxidation of the amended Fe(II) as originally expected. Instead, magnetite is thought to have formed by the Fe(II)-catalysed transformation of pre-existing amorphous and crystalline Fe oxides. The extent of amorphous and crystalline Fe oxide transformation was then limited by the exhaustion of dissolved Fe(II). Elevated phosphate concentrations lowered the treatment efficacy, indicating joint removal of phosphate is necessary for maximum impact. The remedial efficiency was not impacted by varying salinities, thus rendering the tested approach a viable remediation method for coastal aquifers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298622

Natural and anthropogenic factors driving groundwater resources salinization for agriculture use in the Campania plains (Southern Italy)
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Mastrocicco, M.; Gervasio, M. P.; Busico, G.; Colombani, N.
Classificazione: 1 Contributo su Rivista
Abstract: The Mediterranean region is under pressure for a more sustainable use of water resources in view of the actual and future climate change. Under this pressure, the need to better assess the links between groundwater availability and quality and irrigated agriculture, is becoming urgent. Through the hydrogeologic and hydrochemical characterization of the coastal aquifers of a representative Mediterranean study area (the Campania Region in southern Italy), this study strengthened the analysis of basic components of the groundwater cycle and their temporal variability, including hydrologic, environmental and socio-economic aspects. Selected physiochemical properties of groundwater in 52 monitoring wells were considered from the Campania Environmental Protection Agency database. A total of 626 samples were collected from 2004 to 2018 to capture the water quality variability. Factor analysis and a specific groundwater quality index were also applied on 23 samples in two different timelines (2006, 2016) to capture the hydro-chemistry evolution through year. Moreover, land use and active pumping wells locations were used in the analysis. Spatial and temporal trends of base exchange indices (BEX) and sodium adsorption ratio (SAR) were computed along with Pearson coefficient among different variables, like well densities and distance from the coast. The variation in the distribution of salinity between 2006 and 2016, along with highly positive and highly negative BEX and groundwater quality index values, indicate unstable conditions for the future. In the greenhouse's areas, where groundwater exploitation is elevated, an increase of salinity was recorded due to seawater intrusion. In volcanic districts water rock interaction is the main driver of groundwater salinization, while mixing processes with carbonate freshwaters diminish groundwater salinities in the alluvial plains. This study demonstrates that groundwater over pumping can have a major impact on groundwater quality used for irrigation, despite the dominant influence that local geological and morphological features exert on the area.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286825

Nutrients and carbon fate in two lowland contrasting soils amended with compost
CATENA
Autore/i: Alessandrino, L.; Gervasio, M. P.; Vincenzi, F.; Colombani, N.; Castaldelli, G.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: The present study investigated the transient effects of compost application combined with minimum tillage followed by traditional fertilization in two contrasting agricultural soils of the Po River plain, where both nutrients leaching and carbon cycle were monitored for three years (2016–2019) via several campaigns of soil and groundwater sampling and gas emissions. The results of this work highlight that the effects of compost on nutrients leaching is transient and is soon lessened over time if new incorporations do not take place. Nutrients leaching was minimal on shallow groundwater quality with the following decreasing order: nitrate > ammonium > nitrite > phosphate. Moreover, the nutrients distribution profiles (nitrate, nitrite, ammonium and phosphate) also depended on the groundwater fluxes and on boundary conditions (geogenic sources and previous fertilizations). The soil organic carbon results highlight that its increase (approximately 1 ± 0.4% in both soils) was temporary and was not anymore discernible after three years since compost incorporation. The carbon dioxide emissions behave like the soil organic carbon, with an initial increase (approximately 66 ± 17 mM/m2/d in both soils) due to mineralization and a subsequent decrease, while no methane and hydrogen sulphide emission were detected. Moreover, carbon dioxide fluxes were also driven by the soil with nearly doubled fluxes in the site with a higher soil organic carbon baseline.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298620

Predictive modeling of selected trace elements in groundwater using hybrid algorithms of iterative classifier optimizer
JOURNAL OF CONTAMINANT HYDROLOGY
Autore/i: Khosravi, K.; Barzegar, R.; Golkarian, A.; Busico, G.; Cuoco, E.; Mastrocicco, M.; Colombani, N.; Tedesco, D.; Ntona, M. M.; Kazakis, N.
Classificazione: 1 Contributo su Rivista
Abstract: Trace element (TE) pollution in groundwater resources is one of the major concerns in both developing and developed countries as it can directly affect human health. Arsenic (As), Barium (Ba), and Rubidium (Rb) can be considered as TEs naturally present in groundwater due to water-rock interactions in Campania Plain (CP) aquifers, in South Italy. Their concentration could be predicted via some readily available input variables using an algorithm like the iterative classifier optimizer (ICO) for regression, and novel hybrid algorithms with additive regression (AR-ICO), attribute selected classifier (ASC-ICO) and bagging (BA-ICO). In this regard, 244 groundwater samples were collected from water wells within the CP and analyzed with respect to the electrical conductivity, pH, major ions and selected TEs. To develop the models, the available dataset was divided randomly into two subsets for model training (70% of the dataset) and evaluation (30% of the dataset), respectively. Based on the correlation coefficient (r), different input variables combinations were constructed to find the most effective one. Each model's performance was evaluated using common statistical and visual metrics. Results indicated that the prediction of As and Ba concentrations strongly depends on HCO3−, while Na+ is the most effective variable on Rb prediction. Also, the findings showed that the most powerful predictive models were those that used all the available input variables. According to models' performance evaluation metrics, the hybrid ASC-ICO outperformed other hybrid (BA- and AR-ICO) and standalone (ICO) algorithms to predict As and Ba concentrations, while both hybrid ASC- and BA-ICO models had higher accuracy and lower error than other algorithms for Rb prediction.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298615

Quantifying the impact of evapotranspiration at the aquifer scale via groundwater modelling and MODIS Data
WATER
Autore/i: Colombani, N.; Gaiolini, M.; Busico, G.; Postacchini, M.
Classificazione: 1 Contributo su Rivista
Abstract: In shallow alluvial aquifers characterized by coarse sediments, the evapotranspiration rates from groundwater are often not accounted for due to their low capillarity. Nevertheless, this assumption can lead to errors in the hydrogeological balance estimation. To quantify such impacts, a numerical flow model using MODFLOW was set up for the Tronto river alluvial aquifer (Italy). Different estimates of evapotranspiration rates were retrieved from the online Moderate Resolution Imaging Spectroradiometer (MODIS) database and used as input values. The numerical model was calibrated against piezometric heads collected in two snapshots (mid-January 2007 and mid-June 2007) in monitoring wells distributed along the whole alluvial aquifer. The model performance was excellent, with all the statistical parameters indicating very good agreement between calculated and observed heads. The model validation was performed using baseflow data of the Tronto river compared with the calculated aquifer-river exchanges in both of the simulated periods. Then, a series of numerical scenarios indicated that, although the model performance did not vary appreciably regardless of whether it included evapotranspiration from groundwater, the aquifer-river exchanges were influenced significantly. This study showed that evapotranspiration from shallow groundwater accounts for up to 21% of the hydrogeological balance at the aquifer scale and that baseflow observations are pivotal in quantifying the evapotranspiration impact.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/295802

Modelling Shallow Groundwater Evaporation Rates from a Large Tank Experiment
WATER RESOURCES MANAGEMENT
Autore/i: Colombani, N.; Fronzi, D.; Palpacelli, S.; Gaiolini, M.; Gervasio, M. P.; Marcellini, M.; Mastrocicco, M.; Tazioli, A.
Classificazione: 1 Contributo su Rivista
Abstract: A large tank (1.4 m x 4.0 m x 1.3 m) filled with medium-coarse sand was employed to measure evaporation rates from shallow groundwater at controlled laboratory conditions, to determine drivers and mechanisms. To monitor the groundwater level drawdown 12 piezometers were installed in a semi regular grid and equipped with high precision water level, temperature, and electrical conductivity (EC) probes. In each piezometer, 6 micro sampling ports were installed every 10 cm to capture vertical salinity gradients. Moreover, the soil water content, temperature and EC were measured in the unsaturated zone using TDR probes placed at 5, 20 and 40 cm depth. The monitoring started in February 2020 and lasted for 4 months until the groundwater drawdown became residual. To model the groundwater heads, temperature, and salinity variations SEAWAT 4.0 was employed. The calibrated model was then used to obtain the unknown parameters, such as: maximum evaporation rates (1.5-4.4 mm/d), extinction depth (0.90 m), mineral dissolution (5.0e-9 g/d) and evaporation concentration (0.35 g/L). Despite the drawdown was uniformly distributed, the increase of groundwater salinity was rather uneven, while the temperature increase mimicked the atmospheric temperature increase. The initial groundwater salinity and the small changes in the evaporation rate controlled the evapoconcentration process in groundwater, while the effective porosity was the most sensitive parameter. This study demonstrates that shallow groundwater evaporation from sandy soils can produce homogeneous water table drawdown but appreciable differences in the distribution of groundwater salinity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/292982

The issue of groundwater salinization in coastal areas of the mediterranean region: A review
WATER
Autore/i: Mastrocicco, M.; Colombani, N.
Classificazione: 1 Contributo su Rivista
Abstract: The Mediterranean area is undergoing intensive demographic, social, cultural, economic, and environmental changes. This generates multiple environmental pressures such as increased demand for water resources, generation of pollution related to wastewater discharge, and land consumption. In the Mediterranean area, recent climate change studies forecast large impacts on the hydrologic cycle. Thus, in the next years, surface and ground-water resources will be gradually more stressed, especially in coastal areas. In this review paper, the historical and geographical distribution of peer-review studies and the main mechanisms that promote aquifer salinization in the Mediterranean area are critically discussed, providing the state of the art on topics such as actual saltwater wedge characterization, paleo-salinities in coastal areas, water-rock interactions, geophysical techniques aimed at delineating the areal and vertical extent of saltwater intrusion, management of groundwater overexploitation using numerical models and GIS mapping techniques for aquifer vulnerability to salinization. Each of the above-mentioned approaches has potential advantages and drawbacks; thus, the best tactic to tackle coastal aquifer management is to employ a combination of approaches. Finally, the number of studies focusing on predictions of climate change effects on coastal aquifers are growing but are still very limited and surely need further research.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298611

Actual and forecasted vulnerability assessment to seawater intrusion via galdit-susi in the volturno river mouth (Italy)
REMOTE SENSING
Autore/i: Busico, G.; Buffardi, C.; Ntona, M. M.; Vigliotti, M.; Colombani, N.; Mastrocicco, M.; Ruberti, D.
Classificazione: 1 Contributo su Rivista
Abstract: Coastal areas have become increasingly vulnerable to groundwater salinization, especially in the last century, due to the combined effects of climate change and growing anthropization. In this study, a novel methodology named GALDIT-SUSI was applied in the floodplain of the Volturno River mouth for the current (2018) and future (2050) evaluation of seawater intrusion accounting for the expected subsidence and groundwater salinization rates. Several input variables such as digital surface model, land use classification, subsidence rate and drainage system have been mapped via remote sensing resources. The current assessment highlights how areas affected by salinization coincide with the semiperennial lagoons and inland depressed areas where paleosaline groundwaters are present. The future assessment (2050) shows a marked increase of salinization vulnerability in the coastal strip and in the most depressed areas. The results highlight that the main vulnerability driver is the Revelle index, while predicted subsidence and recharge rates will only slightly affect groundwater salinization. This case study indicates that GALDIT-SUSI is a reliable and easy-to-use tool for the assessment of groundwater salinization in many coastal regions of the world.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/298612

Evaluating SWAT Performance to Quantify the Streamflow Sediment Yield in a Highly Urbanized Basin
The 4th EWaS International Conference: Valuing the Water, Carbon, Ecological Footprints of Human Activities
Autore/i: Busico, Gianluigi; Colombani, Nicolo; Fronzi, Davide; Tazioli, Alberto; Mastrocicco, Micol
Editore: MDPI
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Hydrological predictive models represent the most recently developed tools in the field of water simulation. In this study, the Soil and Water Assessment Tool (SWAT) model was applied in the Aspio basin in central Italy. After a calibration and validation procedure based on daily streamflow-observed data, the sediment erosion rate from the basin was estimated in the 4 years of simulation. The years of 2016 and 2018 were characterized by a higher amount of transported sediment, which coincided with the run-off peaks events. Regarding the land-use classification, this study shows how the agricultural and artificial areas provide a higher contribution to the transported sediments. This study shows that SWAT can be used for land management in highly urbanized watersheds.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/346343

Soil conditioners effects on hydraulic properties, leaching processes and denitrification on a silty-clay soil
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Colombani, N.; Gervasio, M. P.; Castaldelli, G.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Agricultural landscapes are often affected by groundwater quality issues due to fertilizers leaching. To address this worldwide problem several agricultural best practices have been proposed, like limiting the amount of fertilizers and increasing soil organic matter content. To evaluate if these practices may promote groundwater quality enhancement, vadose zone retention time and complex biogeochemical processes must be known in detail. In this study, sequential undisturbed column experiments were performed to determine the amount of nutrients and heavy metals leached after simulated stormwater events. The column was amended with urea then flushed for two pore volumes, then straw residuals were incorporated and flushed for two pore volumes and finally compost was incorporated and flushed for six pore volumes. Dissolved ions, major gasses and heavy metals were determined in leachate samples. Nitrate and nitrite were leached in the urea treatment producing the highest concentrations, followed by compost and straw residuals. The redox conditions were aerobic in all treatments and pH was circumneutral or slightly basic. Denitrification was low but increased with the addition of straw residuals and compost. Heavy metals were all at very low concentrations except for lead and cadmium, which slightly exceeded threshold limits (10 and 1 μg/L, respectively) in all the treatments. The compost treatment, after three pore volumes, was affected by clay swelling due to sodium dispersion, which in turn provoked a reduction of porosity and hydraulic conductivity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286822

A novel hybrid method of specific vulnerability to anthropogenic pollution using multivariate statistical and regression analyses
WATER RESEARCH
Autore/i: Busico, G.; Kazakis, N.; Cuoco, E.; Colombani, N.; Tedesco, D.; Voudouris, K.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Groundwater resources are the main supply of freshwater for human activities. However, in the last fifty years aquifers have become more susceptible to chemical pollution due to human activities. The concept of groundwater vulnerability constitutes a worldwide accepted tool for water protection and planning. However, the existing methods and modified versions do not account for all the hydrogeochemical processes that drive anthropogenic pollution. The hydrogeochemical processes occurring within an aquifer can be determined using multivariate statistical analysis. In this study a specific vulnerability method named SVAP (Specific Vulnerability to Anthropogenic Pollution) is proposed. The index is based on seven quantitative parameters: depth to groundwater, recharge, nitrate losses, hydraulic resistance of the vadose zone, aquifer thickness, hydraulic conductivity of the aquifer, and slope. Weights of anthropogenic factors were determined by factor analysis and used to validate the SVAP methodology. The parameters’ classification was selected according to the highest Pearson's correlation coefficient with factor weights and then grouped via a linear combination. The new index was applied in two watersheds: the Florina basin (Greece) and the Garigliano River basin (Italy), both of which possess complex hydrogeochemical regimes. The main hydrogeochemical processes acting in the study areas were identified via factor analysis, which revealed that the anthropogenic pollution in both sites was due mainly to chemical fertilizers and manure. Verification of the SVAP method produced correlation coefficients with nitrate concentrations of 0.75 and 0.62 in Florina and Garigliano, respectively. The proposed SVAP method is more reliable and flexible than standard vulnerability assessment methods and can be easily adapted for complex aquifers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286815

Redox dependent arsenic occurrence and partitioning in an industrial coastal aquifer: Evidence from high spatial resolution characterization of groundwater and sediments
WATER
Autore/i: Sbarbati, C.; Barbieri, M.; Barron, A.; Bostick, B.; Colombani, N.; Mastrocicco, M.; Prommer, H.; Passaretti, S.; Zheng, Y.; Petitta, M.
Classificazione: 1 Contributo su Rivista
Abstract: Superlative levels of arsenic (As) in groundwater and sediment often result from industrial pollution, as is the case for a coastal aquifer in Southern Italy, with a fertilizer plant atop. Understanding conditions under which As is mobilized from the sediments, the source of that As, is necessary for developing effective remediation plans. Here, we examine hydrogeological and geochemical factors that affect groundwater As concentrations in a contaminated coastal aquifer. Groundwater has been subject to pump-and-treat at a massive scale for more than 15 years and is still ongoing. Nevertheless, As concentrations (0.01 to 100 mg/L) that are four orders of magnitude more than Italian drinking water standard of 10 µg/L are still present in groundwater collected from about 50 monitoring wells over three years (2011, 2016, and 2018). As was quantified in three different locations by sequential extractions of 29 sediment cores in 2018 (depth 2.5 m to −16.5 m b.g.l.), combined with groundwater As composition, the aqueous and solid partitioning of As were evaluated by partition coefficient (Kd ) in order to infer the evolution of the contaminant plumes. Most sediment As is found in easily extractable and/or adsorbed on amorphous iron oxides/hydroxides fractions based on sequential extractions. The study shows that As contamination persists, even after many years of active remediation due to the partitioning to sediment solids. This implies that the choice of remediation techniques requires an improved understanding of the biogeochemical As-cycling and high spatial resolution characterization of both aqueous and solid phases for sites of interest.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286824

Modeling soil nitrate accumulation and leaching in conventional and conservation agriculture cropping systems
WATER
Autore/i: Colombani, N.; Mastrocicco, M.; Vincenzi, F.; Castaldelli, G.
Classificazione: 1 Contributo su Rivista
Abstract: Nitrate is a major groundwater inorganic contaminant that is mainly due to fertilizer leaching. Compost amendment can increase soils' organic substances and thus promote denitrification in intensively cultivated soils. In this study, two agricultural plots located in the Padana plain (Ferrara, Italy) were monitored and modeled for a period of 2.7 years. One plot was initially amended with 30 t/ha of compost, not tilled, and amended with standard fertilization practices, while the other one was run with standard fertilization and tillage practices. Monitoring was performed continuously via soil water probes (matric potential) and discontinuously via auger core profiles (major nitrogen species) before and after each cropping season. A HYDRUS-1D numerical model was calibrated and validated versus observed matric potential and nitrate, ammonium, and bromide (used as tracers). Model performance was judged satisfactory and the results provided insights on water and nitrogen balances for the two different agricultural practices tested here. While water balance and retention time in the vadose zone were similar in the two plots, nitrate leaching was less pronounced in the plot amended with compost due to a higher denitrification rate. This study provides clear evidence that compost addition and no-tillage (conservation agriculture) can diminish nitrate leaching to groundwater, with respect to standard agricultural practices.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286820

Evaluating SWAT model performance, considering different soils data input, to quantify actual and future runoff susceptibility in a highly urbanized basin
JOURNAL OF ENVIRONMENTAL MANAGEMENT
Autore/i: Busico, G.; Colombani, N.; Fronzi, D.; Pellegrini, M.; Tazioli, A.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: The Soil and Water Assessment Tool (SWAT) is a physical model designed to predict the hydrological processes that could characterize natural and anthropized watersheds. The model can be forced using input data of climate prediction models, soil characteristics and land use scenarios to forecast their effect on hydrological processes. In this study, the SWAT model has been applied in the Aspio basin, a small watershed, highly anthropized and characterized by a short runoff generation. Three simulations setup, named SL1, SL2 and SL3, were investigated using different soil resolution to identify the best model performance. An increase of space requirement and calibration time has been registered in conjunction with the increasing soil resolution. Among all simulations, SL1 has been chosen as the best one in describing watershed streamflow, despite it was characterized by the lower soil resolution. A map of susceptibility to runoff for the entire basin was so created reclassifying the runoff amount of four years in five classes of susceptibility, from very low to very high. Eleven sub-basins, coinciding with the main urban settlements, were identified as highly susceptible to runoff generation. Considering future climate predictions, a slight increase of runoff has been forecasted during summer and autumn. The map of susceptibility successfully identified as highly prone to runoff those sub-basins where extreme flood events were yet recorded in the past, remarking the reliability of the proposed assessment and suggesting that this methodology could represent a useful tool in flood managing plan.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286821

The importance of incorporating denitrification in the assessment of groundwater vulnerability
APPLIED SCIENCES
Autore/i: Busico, G.; Kazakis, N.; Colombani, N.; Khosravi, K.; Voudouris, K.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Human activities are deeply connected with groundwater reservoirs, so protecting them from pollution has become a priority in many regions of the world. Nitrate is considered the main groundwater pollutant since it is directly linked to many human activities. Agricultural activities and domestic wastewater have been identified as the main sources of nitrate in groundwater. Nevertheless, there are some natural processes that can mitigate nitrate pollution. Together with dilution processes, the degradation of nitrate through denitrification has been acknowledge as a process that can potentially reduce nitrogen loads, in both deep and shallow aquifers. Usually these processes were not properly quantified in vulnerability assessment methods, until the introduction of LOS indices. In this study, the application of the LOS indices on 4 agricultural areas is discussed, highlighting how the LOS indices can identify portions of the landscape with higher potential denitrification and how they directly enhance the groundwater vulnerability assessment. Previous studies have shown that LOS indices are a valuable tool for proper vulnerability assessment to nitrate, however they need to be coupled with other parameters that also describe nitrate behavior in groundwater. The SINTACS-SVN and DRASTIC-PA methods that include the LOS indices, were applied for the first time in the Epanomi coastal area to evaluate the reliably of the assessment and, despite the different classes range and the weights applied, similar groundwater vulnerability assessment maps were obtained. The nitrate vulnerability maps were comparable with the observed nitrate concentrations and were found to be highly comparable with original LOS maps. Nevertheless, it should be kept in mind that vulnerability methods are only screening tools and groundwater quality observations are pivotal information for environmental management.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286816

Monitoring and Modelling Interactions between the Montagna dei Fiori Aquifer and the Castellano Stream (Central Apennines, Italy)
WATER
Autore/i: Tazioli, Alberto; Colombani, Nicolò; Palpacelli, Stefano; Mastrocicco, Micòl; Nanni, Torquato
Classificazione: 1 Contributo su Rivista
Abstract: Groundwater is the most used water resource around the world, but due to population growth and climate change the alluvial lowland aquifers are often polluted and over-exploited. Thus, more and more frequently water managers need to shift their attention to mountain regions to identify groundwater resources for drinking purposes. This study presents a monitoring and modelling approach that allowed to quantify the inflow from the "Montagna dei Fiori" fractured aquifer to the Castellano stream. Continuous monitoring of flow discharge and temperature during an entire hydrological year (2018-2019) at two monitoring stations along the stream allowed to discriminate between the baseflow (on average, 0.891 m3/s) and the run-off (on average, 0.148 m3/s) components. A hydrogeological basin-wide numerical flow model (using MODFLOW-2005) was set up using information from hydrogeological and geomechanical surveys. The model was calibrated using the daily baseflow observations made in the Castellano stream (R2 = 0.75). The calibrated model allowed to quantify groundwater/surface water interactions. After an automated sensitivity analysis (using MODFLOW-2000), the recharge was found to be the most uncertain parameter, followed by the hydraulic conductivity zonation. This methodology could be applied in other mountain regions where groundwater monitoring networks are usually lacking to improve water resources management.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/276028

Deciphering interannual temperature variations in springs of the Campania region (Italy)
WATER
Autore/i: Mastrocicco, Micòl; Busico, Gianluigi; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista
Abstract: While the effects of climate change on the thermal regimes of surface waters have already been assessed by many studies, there is still a lack of knowledge on the effects on groundwater temperature and on the effects on spring water quality. The online available dataset of the Campania Environmental Agency (ARPAC) was analysed via spatial, temporal and statistical analyses to assess the impact of climate variability on 118 springs, monitored over the period from 2002 to 2017. The meteorological dataset was used to compute average annual precipitation and atmospheric temperatures. Spring water temperatures, electrical conductivity, pH, chloride and fluoride were selected to determine if climate variations had a significant impact on spring water quality. This study shows that the Campania region has experienced an increase of spring water temperatures of approximately 2.0 °C during the monitored period. This is well-linked with the increase of atmospheric minimum temperatures, but not with average and maximum atmospheric temperatures. The spring water temperature increases were not reflected by a concomitant change of the analysed water quality parameters. The latter were linked to the precipitation trend and other local factors, like spring altitude and the presence of geothermal heat fluxes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265115

Modelling actual and future seawater intrusion in the variconi coastal wetland (Italy) due to climate and landscape changes
WATER
Autore/i: Mastrocicco, M.; Busico, G.; Colombani, N.; Vigliotti, M.; Ruberti, D.
Classificazione: 1 Contributo su Rivista
Abstract: Coastal freshwater resources are commonly under high risk of being contaminated from seawater. The main processes that affect seawater intrusion are groundwater overexploitation, land use change, and climate change effects. In this context coastal lagoons represent the more sensitive environments prone to seawater intrusion. Numerical modelling is a useful tool to understand and predict seawater intrusion. In this study, a three-dimensional SEAWAT model is employed to simulate the seawater intrusion to coastal aquifers of Variconi Oasis (Italy). The present simulation was divided into a calibration and a validation model, then the model was used to predict the salinization trend up to 2050. Results show the role of the sea in salinizing the beach front, while the retrodunal environment is characterized by transitional environments. Future seawater intrusion scenarios considering only climate data showed no significative differences in respect to the actual situation. The same happens considering also a low sea level rise prediction. On the contrary, the worst scenario (high sea level rise prediction), depicts a quite different situation, with a saline intrusion in the Variconi oasis that will severely affect the fragile transitional ecosystem. This modelling framework can be used to quantify the effects of climate changes in similar coastal environments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272810

Contrasting biogeochemical processes revealed by stable isotopes of H2O, N, C and S in shallow aquifers underlying agricultural lowlands
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Colombani, N.; Mastrocicco, M.; Castaldelli, G.; Aravena, R.
Classificazione: 1 Contributo su Rivista
Abstract: Lowland coastal areas as the Po Delta (Italy) are often intensively cultivated and affected by nitrogen imbalance due to fertilizers leaching to groundwater and export via run-off. To address this issue several agricultural best practices have been proposed, like limiting the amount of fertilizers and increasing soil organic matter content. In this study, groundwater samples were analysed for major ions and stable isotopes of H2O, C, N and S using multi-level sampler (MLS) from two contrasting depositional environments, one representative of alluvial plain (AP) and the other representative of a reclaimed coastal plain (RCP). In each site, controlled plots with different agriculture practice including fertilizers and tillage and compost amendment and no tillage were considered in the study. Tracer test results highlight that recharge water infiltrated at the start of the controlled study has not yet reached the saturated zone, thus current groundwater concentrations are representative of former agricultural practices. Stable isotopes show a clear distinction between different sources of nitrogen in both sites, from synthetic fertilizers to sedimentary nitrogen pool and atmospheric input. The main source of sulphate in groundwater is pyrite and fertilizers. Denitrification, sulphate reduction and methanogenesis were involved in the C, N and S cycle in the RCP site characterized by low hydraulic conductivity sediments and high SOM. These processes were not relevant in the AP site characterized by oxic condition and low SOM, but some evidence of denitrification was found in one of the AP sites. High resolution monitoring was a key tool to identify the different redox zones responsible for N, C and S cycling in these aquifers. This study shows that a clear understanding of transit times in the vadose zone is a key prerequisite to evaluate the effect of controlled agriculture practice on the quality of shallow groundwater.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272807

A hybrid GIS and AHP approach for modelling actual and future forest fire risk under climate change accounting water resources attenuation role
SUSTAINABILITY
Autore/i: Busico, G.; Giuditta, E.; Kazakis, N.; Colombani, N.
Classificazione: 1 Contributo su Rivista
Abstract: Forest wildfires usually occur due to natural processes such as lightning and volcanic eruptions, but at the same time they are also an eect of uncontrolled and illegal anthropogenic activities. Dierent factors can influence forest wildfires, like the type of vegetation, morphology, climate, and proximity to human activities. A precise evaluation of forest fire issues and of the countermeasures needed to limit their impact could be satisfactory especially when forest fire risk (FFR) mapping is available. Here, we proposed an FFR evaluation methodology based on Geographic Information System (GIS) and the analytic hierarchy process (AHP). The study area is the Campania region (Southern Italy) that, for the last 30 years, has been aected by numerous wildfires. The proposed methodology analyzed 12 factors, and AHP was used for weight assignment, oering a new approach to some parameters. The method divided the study area into five risk classes, from very low to very high. Validation with fire alerts showed a good correlation between observed and predicted fires (0.79 R2). Analyzing the climate projections, a future FFR for 2040 was also assessed. The proposed methodology represents a reliable screening tool to identify areas under forest fire risk, and can help authorities to direct preventive actions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/301852

Nitrogen budget of Short Rotation forests amended with digestate in highly permeable soils
APPLIED SCIENCES
Autore/i: Gumiero, B.; Candoni, F.; Boz, B.; Da Borso, F.; Colombani, N.
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272809

Intense rainfalls trigger nitrite leaching in agricultural soils depleted in organic matter
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Mastrocicco, Micòl; Colombani, Nicolò; Soana, Elisa; Vincenzi, Fabio; Castaldelli, Giuseppe
Classificazione: 1 Contributo su Rivista
Abstract: Nitrate and ammonium are common inorganic contaminants of anthropogenic origin in many shallow aquifers around the world, while nitrite is less common, but it is most harmful than nitrate and ammonium due to its high reactivity. This paper presents evidence of nitrite accumulation after intense rainfalls in soil samples collected in an agricultural field characterized by organic matter chronic depletion. Moreover, an intact core from the same site was also collected to perform an unsaturated column experiment (60 cm long and 20 cm outer diameter) mimicking heavy rainfalls (230 mm in 2 days). Results from the field site showed nitrite accumulation (up to 0.45 mmol/kg) at 50–70 cm depth, just below the plough layer. The column experiment showed very high initial concentrations of nitrate and nitrite in the leachate and a progressive decrease of nitrate due to denitrification. The numerical flow model was calibrated versus the observed volumetric water contents and leachate flow rates. The numerical reactive transport model was calibrated versus the leachate concentrations of six dissolved species (ammonium, nitrate, nitrite, dissolved organic carbon, chloride and bromide). The optimized model resulted to be robustly calibrated providing insights on the kinetic rates driving the production, accumulation and leakage of nitrite, showing that incomplete denitrification is the source of nitrite. As far as the authors are aware, this is the first study reporting a clear link between high nitrite leaching rates and extreme rainfall events in lowland agricultural soils depleted in organic matter. The proposed methodology could be applied to quantify nitrite cycling processes in many other agricultural areas of the world affected by extreme rainfall events
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265024

GALDIT-SUSI a modified method to account for surface water bodies in the assessment of aquifer vulnerability to seawater intrusion
JOURNAL OF ENVIRONMENTAL MANAGEMENT
Autore/i: Kazakis, Nerantzis; Busico, Gianluigi; Colombani, Nicolò; Mastrocicco, Micòl; Pavlou, Athanasios; Voudouris, Konstantinos
Classificazione: 1 Contributo su Rivista
Abstract: The salinization of coastal aquifers is one of the major environmental issue worldwide. Overexploitation is the most common reason of salinization, since it generates a piezometric inversion, which in turn leads to groundwater flow from the coast towards inland. This also occurs in water bodies connected to the sea like lagoons, rivers, torrents and wetlands. In this study, a modification of the GALDIT method including “SUperficial Seawater Intrusion (SUSI)” is proposed. Six new parameters were added to the classical ones. The analytical hierarchy process and the sensitivity analysis were performed for weights definition and validation of the proposed GALDIT-SUSI method. Two study areas, with different characteristics were chosen for the application of both methods: the coastal area of Epanomi (Greece) and the Po River lowland (Italy). The application of the standard GALDIT in both sites showed a poor discrimination of the vulnerability to seawater intrusion, confining it only in proximity to the coastline. Conversely, GALDIT-SUSI divided the two sites in five classes of vulnerability ranging from very low to very high, stressing the higher vulnerability of lagoons and wetland for Epanomi and lagoons and rivers for the Po River lowland. GALDIT-SUSI is easy to apply and versatile, since it can be adapted to the specific hydrogeological setting of the area of interest. Moreover, GALDIT-SUSI can be further improved to deal with other salinization mechanisms.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265113

Reactive nitrogen losses via denitrification assessed in saturated agricultural soils
GEODERMA
Autore/i: Castaldelli, Giuseppe; Colombani, Nicolò; Soana, Elisa; Vincenzi, Fabio; Fano, Elisa Anna; Mastrocicco, Micol
Classificazione: 1 Contributo su Rivista
Abstract: The aim of the present study was to quantify nitrate (NO3 −) removal via denitrification in an intensively cropped lowland of the Po River delta (Northern Italy). These agricultural lands are characterized by fine textured soils, generally poor of labile organic matter and amended mainly with synthetic fertilizers. Laboratory core incubations in water saturation conditions were performed on two contrasting soil types distinguished by different soil textures (silty-loam and silty-clay) either amended with NO3 − alone or a combination of NO3 − and acetate. Denitrification was evaluated by concomitant measurements of NO3 − consumption and N2 production via N2:Ar analyses by Membrane Inlet Mass Spectrometry (MIMS). The water-logged soils showed higher capacity to reduce NO3 − to N2 when supplied with acetate as an organic substrate, while, without acetate amendment, NO3 − removal was limited due to lack of labile organic substrates. Transient nitrite (NO2 −) accumulation was documented in acetate amended mesocosms, due to concurrent presence of elevated pH values and use of highly oxidized substrates (like acetate). This study suggests that agricultural practices aimed to increase the availability of labile organic matter, such as acetate, are beneficial in buffering reactive N excess in soils and to reduce NO3 − leaching towards groundwater and surface-water.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265114

Effect of ebullition and groundwater temperature on estimated dinitrogen excess in contrasting agricultural environments
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Mastrocicco, M.; Soana, E.; Colombani, N.; Vincenzi, F.; Castaldi, S.; Castaldelli, G.
Classificazione: 1 Contributo su Rivista
Abstract: Denitrification is a key microbial-mediated reaction buffering the impact of agriculturally-derived nitrate loads. Groundwater denitrification capacity is often assessed by measuring the magnitude and patterns of dinitrogen excess, although this method can be biased by dissolved gasses exsolution and ebullition. To address this issue, shallow groundwater was sampled in two field sites via nested mini-wells on a monthly basis over an entire hydrological year and analysed for dissolved gasses, nitrate and physical parameters. Both sites are located in lowland areas of the Po River basin (Italy) and are characterized by intensive agriculture. The GUA site, a freshwater paleo-river environment, with a low content of organic matter (SOM) and oxic sub-oxic groundwater. The BAN site, a reclaimed brackish swamp environment, with abundant SOM and sulphidic-methanogenic groundwater. Groundwater samples evidenced a general deficit of dinitrogen and Argon concentrations, because of ebullition induced by a total dissolved gasses pressure exceeding the hydrostatic pressure. Ebullition was recorded only during winter at the reclaimed brackish soil and was triggered by methane exsolution. While in summer both sites were affected by ebullition because of the water table drawdown. Denitrification evaluated using dinitrogen excess via dinitrogen-Argon ratio technique, was not only affected by gas exsolution, but also by groundwater temperature fluctuations. In fact, the latter induced large biases in the calculated N-2 excess even in the freshwater paleo-river environment. For these reasons, dinitrogen excess estimate with standard methods resulted to be unreliable in both lowland environments and a modified method is here presented to overcome this issue.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272808

Direct measurement of dissolved dinitrogen to refine reactive modelling of denitrification in agricultural soils
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Mastrocicco, Micòl; Colombani, Nicolò; Castaldelli, Giuseppe
Classificazione: 1 Contributo su Rivista
Abstract: Nitrogen fertilizers used in agriculture often cause nitrate leaching towards shallow groundwater, especially in lowland areas where soil permeability, ploughing, clay content, and the flat topography minimizes surface runoff. The introduction of good agricultural practices to reduce the nitrate amount entering the groundwater system is crucial to ameliorate the kinetic control on nitrate denitrification capacity. With this aim, a series of anaerobic mesocosms, consisting of loamy and clay soils and nitrate rich water, were modelled using acetate and natural organic matter as electron donors. Acetate was chosen because it is the main intermediate in many biodegradation pathways of organic compounds, and hence it is a suitable carbon source for denitrification. To account for the spatial variability of soil parameters, the experiments were performed in triplicates. The geochemical code PHREEQC(3) was used to simulate kinetic denitrification, and equilibrium reactions of gas and mineral phases. The reactive modelling results highlighted a rapid acetate and nitrate degradation rate, a rapid production of dissolved inorganic carbon and dinitrogen, and a steady concentration of dissolved iron and sulphate, suggesting that the main pathway of nitrate attenuation is through denitrification; concomitantly excluding the occurrence of other processes leading to nitrate consumption. In the absence of acetate, the loamy soil, poor of natural organic matter, did not allow to complete the denitrification process. This modelling study investigates in detail the relationship between the denitrification process in natural soils, with excess and in limitation of organic substrates, and the occurrence and fate of dissolved dinitrogen analysed with a high precision membrane inlet mass spectrometer. Results demonstrate that modelling nitrate degradation processes as a whole, using geochemical datasets and codes, will improve the estimates of agricultural landscapes denitrification and support better nitrogen management, especially in lowland environments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265117

A special issue of Geosciences: Groundwater pollution
GEOSCIENCES
Autore/i: Mastrocicco, Micòl; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265122

Assessing aquifer salinization with multiple techniques along the Southern Caspian Sea shore (Iran)
WATER
Autore/i: Golshan, Mohammad; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: This study focuses on the salinization of the coastal aquifer in the Mazandaran Province (Iran) within four different sites. Many factors can lead to declining groundwater quality, but this study focuses on the seawater intrusion area. Therefore, locating the interface between saltwater and freshwater is very important. For this purpose, three characterization methods with different accuracies have been employed: the Verruijt equation, vertical resistivity sounding, and an electromagnetic survey. Vertical resistivity sounding and the electromagnetic survey were performed near existing exploration boreholes and were used to determine the saltwater interface. The results showed that the Verruijt equation provides a reliable localization in two of the sites, but in the other two sites, the determined interface is lower than the observed data. The geoelectrical method showed acceptable results, but often this method cannot distinguish between the saltwater and saline aquitard boundary. The electromagnetic method showed a high accuracy in all the study sites and proved to be the most reliable method compared with the other techniques employed in this study. The results from this study are useful in helping to identify the most suitable technique for locating the freshwater/saltwater interface, especially in those sites where a detailed characterization via multilevel sampling is not feasible for technical or economic reasons.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265175

Limitations of GALDIT to map seawater intrusion vulnerability in a highly touristic coastal area
IOP Conference Series: Earth and Environmental Science
Autore/i: Kazakis, N.; Busico, G.; Colombani, N.; Mastrocicco, M.; Voudouris, K.
Editore: Institute of Physics Publishing
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Coastal aquifers are susceptible to seawater intrusion, especially touristic areas where the overexploitation combined with the agricultural use of groundwater represent a severe issue for water management. GALDIT methodology was applied as a management tool to identify and prevent salinization of the aquifer. GALDIT methodology needs six input parameters: groundwater occurrence (G), aquifer hydraulic conductivity (A), groundwater head above sea level (L), distance from the shore (D), impact of the existing status of seawater intrusion (I), and thickness of the aquifer (T). Then a contour map is created using three degree of vulnerability: high, medium and low. The higher vulnerability zone ranges from 40 to 550 m towards the mainland with the rest of the aquifer characterized by medium vulnerability. The main problem affecting the selected field site is the large water requirement during the summer period due to the touristic activities, but the correct use of surplus water collected in the winter can overcome this problem. This study demonstrates that further investigation on groundwater hydrochemistry and on water demand trends from the different activities impacting the field site should be implemented, in order to guarantee environmental and touristic development sustainability.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265121

Reactive and mixing processes governing ammonium and nitrate coexistence in a polluted coastal aquifer
GEOSCIENCES
Autore/i: Sbarbati, Chiara; Colombani, Nicolò; Mastrocicco, Micòl; Petitta, Marco; Aravena, Ramon
Classificazione: 1 Contributo su Rivista
Abstract: A comprehensive hydrochemical, stable isotope and microbial analyses characterisation has been performed to evaluate the sources of groundwater, nitrogen pollution and degradation processes occurring in an industrial polluted coastal aquifer in the framework of a complex hydrodynamic system. The coexistence of ammonium and nitrate has been observed in almost all the investigated monitoring wells, reaching maximum values of 100 and 200 mg/L for both species. Chloride and potassium concentration coupled with groundwater stable isotopes data show the influence of local and urban recharge and the occurrence of seawater intrusion in areas near the coastline. 15N–NH4 + values ranging between 4.9 and +14.9% suggest that different processes such as partial nitrification of ammonium, probably anammox activities and sorption, are occurring at the site. The isotope data for NH4+ also showed the existence of the remnant of an old fertilizer plume in the downgradient area. The nitrate isotope data ranging between +9 and +46% and +6 and +26% for 15N–NO3 and 18O–NO3, respectively, suggest that nitrate content is attenuated by denitrification and probably annamox. The fast groundwater flow field is one of the reasons for the coexistence of NH4 + and NO3 in groundwater, since both compounds can penetrate the reducing zone of the aquifer. The influence of leakage of sewage pipelines on the aquifer cannot be discerned due to the complexities of the nitrogen attenuation processes, also influenced by pumping activities.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265127

Recognition of the anthropogenic contribution to the input of fluoride in urban recharge
ENVIRONMENTAL EARTH SCIENCES
Autore/i: Colombani, N.; Kebede, S.; Salemi, E.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Fluoride is a common inorganic contaminant of geogenic origin around the world. Anthropogenic sources of fluoride could also contribute to increased fluoride concentrations in groundwater, although they have not been well-documented. This paper presents soil batches and unsaturated column experiments on fluoride-enriched recharge water percolating from a urine-polluted soil in an area where fluorosis is endemic. Results from the polluted soil collected near a main street in Addis Ababa (Ethiopia) are compared with an unpolluted soil collected in a garden inside the university campus, located 50 m from the polluted one. Soils were sampled at the end of the dry season and after the first intense rainfall at the beginning of the wet season. The objectives of the study were to evaluate the anthropogenic fluoride enrichment in urban recharge due to unmanaged human excretions along the streets and model recharge water fluxes and solutes leaching to evaluate the reactivity of dissolved species. Batch experiments found extremely high fluoride (42.1 ± 5.2 mg/kg) and urea (89.5 ± 8.1 mg/ kg) concentrations in polluted soil before the rainy season. The fluoride concentration in the polluted soil was more than one order of magnitude higher than that recorded in the uncontaminated soil. This study proved that in areas where the population is subject to a large fluoride daily intake, recharge waters extremely enriched in fluoride can be leached from urine-contaminated soils in urban environments. The proposed methodology could be applied for a first screening for the anthropogenic sources of fluoride in urban recharge.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265128

Assessment of the anthropogenic fluoride export in Addis Ababa urban environment (Ethiopia)
JOURNAL OF GEOCHEMICAL EXPLORATION
Autore/i: Colombani, N.; Di Giuseppe, D.; Kebede, S.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Protection of natural waters against excess of fluoride is a priority in the Middle Ethiopian Rift where high concentrations of fluoride occur in groundwater, lakes and hot springs. In recent years, a growing attention has been paid to geogenic sources of fluoride, while anthropogenic sources have been completely disregarded. Ethiopian people are subject to high levels of fluoride intake via food or drinks, resulting in elevated concentrations of fluoride in urine and subsequently in the human slurry waste. In Addis Ababa, 3 millions of people live without a suitable sewage waste collection/treatment facility and the superficial water system of the city often receives untreated domestic and municipal effluents. In this study, the impact of fluoride-rich human slurry on surface waters quality in Addis Ababa was evaluated. Physical-chemical and bacteriological assessments of rivers and shallow groundwater samples were performed. Several samples displayed critical levels of fluoride and faecal coliforms bacteria in the north-western part of the city. When uncontaminated fresh water flowing from the highland travels through the city, it experiences a rapid deterioration because of the interaction with untreated sewage outlets. This was clearly inferred by the combined analysis of water stable isotopes, fluoride and faecal coliforms bacteria. The methodological results of this study could be used to distinguish anthropogenic from geogenic sources of fluoride in urban environments of developing countries, which are often affected by multiple sources of fluoride.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265123

Multivariate statistical analysis to characterize/discriminate between anthropogenic and geogenic trace elements occurrence in the Campania Plain, Southern Italy
ENVIRONMENTAL POLLUTION
Autore/i: Busico, Gianluigi; Cuoco, Emilio; Kazakis, Nerantzis; Colombani, Nicolò; Mastrocicco, Micòl; Tedesco, Dario; Voudouris, Konstantinos
Classificazione: 1 Contributo su Rivista
Abstract: Shallow aquifers are the most accessible reservoirs of potable groundwater; nevertheless, they are also prone to various sources of pollution and it is usually difficult to distinguish between human and natural sources at the watershed scale. The area chosen for this study (the Campania Plain) is characterized by high spatial heterogeneities both in geochemical features and in hydraulic properties. Groundwater mineralization is driven by many processes such as, geothermal activity, weathering of volcanic products and intense human activities. In such a landscape, multivariate statistical analysis has been used to differentiate among the main hydrochemical processes occurring in the area, using three different approaches of factor analysis: (i) major elements, (ii) trace elements, (iii) both major and trace elements. The elaboration of the factor analysis approaches has revealed seven distinct hydrogeochemical processes: i) Salinization (Cl−, Na+); ii) Carbonate rocks dissolution; iii) Anthropogenic inputs (NO3 −, SO4 2−, U, V); iv) Reducing conditions (Fe2+, Mn2+); v) Heavy metals contamination (Cr and Ni); vi) Geothermal fluids influence (Li+); and vii) Volcanic products contribution (As, Rb). Results from this study highlight the need to separately apply factor analysis when a large data set of trace elements is available. In fact, the impact of geothermal fluids in the shallow aquifer was identified from the application of the factor analysis using only trace elements. This study also reveals that the factor analysis of major and trace elements can differentiate between anthropogenic and geogenic sources of pollution in intensively exploited aquifers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265538

Soil type and microclimatic conditions as drivers of urea transformation kinetics in maize plots
CATENA
Autore/i: Castaldelli, Giuseppe; Colombani, Nicolò; Tamburini, Elena; Vincenzi, Fabio; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: This study presents a multidisciplinary approach (hydrological, microbiological, agronomic) to determine the dynamics of transformation of synthetic urea applied as soil fertilizer during maize production. The approach consisted in field and laboratory experiments on urea hydrolysis, ammonia volatilisation and nitrification, in four soil types (named Silty-loam, Silty-clay, Peat and Sand) intensively fertilized with synthetic urea. The field plots were modelled with HYDRUS-1D to determine the fate and transport of N species in the top soils. The numerical models successfully captured the main N transformations throughout the simulated period. In addition to the field monitoring of nitrogen species, microbial C and N, and urease activity were screened in each soil. The field soil sampling highlighted that the kinetics of ammonification was consistent with the hydrolysis of urea except for the sandy soil; kinetics of ammonification decreased in the order: Silty-clay > Peat ≫ Silty-loam > Sand. The differences of urease activities and nitrification potential rates between soils supported the measured field nitrification rates, and were as follow in order of decreasing rate: Silty-clay > Silty-loam ≥ Peat > Sand. The lowest nitrification rates pertained to the inherently more vulnerable sandy soil due to the scarcity of nitrifiers. The performance of volatilization was as follow in order of decreasing rate: Sand ≫ Silty-loam ≥ Peat > Silty-clay; but in general very low volatilization rates were found. This was imputed to the concurrence of both elevated soil CEC that promoted ammonium sorption and to low wind speed in the monitored plots. The presented multidisciplinary approach should be employed in many other agricultural settings to obtain robust data for numerical models simulations on the fate and transport of reactive N species in agricultural lands.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265124

Natural and NH4+-enriched zeolitite amendment effects on nitrate leaching from a reclaimed agricultural soil (Ferrara Province, Italy)
NUTRIENT CYCLING IN AGROECOSYSTEMS
Autore/i: Faccini, Barbara; Di Giuseppe, Dario; Ferretti, Giacomo; Coltorti, Massimo; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: In this paper we report an overview of the main outcomes of a 3-years experimental cultivation carried out in an Italian reclaimed agricultural field amended with different types of zeolitites (rock containing[50% of zeolites), under cereals cultivation (Sorghum vulgare Pers, Zea mays and Triticum durum). The aim of the experiment was to exploit the properties of zeolite-rich volcanic rocks (zeolitites) for reducing the excessively high NO3- content in the soil and in waters flowing out the sub-surface drainage system of the field and flushing into the surface water system, reducing concomitantly also chemical fertilization application rates (up to 50%). Zeolitites were tested both in their natural state and in a NH4-enriched form, obtained through an enrichment process with NH4-rich zoo-technical effluents (pig slurry). NO3- content in soils and in waters discharged through SSDS were periodically monitored during the experimentation and crop yield quantified. Results showed that, for three consecutive cultivation cycles, the overall NO3- concentrations in water extracts was reduced by 45% in the zeolitite treated soils, while in SSDS waters the reduction reached the 64%. Notwithstanding the lower N input from chemical fertilizers, crop yield was not negatively affected in the zeolitite amended soils with respect to the control. Zeolitite addition increased thus soil NH4+ retention and probably influenced several pathways of N losses, allowing a better fertilizer use efficiency by plants and a reduction of the overall NO3- concentrations in the surface waters.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265181

Short-Term Response of Soil Microbial Biomass to Different Chabazite Zeolite Amendments
PEDOSPHERE
Autore/i: Ferretti, Giacomo; Keiblinger, Katharina Maria; DI GIUSEPPE, Dario; Faccini, Barbara; Colombani, Nicolò; ZECHMEISTER-BOLTENSTERN, Sophie; Coltorti, Massimo; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Zeolitites (ZTs) are rocks containing more than 50% of zeolite minerals and are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen (N) use efficiency. However, little is known about their effects on soil microbial biomass. This study aimed to evaluate short-term effects of different chabazite-rich ZT (CHAZT) amendments on soil microbial biomass and activity. A silty-clay agricultural soil was amended in three different ways, including the addition of natural (5% and 15%) and NH4 -enriched (10%) CHAZT. Soil dissolved organic carbon (C), total dissolved N, NH4 , NO3 , NO2 , microbial biomass C and N, and ergosterol were measured periodically over 16 d in a laboratory incubation. To verify the microbial immobilization of the N derived from NH4 -enriched CHAZT, a high 15N source was used for enriching the mineral to measure the microbial biomass 15N signature. An increase in the ergosterol content was observed in the soil amended with 5% natural CHAZT. However, no similar result was observed in the soil amended with 15% natural CHAZT, suggesting that the fungal biomass was favored at a lower CHAZT application rate. In the soil amended with NH4 -enriched CHAZT, microbial biomass N was related to NO3 production over time and inversely related to NH4, suggesting high nitrification process. Isotopic measurements on microbial biomass confirmed immediate assimilation of N derived from NH4 -enriched CHAZT. These results suggested that the NH4 -enriched CHAZT used in this study supplied an immediately available N pool to the microbial biomass.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265131

High-resolution global grids of revised Priestley-Taylor and Hargreaves-Samani coefficients for assessing ASCE-standardized reference crop evapotranspiration and solar radiation
EARTH SYSTEM SCIENCE DATA
Autore/i: Aschonitis, Vassilis G.; Papamichail, Dimitris; Demertzi, Kleoniki; Colombani, Nicolo; Mastrocicco, Micol; Ghirardini, Andrea; Castaldelli, Giuseppe; Fano, Elisa-Anna
Classificazione: 1 Contributo su Rivista
Abstract: The objective of the study is to provide global grids (0.5°) of revised annual coefficients for the Priestley-Taylor (P-T) and Hargreaves-Samani (H-S) evapotranspiration methods after calibration based on the ASCE (American Society of Civil Engineers)-standardized Penman-Monteith method (the ASCE method includes two reference crops: short-clipped grass and tall alfalfa). The analysis also includes the development of a global grid of revised annual coefficients for solar radiation (R s ) estimations using the respective Rs formula of H-S. The analysis was based on global gridded climatic data of the period 1950-2000. The method for deriving annual coefficients of the P-T and H-S methods was based on partial weighted averages (PWAs) of their mean monthly values. This method estimates the annual values considering the amplitude of the parameter under investigation (ETo and R s ) giving more weight to the monthly coefficients of the months with higher ETo values (or Rs values for the case of the H-S radiation formula). The method also eliminates the effect of unreasonably high or low monthly coefficients that may occur during periods where ETo and Rs fall below a specific threshold. The new coefficients were validated based on data from 140 stations located in various climatic zones of the USA and Australia with expanded observations up to 2016. The validation procedure for ETo estimations of the short reference crop showed that the P-T and H-S methods with the new revised coefficients outperformed the standard methods reducing the estimated root mean square error (RMSE) in ETo values by 40 and 25%, respectively. The estimations of Rs using the H-S formula with revised coefficients reduced the RMSE by 28% in comparison to the standard H-S formula. Finally, a raster database was built consisting of (a) global maps for the mean monthly ETo values estimated by ASCE-standardized method for both reference crops, (b) global maps for the revised annual coefficients of the P-T and H-S evapotranspiration methods for both reference crops and a global map for the revised annual coefficient of the H-S radiation formula and (c) global maps that indicate the optimum locations for using the standard P-T and H-S methods and their possible annual errors based on reference values. The database can support estimations of ETo and solar radiation for locations where climatic data are limited and it can support studies which require such estimations on larger scales (e.g. country, continent, world). The datasets produced in this study are archived in the PANGAEA database (https://doi.org/10.1594/PANGAEA.868808) and in the ESRN database (http://www.esrn-database.org or http://esrn-database.weebly.com).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265773

Modelling the salinization of a coastal lagoon-aquifer system
IOP Conference Series: Earth and Environmental Science
Autore/i: Colombani, N.; Mastrocicco, M.
Editore: Institute of Physics Publishing
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this study, a coastal area constituted by alternations of saline-brackish lagoons and freshwater bodies was studied and modelled to understand the hydrological processes occurring between the lagoons, the groundwater system of the Po River Delta (Italy) and the Adriatic Sea. The contribution of both evaporation and anthropogenic factors on groundwater salinization was assessed by means of soil, groundwater and surface water monitoring. High-resolution multi-level samplers were used to capture salinity gradients within the aquifer and surface water bodies. Data were employed to calibrate a density-dependent numerical transport model implemented with SEAWAT code along a transect perpendicular to the coast line. The results show that the lagoon is hydraulically well connected with the aquifer, which provides the major source of salinity because of the upcoming of paleo-seawater from the aquitard laying at the base of the unconfined aquifer. On the contrary, the seawater (diluted by the freshwater river outflow) creates only a limited saltwater wedge. The increase in groundwater salinity could be of serious concern, especially for the pinewood located in the dune near the coast, sensitive to salinity increases. This case study represents an interesting paradigm for other similar environmental setting, where the assumption of classical aquifer salinization from a saltwater wedge intruding from the sea is often not representative of the actual aquifer's salinization mechanisms.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265688

Impact of climate variability on the salinization of the coastal wetland-aquifer system of the Po Delta, Italy
JOURNAL OF WATER SUPPLY: RESEARCH AND TECHNOLOGY. AQUA
Autore/i: Colombani, Nicolò; Giambastiani, Beatrice M. S.; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Deltaic coastal areas are constituted by a patchwork of brackish lagoons and freshwater bodies; these coastal wetland-aquifer systems are fragile ecosystems that usually respond quickly to climate changes. To understand the hydrological processes occurring within the lagoons and the groundwater system of the Po River Delta (Italy), the contribution of both evaporation and anthropogenic factors on groundwater salinization was assessed. A time series (2002-2015) of monthly average climatic data and a temperature-salinity dataset were used in three adjacent salinebrackish lagoons with the aim to identify the actual evaporation patterns and predict future trends using artificial neural networks (ANN). Moreover, the use of groundwater and surface water equivalent freshwater heads, along with the geological architecture, allowed linking the fluctuation of lagoon salinities with the degree of hydraulic connection between wetland and aquifer system. Results show that the less a lagoon is hydraulically connected with the aquifer, the higher is the salinity peak that could be reached at the end of the summer period. ANN forecasts highlight that in the near future this behaviour would be the rule rather than the exception. The increase in salinity of surface waters could be of serious concern, especially for aquaculture, sensitive to sharp salinity increases.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265580

Monitoring nutrients fate after digestate spreading in a short rotation buffer area
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL
Autore/i: Colombani, Nicolò; Boz, Bruno; Gumiero, Bruna; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: One of the main sources of reactive nitrogen pollution is animal manure. The disposal of digestate (material remaining after the anaerobic digestion of a biodegradable feedstock) in agricultural soils could solve both the problems of soil fertilization and waste removal, but the fate of digestate in the environment must be assessed carefully before its massive utilization. To investigate whether digestate could be safely employed as a soil fertilizer, an agricultural field located in Monastier di Treviso (Northern Italy) and characterized by the presence of low hydraulic conductivity clay soils, was selected to be amended with bovine digestate. The experimental site was intensively monitored by a three-dimensional array of probes recording soil water content, temperature, and electrical conductivity, to solve the water and bulk mass fluxes in the unsaturated zone. High-resolution soil coring allowed the characterization of soil water composition over two hydrological years. Chloride, found in high concentrations in the digestate, was used as environmental tracer to track the fate of the percolating water. The study concluded that digestate could be confidently employed in short rotation buffer areas at an average rate of 195 ± 26 kg-N/ha/year in low hydraulic conductivity soils not affected by diffuse fracturing during dry periods.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265608

High resolution short-term investigation of soil CO2, N2O, NOx and NH3 emissions after different chabazite zeolite amendments
APPLIED SOIL ECOLOGY
Autore/i: Ferretti, Giacomo; Keiblinger, Katharina M.; Zimmermann, Michael; Di Giuseppe, Dario; Faccini, Barbara; Colombani, Nicolò; Mentler, Axel; Zechmeister-Boltenstern, Sophie; Coltorti, Massimo; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Reducing the effects of climate change is a key-point to achieve sustainable development. It is known that fertilizer application stimulates soil gaseous N losses, especially immediately after their application. In this short-term incubation experiment, the effects of different chabazite zeolite amendments on soil gaseous emissions (CO2, N2O, NOx and NH3) were evaluated in high resolution as potential mitigation strategy for agricultural soils. Different soil-zeolite mixtures, including both natural and NH4 +-enriched chabazite zeolites, were incubated for 24 h both immediately after the application of urea fertilizer and without a further N input in order to carry out a high resolution investigation of soil CO2, N2O, NOx and NH3 fluxes, in comparison to an unamended soil. Immediate CO2, N2O, NOx and especially NH3 emissions after fertilizer application were generally reduced in soils amended with zeolites at natural state, indicating a potential valuable material for reducing soil C-N gaseous losses. On the other hand, the application of NH4 +-enriched zeolites lowered CO2 and N2O emissions, but very high NOx fluxes occurred during the first 24 h even without applying any further N input. NH3 emissions were higher in NH4 +-enriched zeolites amended soil, but if the amendment is performed without further N inputs, the emissions can be significantly lowered with respect to a conventional urea fertilization.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265640

A modified SINTACS method for groundwater vulnerability and pollution risk assessment in highly anthropized regions based on NO3− and SO42− concentrations
SCIENCE OF THE TOTAL ENVIRONMENT
Autore/i: Busico, Gianluigi; Kazakis, Nerantzis; Colombani, Nicolò; Mastrocicco, Micòl; Voudouris, Konstantinos; Tedesco, Dario
Classificazione: 1 Contributo su Rivista
Abstract: Groundwater vulnerability and risk assessment area worldwide tools in supporting groundwater protection and land planning. In this study, we used three of these different methodologies applied to the Campanian Plain located in southern Italy: SINTACS, AVI and LOS. However, their capability to describe the observed chemical pollution of the area has resulted quite poor. For such a reason, a modified SINTACS method has been then implemented in the area in order to get a more reliable view of groundwater vulnerability. NO3 − and SO4 2 − from more than 400 monitoring wells were used for specific vulnerability assessment. Land use was chosen as key parameter to infer the risk of groundwater pollution in our area. The new methodology seems to show a higher correlation with observed NO3 − concentrations and a more reliable identification of aquifer's pollution hot spots. The main sources of NO3 − were found in sub-urban areas, where vulnerability and risk are higher than in other areas. Otherwise due to reducing conditions triggered by the presence of elevated sedimentary organic matter and peat, concentrations below agricultural areas were lower than in sub-urban areas. The SO4 2 − specific vulnerability map showed a positive correlation with observed concentrations, due to geogenic and anthropogenic SO4 2 − sources present in the area. The combination of both NO3 − and SO4 2 − derived risk maps becomes essential to improve the conceptual model of aquifer pollution in this severely anthropized area. The application of this new and original approach shed light on the strengths and weaknesses of each of the described previous methods and clearly showed how anthropogenic activities have to be taken into account in the assessment process.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265539

Chlorate origin and fate in shallow groundwater below agricultural landscapes
ENVIRONMENTAL POLLUTION
Autore/i: Mastrocicco, Micòl; Di Giuseppe, Dario; Vincenzi, Fabio; Colombani, Nicolò; Castaldelli, Giuseppe
Classificazione: 1 Contributo su Rivista
Abstract: In agricultural lowland landscapes, intensive agricultural is accompanied by a wide use of agrochemical application, like pesticides and fertilizers. The latter often causes serious environmental threats such as N compounds leaching and surface water eutrophication; additionally, since perchlorate can be present as impurities in many fertilizers, the potential presence of perchlorates and their by-products like chlorates and chlorites in shallow groundwater could be a reason of concern. In this light, the present manuscript reports the first temporal and spatial variation of chlorates, chlorites and major anions concentrations in the shallow unconfined aquifer belonging to Ferrara province (in the Po River plain). The study was made in 56 different locations to obtain insight on groundwater chemical composition and its sediment matrix interactions. During the monitoring period from 2010 to 2011, in June 2011 a nonpoint pollution of chlorates was found in the shallow unconfined aquifer belonging to Ferrara province. Detected chlorates concentrations ranged between 0.01 and 38 mg/l with an average value of 2.9 mg/l. Chlorates were found in 49 wells out of 56 and in all types of lithology constituting the shallow aquifer. Chlorates concentrations appeared to be linked to NO3 −, volatile fatty acids (VFA) and oxygen reduction potential (ORP) variations. Chlorates behaviour was related to the biodegradation of perchlorates, since perchlorates are favourable electron acceptors for the oxidation of labile dissolved organic carbon (DOC) in groundwater. Further studies must take into consideration to monitor ClO4 − in pore waters and groundwater to better elucidate the mass flux of ClO4 − in shallow aquifers belonging to agricultural landscapes. The main findings are the first recognition in Europe of ClO3 − temporal and spatial variation concentrations in a shallow unconfined aquifer belonging to agricultural landscapes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265541

Coastal aquifer response to extreme storm events in Emilia-Romagna, Italy
HYDROLOGICAL PROCESSES
Autore/i: Giambastiani, Beatrice M. S.; Colombani, Nicolò; Greggio, Nicolas; Antonellini, Marco; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: With global warming and sea level rise, many coastal systems will experience increased levels of inundation and storm flooding, especially along sandy lowland coastal areas, such as the Northern Adriatic coast (Italy). Understanding how extreme events may directly affect groundwater hydrology in shallow unconfined coastal aquifers is important to assess coastal vulnerability and quantify freshwater resources. This study investigates shallow coastal aquifer response to storm events. The transitory and permanent effects of storm waves are evaluated through the real time monitoring of groundwater and soil parameters, in order to characterize both the saturated and unsaturated portions of the coastal aquifer of Ravenna and Ferrara (southern Po Delta, Italy). Results highlight a general increase in hydraulic head and soil moisture, along with a decrease in groundwater salinity and pore water salinity due to rainfall infiltration during the 2 days storm event. The only exceptions are represented by the observation wells in proximity to the coastline (within 100 m), which recorded a temporary increase in soil and water salinity caused by the exceptional high waves, which persist on top of the dune crest during the storm event. This generates a saline plume that infiltrates through the vadose zone down to the saturated portion of the aquifer causing a temporary disappearance of the freshwater lens generally present, although limited in size, below the coastal dunes. Despite the high hydraulic conductivity, the aquifer system does not quickly recover the pre-storm equilibrium and the storm effects are evident in groundwater and soil parameters after 10 days past the storm overwash recess.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265774

Nitrogen and sulphur cycling in the saline coastal aquifer of Ferrara, Italy. A multi-isotope approach
APPLIED GEOCHEMISTRY
Autore/i: Caschetto, M.; Colombani, N.; Mastrocicco, M.; Petitta, M.; Aravena, R.
Classificazione: 1 Contributo su Rivista
Abstract: he origin of high ammonium and sulphate concentrations, characterizing the saline groundwater of the Po River floodplain coastal aquifer, are documented. A detailed understanding of the hydrogeochemical conceptual model is built up using a hydrochemical (major ions, DOC, DIC and methane) and isotopic (δ15NNO3, δ15NNH4, δ18ONO3, δ34SSO4, δ18OSO4 and δ13CDIC) approach. Based on previous hydrogeological investigations, two boreholes located in contrasting environments (urban and agricultural) have been sampled at high vertical resolution. Groundwater is mostly under reducing conditions, characterized by high DOC and DIC concentrations but low to moderate methane content. Dissolved ammonium, as high as 87.8 mgL−1, derives by the mineralization of N-organic rich fine sediments, as indicated by its N isotopic signatures (1÷3‰). Attenuation processes of ammonium are ruled by dilution and by partial nitrification, supported by the enrichment in δ15NNH4 (∼+7‰). Apart from dilution/oxidation processes, the positive correlation between δ15NNO3 and δ18ONO3 agreed with the occurrence of denitrification in the shallow part of the aquifer. δ34SSO4 and δ18OSO4 data highlight that oxidation of pyrite occurs but is not necessarily linked to nitrate removal. The isotope data showed that sulphate (>2500 mgL−1) is of marine origin. In the deeper part of the aquifer, sulphur and oxygen isotopes enrichment patterns, demonstrated that sulphate reduction (SR) occurs in the aquifer and it is also possible that SR occurred in the underlying clay units. δ13CDIC pattern toward depleted δ13CDIC values even as low as −40.4‰ documented the occurrence of SR mediated by organic carbon and SR coupled to oxidation of methane (AOM) are involved in the sulphur and carbon cycles. The present study shows the advantage of using stable isotopes complemented with geochemical data to characterize the solutes' origins, both natural and anthropogenic, and giving insights on biogeochemical transformations involving nitrogen, sulphur and carbon in coastal sediments.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265776

Origin and pattern of salinization in the Holocene aquifer of the southern Po Delta (NE Italy)
JOURNAL OF GEOCHEMICAL EXPLORATION
Autore/i: Colombani, N.; Cuoco, E.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: The origin and patterns of groundwater salinity of a shallow coastal aquifer pertaining to a reclaimed subsiding zone of the Po Delta are examined in this study. The aim is to identify the source of the hypersaline groundwater residing in the basal portion of the aquifer and to infer the mechanism of salinization of the remaining portion of the aquifer. To disentangle the possible sources of salinity the molar ratio of environmental tracers like Cl− and Br− were used in combination with the classical geochemical analyses of major and minor cations ratios. High-resolution multi-level sampling (MLS) allowed obtaining a robust and self-consistent hydrogeochemical database, which was statistically analysed via factor analysis and proved to be log-normally distributed. Thus, a common origin could be inferred for the elevated salinity that characterize most of the groundwater samples, this can be recognized in the organic rich fine-grained sediments, deposited in salty back barrier and marsh environments during the last transgression phase. This study proves that a detailed analysis of groundwater geochemistry can be considered a valuable tool to assess the origin of salinity in coastal Holocene aquifers, where the traditional conceptual model of a simple fresh/seawater interface may not be adequate.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265775

Lithological Influence and Human Impact on the Hydrochemistry of an Apennine Watershed (Southern Italy)
IOP Conference Series: Earth and Environmental Science
Autore/i: Colombani, Nicolò; Cuoco, Emilio; Busico, Gianluigi; Darrah, Thomas; Mastrocicco, Micòl; Tedesco, Dario
Editore: Institute of Physics Publishing
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This study focuses on chemical and physical parameters of the Calore Catchment (Italy), to identify the sources of surface and groundwater mineralization. The study also evaluates water quality variations due to potential anthropogenic contamination. The proposed approach is a suitable screening tool to gain information on upland catchment characterized by complex hydrogeological and structural settings.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265779

Scenario Modelling of Climate Change's Impact on Salinization of Coastal Water Resources in Reclaimed Lands
Procedia Engineering
Autore/i: Colombani, Nicolò; Mastrocicco, Micòl
Editore: Elsevier Ltd
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A numerical model accounting for variable density flow and transport was built up to quantify the actual and future (2050) salinization trends of a coastal aquifer in the Po delta (Northern Italy). SEAWAT 4.0 was employed to model the interaction between the surface drainage system and the underlying aquifer. PEST was employed for inverse parameter calibration using hydraulic heads and groundwater salinities as constraints. The calibrated model was used to predict the behavior of the coastal aquifer using a multiple scenario approach: increase in evapotranspiration induced by temperature increase; increase in the frequency of extreme high rainfall events; extreme drought conditions; and irrigation canals dewatering due to salinization of the Po River branches. For each scenario, two sub-scenarios were established to account for the projected local sea level rise. The first three scenarios have only minimal effects on the aquifer salinization, while the fourth forecasts a severe aquifer salinization due to enhanced upward fluxes of saline and hypersaline groundwater. The scenarios quantified the possible future salinization trends of groundwater and could be useful to identify adaptation strategies which allow to better manage water resources of this and similar areas. Results show that the Po delta will experience a significant salinization by 2050 and that the major cause is autonomous salinization via seepage of saline groundwater rather than enhanced salt-water intrusion due to sea level rise. The enhanced autonomous salinization will increase the salt export into the drainage canals that are also employed for irrigation, posing serious treats to the local flourishing agricultural economy.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265787

Estimated Water Savings in an Agricultural Field Amended With Natural Zeolites
ENVIRONMENTAL PROCESSES
Autore/i: Colombani, Nicolò; Di Giuseppe, Dario; Faccini, Barbara; Ferretti, Giacomo; Mastrocicco, Micòl; Coltorti, Massimo
Classificazione: 1 Contributo su Rivista
Abstract: Agricultural practices can jeopardize soil and water quality, thus mitigation measures to reduce nutrient loss and to protect water resources have to be implemented in order to ensure a sound environmental quality and, at the same time, a high crop yield. Natural zeolites have been tested as soil conditioner to diminish nutrient leaching and increase irrigation efficiency. In this study, an experimental site of 6 ha was monitored for two years to assess whether amending the soil with natural zeolite may induce a considerable impact on the water balance. Three control parcels were cultivated and irrigated according to the traditional way; two parcels were amended with coarse-grained natural zeolite at different zeolite/soil ratio (5 and 15 kg/m2) and two parcels were amended with fine-grained zeolite (7 and 10 kg/m2). Soil electrical conductivity, temperature and volumetric water content were continuously monitored via TDR probes at different depths. Climatic variables for water balance calculation were obtained by a meteorological station installed on-site. Continuous monitoring highlighted an increase of soil water availability in the amended parcels with respect to the control ones. The parcel amended with 10 kg/m2 of fine-grained natural zeolite showed an average water content always higher than the control ones, in the upper soil horizon. In addition, after intense rainfall, this parcel showed an increased field capacity and a reduced percolation towards the deeper soil horizon. Finally, the residual water content was improved by 1.2 ± 0.4 % throughout the summer droughts.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265781

Natural and anthropogenic variations in the Po river waters (northern Italy): insights from a multi-isotope approach
ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES
Autore/i: Marchina, Chiara; Bianchini, Gianluca; Knoeller, Kay; Natali, Claudio; Pennisi, Maddalena; Colombani, Nicolò
Classificazione: 1 Contributo su Rivista
Abstract: Po is the main Italian river and the δ18O and δ2H of its water reveal a similarity between the current meteoric fingerprint and that of the past represented by groundwater. As concerns the hydrochemisty, the Ca–HCO3 facies remained constant over the last 50 year, and only nitrate significantly increased from less than 1 mg/L to more than 10 mg/L in the 1980s, and then attenuated to a value of 9 mg/L. Coherently, δ13CDIC and δ34SSO4 are compatible with the weathering of the lithologies outcropping in the basin, while extremely variable δ15NNO3 indicates contribution from pollutants released by urban, agricultural and zootechnical activities. This suggests that although the origin of the main constituents of the Po river water is geogenic, anthropogenic contributions are locally significant. Noteworthy, the associated aquifers have the same nitrogen isotopic signature of the Po river, but are characterized by significantly higher NO– 3 concentration. This implies that aquifers’ pollution is not ascribed to inflow of current river water, and that the attenuation of the nitrogen load recorded in the river is not occurring in the aquifers, due to their longer water residence time and delayed recovery from anthropogenic contamination.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265777

Use of shallow groundwater temperature profiles to infer climate and land use change: interpretation and measurement challenges
HYDROLOGICAL PROCESSES
Autore/i: Colombani, Nicolò; Giambastiani, Beatrice Maria Sole; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Temperature is often used to infer the effect of land use and climate conditions on aquifers. Reliable data are needed to examine the temperature behaviour in the subsurface; thus, the use of robust acquisition techniques is unavoidable. Three temperature measurement techniques were applied to assess the sources of bias that could occur during temperature logging in a shallow Quaternary coastal aquifer in Ferrara (Northern Italy). Open borehole temperature logging, multilevel sampling straddle packers isolated temperature measurements within a flow cell above ground and multilevel sampling straddle packers isolated temperature measurements via an in-well level logger (MLS-IW) were compared for several coastal monitoring wells to gain insights on the limitations of each technique. Results show that the source of bias between the three applied techniques are different: (i) the open borehole temperature logging method tends to record heat convection through the open borehole and is not representative of the aquifer temperature distribution; (ii) the multilevel sampling straddle packers isolated temperature measurements within a flow cell above ground method is swayed by the air temperature and the heating of the submersible pump used to lift groundwater above ground; and (iii) the MLS-IW provides the most reliable vertical thermal profiling both in summer and winter, because groundwater temperature is directly measured at the selected monitoring depth. The implementation of a 1D flow model demonstrates that if precise temperature profiles are needed to infer the influence that land use and climate changes have on groundwater, the MLS-IW method is a reliable method that could be applied to existing monitoring wells.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265830

Trend of Heavy Metal Release According to Forecasted Climate Change in the Po Delta
ENVIRONMENTAL PROCESSES
Autore/i: Colombani, Nicolò; Dinelli, Enrico; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: The low-lying coastal areas, and especially the delta areas are prone to saltwater intrusion due to sea level rise, which may lead to a loss of ecosystem services brought about by salinization of already limited freshwater reserves. Despite the acknowledged importance of climate change impacts and land use practices on water resources availability, there is still a lack of studies on the issue of climate change induced alteration of water quality. To understand the hydrogeochemical processes occurring within the shallow groundwater system of the Po River delta (Italy), the contribution of local water-sediment interaction and the anthropogenic influence on groundwater quality were quantified. High-resolution multi-level sampling was used to capture chemical gradients within the aquifer. Data were employed to calibrate a density-dependent multicomponent reactive transport model implemented with PHT3D code along a flow line. The reactive network accounted for redox driven organic matter oxidation and cation exchange. Finally, a series of numerical scenarios were run following the projection of IPCC 2014 on sea level rise and climate change. Results of the predictive model highlight an increase of arsenic and lead in the shallow portion of the aquifer, drained by the reclamation network. The increase of heavy metals export toward surface waters could be of serious concern, since the drainage network operates also for irrigation purposes. Thus, the surface water quality could be negatively affected by climate change.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265780

Misleading reconstruction of seawater intrusion via integral depth sampling
JOURNAL OF HYDROLOGY
Autore/i: Colombani, N.; Volta, G.; Osti, A.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Saltwater intrusion in coastal aquifers is an urgent issue for the actual and future groundwater supply and a detailed characterization of groundwater quality with depth is a fundamental prerequisite to correctly distinguish salinization processes. In this study, interpolated Cl- maps of the Po River delta coastal aquifer (Italy), gained with Integrated Depth Sampling (IDS) and Multi-Level Sampling (MLS) techniques, are compared. The data set used to build up the IDS and MLS interpolated Cl- maps come from numerous monitoring campaigns on surface and ground waters, covering the time frame from 2010 to 2014. The IDS interpolated Cl- map recalls the phenomenon of actual seawater intrusion, with Cl- concentration never exceeding that of seawater and the absence of hypersaline groundwater all over the study area. On the contrary, in the MLS interpolated Cl- maps the lower portion of the unconfined aquifer presents hypersaline groundwater making it necessary to consider salinization processes other than actual seawater intrusion, like upward flux from a saline aquitard. Results demonstrate the obligation of using MLS in reconstructing a reliable representation of the distribution of salinity, especially in areas where the density contrast between fresh and saline groundwater is large. Implications of the reported field case are not limited to the local situation but have a wider significance, since the IDS technique is often employed in saltwater intrusion monitoring even in recent works, with detrimental effect on the sustainable water resource management of coastal aquifers.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265783

Estimating groundwater residence time and recharge patterns in a saline coastal aquifer
HYDROLOGICAL PROCESSES
Autore/i: Caschetto, M.; Colombani, N.; Mastrocicco, M.; Petitta, M.; Aravena, R.
Classificazione: 1 Contributo su Rivista
Abstract: A detailed study using environmental tracers such as chloride (Cl−) and tritium (3H), deuterium (2H) and oxygen (18O) isotopes was performed in an alluvial coastal aquifer in two contrasting environments (urban and agricultural). These environmental tracers combined with a high-resolution multi-level sampling approach were used to estimate groundwater residence time and recharge patterns and to validate the hydrogeochemical conceptual model already proposed in previous studies. δ18O and δ2H combined with Cl− data proved that the hypersaline groundwater present in the deepest part of the aquifer was sourced from the underlying hypersaline aquitard via an upward flux. Both chemical and isotopic data were employed to calibrate a density-dependent numerical model based on SEAWAT 4.0, where 3H and Cl− were helped quantifying solutes transport within the modelled aquifer. Model results highlighted the differences on estimated recharge in the two contrasting environments, with the urban one exhibiting concentrated recharge because of preferential infiltration associated to the storm water drains network, while scarce local recharge characterized the agriculture setting. In the urban field site, is still possible to recognize at 9 m b.g.l. the input of the atmospheric anthropogenic 3H generated by testing of thermonuclear weapons, while in the agricultural field site, the 3H peak has been washed out at 6 m b.g.l. because the groundwater circulation is restricted only to the upper fresh part of the aquifer, drained by the reclamation system. The presented approach that combined high-resolution field monitoring, environmental tracers and numerical modelling, resulted effective in validating the conceptual model of the aquifer salinization.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265778

Formation and dissolution of salt crusts as a rapid way of nitrate mobilization in a tile-drained agricultural field under a temperate climate
ARABIAN JOURNAL OF GEOSCIENCES
Autore/i: Colombani, Nicolò; Di Giuseppe, Dario; Faccini, Barbara; Mastrocicco, Micòl; Coltorti, Massimo
Classificazione: 1 Contributo su Rivista
Abstract: Agriculture is widely recognized as one of the human activities that have a major impact on the pollution of water resources. In agricultural fields, the formation of salt crusts during dry periods and their fast dissolution due to irrigation or rainfall events can induce the leaching of water with an elevated content of dissolved species towards surface and ground waters. This process is rather common in arid environments but it also occurs in coastal plains in temperate environments. The formation of salt crusts was studied in a 6.3-ha experimental site located in the Po River Delta (Northern Italy). The soil, consisting of interfluvial silty-clay deposits recently reclaimed and equipped with tile drains to avoid water-logging conditions, was investigated for vertical spatial heterogeneity via depth profiles and for horizontal spatial heterogeneity collecting numerous surface soil samples. Extreme drought conditions were recorded over the monitoring period (summer–autumn 2012), leading to soil fracturing and then to fast water percolation during the first rainfall events in autumn. Major ion concentration, measured in pore-water, showed nitrate peaks of several grams per litre, suggesting the dissolution of nitrate salts. Results from this study highlighted the following: (i) that the fertilizers applied to the filed site were evapoconcentrated in the top soil; (ii) a marked spatial heterogeneity in the salt crust formation, which was unevenly distributed over the field with a preferential appearance in the hollows; and (iii) a rapid mobilization of nitrate towards tile drains after the first rainfall events, due to preferential flow through soil cracks developed during the summer season.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265784

Managed aquifer recharge via infiltration ditches in short rotation afforested areas
ECOHYDROLOGY
Autore/i: Mastrocicco, M.; Colombani, N.; Salemi, E.; Boz, B.; Gumiero, B.
Classificazione: 1 Contributo su Rivista
Abstract: Managed aquifer recharge design and operation must incorporate the expected long-term performance from a water quantity perspective to sustainably mitigate hydrologic impacts of groundwater overexploitation. Gravity-driven infiltration ditches in forested areas are one of many managed aquifer recharge schemes that could augment the available water resources. Research on the longevity of these structures is sparse, leading to concerns about their long-term capability to sustain elevated infiltration capacity. In the present study, an infiltration system consisting of a regular grid of eight ditches divided into four sequential plots within a short rotation forested area [area of infiltration (AFI)] was monitored from its inception to determine its hydrologic performance over time and its possible export to similar areas of the Brenta megafan (Northern Italy). During the monitored period, the AFI was not significantly affected by clogging because the suspended solids carried by the Brenta River water diversion were extremely low. The main source of clogging was the fallen foliage during the autumn, easily managed via ordinary maintenance. The AFI displayed an almost constant performance to infiltrate the diverted water over the first 3 years of operation, with a total amount of infiltrated water of approximately 0.8 Mm3ha-1year-1. The best tracer to reconstruct the downward water movement through this highly permeable vadose zone was temperature, while the groundwater table fluctuation could not be confidently used to infer the effective infiltration, because of its large seasonal variability. The good results suggest promoting this technique in other areas of the Brenta megafan that suffer from groundwater resources depletion.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265788

Impact of Climate Change on Salinization of Coastal Water Resources
WATER RESOURCES MANAGEMENT
Autore/i: Colombani, N.; Osti, A.; Volta, G.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: A density-dependent numerical model was set up to quantify the actual and future (2050) salinization of a coastal aquifer in the Po Delta (Italy). SEAWAT 4.0 was used for this purpose, while PEST was used for automatic inverse parameter calibration. The use of high-resolution multi-level sampling allowed obtaining insights in the salinity stratification within the aquifer and on the vertical fluxes induced by the reclamation drainage network. The calibrated model was employed to build up a scenario investigating the effects of the projected relative sea level rise on groundwater salinity by 2050. This scenario allowed to identify the zones that resulted more affected by the relative sea level rise and to quantify the increase in salinization of groundwater, the salt loads export towards surface waters and the changing volumes of freshwater. Results show that the Po Delta will experience a significant salinization by 2050 and that the major cause is autonomous salinization via seepage of saline groundwater rather than enhanced seawater intrusion due to sea level rise.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265782

Abnormal trace element concentrations in a shallow aquifer belonging to saline reclaimed environments, Codigoro (Italy)
ATTI DELLA ACCADEMIA NAZIONALE DEI LINCEI. RENDICONTI LINCEI. SCIENZE FISICHE E NATURALI
Autore/i: Mastrocicco, Micòl; Colombani, Nicolò; Di Giuseppe, Dario; Faccini, Barbara; Ferretti, Giacomo; Coltorti, Massimo
Classificazione: 1 Contributo su Rivista
Abstract: Geogenic trace element (TE) contamination is an upcoming concern. The present study reports the temporal and spatial variation of major ions and TEs in a shallow unconfined aquifer belonging to a complex marsh saline environment reclaimed in modern age and intensively cultivated. The use of intensive depth profiles in five different locations gave insights into groundwater and sediment matrix interactions. Data indicate that the dominant factor involved in determining the spatial variability of TE is the sediment–water interaction, while the temporal variation of TE is due to the organic matter content and to the water table oscillation, which in turn drive the groundwater redox status and the mobilization of some inorganic microconstituents, such as Fe and Mn. Despite that the anthropogenic input of TEs in groundwater from fertilizer sources cannot be undoubtedly ruled out, given the elevated TE background concentrations, the combined use of high-resolution sediment profiles, seasonal groundwater sampling and end-member analyses is a promising procedure to distinguish between anthropogenic metal contamination and geogenic contribution in reclaimed deltaic environments. Finally, this study underlines the need of having a dense piezometer network and to perform several monitoring campaigns to ensure that the temporal and spatial variability could be correctly represented and background values of TE confidently determined.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/265785

Detecting small-scale variability of trace elements in a shallow aquifer
WATER AIR AND SOIL POLLUTION
Autore/i: Giambastiani, Beatrice M. S.; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Groundwater samples collected from an unconfined shallow aquifer were analysed for major and trace element (TE) concentrations with the aim to investigate small-scale variations possibly linked to fertilizer residual products applied until 2004. The field site, located near Ferrara (Northern Italy), covers an area of 200 m2 and was a former agricultural field then converted into a park and equipped with a grid of 13 monitoring wells. Three monitoring campaigns were carried out in June 2007, March and June 2009 in order to detect spatial and temporal variations in water quality. Groundwater nitrate, chloride, bromide and sulphate concentrations decreased with time indicating that the fertilizer plume was slowly replaced by unpolluted groundwater. However, the groundwater composition showed values of TEs (Fe, Mn, Al, As and Hg) above the recommended international and national guideline values. Dissolved TE concentrations varied randomly in the three campaigns, while TEs in the solid matrix did not show particular enrichment factors induced by fertilizer use. The data indicated that the dominant factor involved in determining small-scale spatial variability of TE concentrations in this shallow aquifer was the sediment-water interaction, while the temporal variation of TEs was driven by the organic matter leaching from the topsoil and by water table oscillations, which in turn drove the groundwater redox status. This study emphasizes the need of small-scale TE spatial resolution to discriminate between anthropogenic non-point sources of pollution (like fertilizers) and background concentrations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266358

Batch and column experiments on nutrient leaching in soils amended with Italian natural zeolitites
CATENA
Autore/i: Colombani, N.; Mastrocicco, M.; Di Giuseppe, D.; Faccini, B.; Coltorti, M.
Classificazione: 1 Contributo su Rivista
Abstract: This paper describes the application of the Italian chabazite-rich tuff of Sorano (Grosseto) as a soil conditioner and slow nutrient fertilizer to a silty-clay soil and a sandy soil. The study was developed by means of batch and column experiments. The objectives of the study were: (1) to evaluate and compare the physical and hydraulic properties of mixtures of soil and natural zeolitite (95:5% v/v) with those of unamended soils, (2) to determine the effects of applying NH4+-enriched zeolitites on soils and (3) to model water and solutes movement in two different scenarios, with and without amendment incorporation. Results of column experiments were then modelled to obtain the physical-chemical and hydraulic parameters representative of the soils amended with the NH4+-enriched zeolitites. Using synthetic rainwater as eluent, NH4+ was never detected in the water phase of batches and columns; NO3- and PO43- were both present at high concentrations in batch tests and were leached in column elution tests. NO3- displayed very high concentrations at the beginning of the elution whereas PO43- showed low concentrations and retarded peaks in both amended soil columns. The rationale of the study lies in the belief that inorganic amendments, which improve the physical and hydraulic properties of soils, can lead to minimized leaching of nutrients.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266352

Preliminary assessment on flood mitigation potential via manage aquifer recharge in the Brenta Megafan (Italy)
RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA
Autore/i: Mastrocicco, Micól; Colombani, Nicoló; Boz, Bruno; Gumiero, Bruna
Classificazione: 1 Contributo su Rivista
Abstract: Managed aquifer recharge (MAR) design and operation must incorporate the expected long-term performance from a water quantity perspective to sustainably mitigate hydrologic impacts of groundwater overexploitation. Gravity driven infiltration ditches are one of many MAR schemes that could augment the available water resources. In the present study, an infiltration system (IS) consisting of 8 ditches was monitored to determine its hydrologic performance over time and its possible export to similar areas of the Brenta Megafan (Northern Italy). The IS displayed an almost constant capacity to infiltrate the diverted water with a total amount of 0.8 Mm3/ha/y. The good results suggest to promote this technique in other areas that suffer from groundwater resources depletion.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266360

Seismic induced variation of hydraulic conductivity distribution in a large tank
RENDICONTI ONLINE DELLA SOCIETÀ GEOLOGICA ITALIANA
Autore/i: Colombani, Nicoló; Mastrocicco, Micól; Salemi, Enzo
Classificazione: 1 Contributo su Rivista
Abstract: A large tank (4x8x1.4 m) equipped with 26 standard piezometers and filled with sandy sediments (35 m3), was characterized via slug tests and grain size distribution analysis in 2006. The characterization via slug tests was repeated in 2013 after the seismic events of May 2012 near Ferrara (IT) characterized by a maximum Mw of 5.9 to infer the hydrological response of the tank's hydraulic conductivity field to the stresses induced by the earthquake. Results show a general decrease in hydraulic conductivity values, due to compaction phenomena, and a variation in the spatial distribution of hydraulic conductivity values, directly correlated to the presence of the finer fraction of the sediments within the large tank. In particular, the lenses, prevalently made of sandy sediments showed a negligible reduction, while the lenses constituted prevalently by silt displayed a larger decrease. The differential hydraulic conductivity reduction inhibited the flow linkages between the sandy lenses, provoking a four times decrease in the bulk hydraulic conductivity of the tank. This laboratory experiment highlights that pronounced hydraulic conductivity shrinkages should be expected after important seismic events in heterogeneous fine alluvial units.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266357

Predicting Salinization Trends in a Lowland Coastal Aquifer: Comacchio (Italy)
WATER RESOURCES MANAGEMENT
Autore/i: Colombani, Nicolò; Mastrocicco, Micòl; Giambastiani, Beatrice Maria Sole
Classificazione: 1 Contributo su Rivista
Abstract: The coastal aquifer salinization is an urgent problem caused by groundwater resources overexploitation and climate change. This phenomenon is enhanced in areas lying below the sea level, like the polders in the Netherlands or the Po River lowland in Italy. In these reclaimed lands the saltwater intrusion is usually controlled by a network of irrigation canals that supplies freshwater to the shallow aquifer, maintaining soil salinity at acceptable levels. The 2012 was dramatic in terms of agricultural water supply, since the Po River plain experienced a prolonged drought. Despite this, continuous monitoring of piezometric heads and total dissolved solids (TDS) near a canal (Canale della Gronda) demonstrated that freshening was occurring in the shallow portion (first 4 m) of the unconfined aquifer, while the bottom part was characterized by elevated relic salinity. The two-dimensional model SEAWAT was calibrated using piezometric heads and TDS depth profiles measured along a transect perpendicular to the canal. The calibrated model was then used to predict the behaviour of this cross section using a multiple scenario approach: increase in evapotranspiration induced by temperature increase; increase in the frequency of extreme high rainfall events; extreme drought conditions; and canal dewatering due to salinization of the water courses. Moreover, for each scenario, two sub-scenarios were run to account for projected sea level rise. The first three scenarios had only a minor influence on the aquifer salinization rate, while the fourth one predicted serious upward flux of the high salinity groundwater actually residing in the bottom of the unconfined aquifer. The scenarios quantified the possible future effects on groundwater salinization and could be useful to find adaptation strategies to manage the water resources of this and similar areas.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266359

Comparison of Different “S-index” Expressions to Evaluate the State of Physical Soil Properties
GEOTECHNICAL AND GEOLOGICAL ENGINEERING
Autore/i: Aschonitis, V. G.; Salemi, E.; Colombani, N.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: The S-index describes the absolute value of slope at the inflection point of the water retention curve (WRC) and it is a popular tool for the indirect description of the soil physical-hydraulic conditions. It can be calculated as a function of van Genuchten (VG) parameters by four different expressions based on (a) the use of arithmetic or ln-transformed axis of pressure head h and (b) the use of volumetric θ or gravimetric W soil water content [the four expressions are obtained from the dθ/dh, dW/dh, dθ/d(lnh) and dW/d(lnh) derivatives]. The aim of the study is to test the ability of the four S-index expressions to rank soil physical-hydraulic (SPH) indicators such as fractions of porosity, bulk density and saturated hydraulic conductivity. WRCs of an artificial soil, which was subjected to flooding and extensive destruction of macroporosity, and WRCs from the twelve USDA soil classes were used in the analysis. The results showed that the expressions of dθ/dh and dW/dh display higher correlations versus the SPH indicators in comparison to dθ/d(lnh) and dW/d(lnh). The expressions based on the gravimetric approach such as dW/dh and dW/d(lnh) do not contain the parameter of bulk density while the expressions based on the ln-transformed axis of h do not contain the parameter a of VG model. Even though dθ/dh and dW/dh showed similar performance, the first one is suggested as the safest approach to describe SPH indicators for non-deformable soils because its theoretical background is more consistent and more relevant to porosity attributes which are always described in terms of volume and not of mass, whereas the second one is suggested for the case of deformable soils in order to avoid errors introduced by the changes of bulk density.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266345

Combined use of heat and saline tracer to estimate aquifer properties in a forced gradient test
JOURNAL OF HYDROLOGY
Autore/i: Colombani, N.; Giambastiani, B. M. S.; Mastrocicco, M.
Classificazione: 1 Contributo su Rivista
Abstract: Usually electrolytic tracers are employed for subsurface characterization, but the interpretation of tracer test data collected by low cost techniques, such as electrical conductivity logging, can be biased by cation exchange reactions. To characterize the aquifer transport properties a saline and heat forced gradient test was employed. The field site, located near Ferrara (Northern Italy), is a well characterized site, which covers an area of 200 m2 and is equipped with a grid of 13 monitoring wells. A two-well (injection and pumping) system was employed to perform the forced gradient test and a straddle packer was installed in the injection well to avoid in-well artificial mixing. The contemporary continuous monitor of hydraulic head, electrical conductivity and temperature within the wells permitted to obtain a robust dataset, which was then used to accurately simulate injection conditions, to calibrate a 3D transient flow and transport model and to obtain aquifer properties at small scale. The transient groundwater flow and solute-heat transport model was built using SEAWAT. The result significance was further investigated by comparing the results with already published column experiments and a natural gradient tracer test performed in the same field. The test procedure shown here can provide a fast and low cost technique to characterize coarse grain aquifer properties, although some limitations can be highlighted, such as the small value of the dispersion coefficient compared to values obtained by natural gradient tracer test, or the fast depletion of heat signal due to high thermal diffusivity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266356

Revisiting the Priestley-Taylor method for the assessment of reference crop evapotranspiration in Italy
ITALIAN JOURNAL OF AGROMETEOROLOGY
Autore/i: Aschonitis, Vassilis; Demertzi, Kleoniki; Papamichail, Dimitris; Colombani, Nicolò; Mastrocicco, Micòl
Classificazione: 1 Contributo su Rivista
Abstract: Aim of the study is to test the Priestley-Taylor (P-T) method for the assessment of reference crop evapotranspiration ETo in the Italian territory using as a base the ASCE standardized Penman-Monteith method (ASCE). Monthly averages of daily mean climatic data which cover the period 1950-2000 were used in this study. Analysis was performed on the spatial variability of the seasonal difference between ASCE and P-T method using the typical value 1.26 for the advection coefficient apt. The results showed that the surface coverage of the Italian territory, with acceptable ±10% difference using apt=1.26, was 24.9% in Spring, 41.4% in Summer, 34.3% in Autumn and 11.9% in Winter. The recalculation of apt using the ASCE method showed high spatial and temporal variability of the coefficient. Regression analysis showed that more than 90% of the spatial variability of the seasonal apt is explained by the spatial variability of vapour pressure deficit DE (positive correlation). The rate of apt variation per unit DE was found significantly different between seasons and it was negatively correlated to net solar radiation Rn and consequently temperature. The general trends of the apt coefficient led to the conclusion that colder-drier environments due to low net radiation and high vapour pressure deficit tend to increase its values.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266361

Fate of arsenic, phosphate and ammonium plumes in a coastal aquifer affected by saltwater intrusion
JOURNAL OF CONTAMINANT HYDROLOGY
Autore/i: Colombani, N.; Mastrocicco, M.; Prommer, H.; Sbarbati, C.; Petitta, M.
Classificazione: 1 Contributo su Rivista
Abstract: A severe groundwater contamination with extensive plumes of arsenic, phosphate and ammonium was found in a coastal aquifer beneath a former fertilizer production plant. The implementation of an active groundwater remediation strategy, based on a comprehensive pump and treat scheme, now prevents the migration of the dissolved contaminants into the marine environment. However, due to the site's proximity to the coastline, a seawater wedge was induced by the pumping scheme. Additionally the groundwater flow and salinity patterns were also strongly affected by leakage from the site's sewer system and from a seawater-fed cooling canal. The objective of this study was to elucidate the fate of arsenic and its co-contaminants over the site's history under the complex, coupled hydrodynamic and geochemical conditions that prevail at the site. A detailed geochemical characterisation of samples from sediment cores and hydrochemical data provided valuable high-resolution information. The obtained data were used to develop various conceptual models and to constrain the development and calibration of a reactive transport model. The reactive transport simulations were performed for a sub-domain (two-dimensional transect) of an earlier developed three-dimensional flow and variable density solute transport model. The results suggest that in the upper sub-oxic zone the influx of oxygenated water promoted As attenuation via co-precipitation with Al and Fe oxides and copper hydroxides. In contrast, in the deeper aquifer zone, iron reduction, associated with the release of adsorbed As and the dissolution of As bearing phases, provided and still provides to date a persistent source for groundwater pollution. The presented monitoring and modelling approach could be broadly applied to coastal polluted sites by complex contaminant mixture containing As.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266347

Performance of different assessment methods to evaluate contaminant sources and fate in a coastal aquifer
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL
Autore/i: Sbarbati, C.; Colombani, N.; Mastrocicco, M.; Aravena, R.; Petitta, M.
Classificazione: 1 Contributo su Rivista
Abstract: The present study deals with the application of different monitoring techniques and numerical models to characterize coastal aquifers affected by multiple sources of contamination. Specifically, equivalent freshwater heads in 243 monitoring wells were used to reconstruct the piezometric map of the studied aquifer; flow meter tests were carried out to infer vertical groundwater fluxes at selected wells; deuterium and oxygen isotopes were used to identify the groundwater origin, and tritium was analyzed to estimate the residence time; compound-specific isotope analyses and microbial analyses were employed to track different sources of contamination and their degradation; numerical modelling was used to estimate and verify groundwater flow direction and magnitude throughout the aquifer. The comparison of the information level for each technique allowed determining which of the applied approaches showed the best results to locate the possible sources and better understanding of the fate of the contaminants. This study reports a detailed site characterization process and outcomes for a coastal industrial site, where a comprehensive conceptual model of pollution and seawater intrusion has been built using different assessment methods. Information and results from this study encourages combining different methods for the design and implementation of the monitoring activities in real-life coastal contaminated sites in order to develop an appropriate strategy for control and remediation of the contamination.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266335

Trace elements mobility in a saline coastal aquifer of the Po river lowland (Italy)
JOURNAL OF GEOCHEMICAL EXPLORATION
Autore/i: Colombani, Nicolò; Mastrocicco, Micòl; Dinelli, Enrico
Classificazione: 1 Contributo su Rivista
Abstract: The effect of elevated salinity (> 50 g/l) on the mobility of trace elements (Br, Sc, Ti, Cr, Ni, Co, As, Cd, Pb and Zn) was studied, within a shallow coastal aquifer. The use of intensive depth profiles with resolution of 0.5. m in two different locations, gave insight into groundwater and sediment matrix interaction. The collected sediments were analyzed for major and trace elements via XRF powder pellets, while major ions in groundwater were analyzed via IC and trace elements via ICP-MS.The total concentration of trace elements within the aquifer matrix was higher in the fine sediments, since usually these elements concentrate in the clay fraction, while the concentration in groundwater generally increased with the ionic strength of the solution. The increase of salinity in conjunction with a high content in carbonates stimulated a release of Pb and Zn, suggesting surface complexation on carbonate and dolomite minerals. The elevated organic carbon content of the sediments induced reducing conditions throughout the aquifer, which further promoted trace elements dissolution. The only exceptions were V and As that did not followed this trend, most probably released by peaty layers and fertilizers leaching.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266353

The Po river water from the Alps to the Adriatic Sea (Italy): new insights from geochemical and isotopic (δ18O-δD) data
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL
Autore/i: Marchina, Chiara; Bianchini, Gianluca; Natali, Claudio; Pennisi, Maddalena; Colombani, Nicolò; Tassinari, Renzo; Knoeller, Kay
Classificazione: 1 Contributo su Rivista
Abstract: Although the Po river is the most important fluvial system of Northern Italy, the systematic geochemical and isotopic investigations of its water are rare and were never reported for the whole basin. The present contribution aims to fill this knowledge gap, reporting a comprehensive data set including oxygen and hydrogen stable isotopes as well as major and trace element concentration of dissolved species for 54 Po river water samples, mainly collected in different hydrological conditions (peak discharge in April, drought in August) at increasing distance from the source, i.e., from the upper part of the catchment to the terminal (deltaic) part of the river at the confluence with the Adriatic Sea. The isotopic compositions demonstrate that the predominant part of the runoff derives from the Alpine sector of the catchment through important tributaries such as the Dora Baltea, Ticino, Adda, and Tanaro rivers, whereas the contribution from the Apennines tributaries is less important. The geochemical and isotopic compositions show that the Po river water attains a homogeneous composition at ca. 100 km from the source. The average composition is characterized by δ18O −9.8 ‰, δD −66.2 ‰, total dissolved solid (TDS) 268 mg/L, and chloride 17 mg/L and by a general Ca–HCO3 hydrochemical facies, which is maintained for most of the river stream, only varying in the terminal part where the river is diverted in a complex deltaic system affected by more significant evaporation and mixing with saline water evidenced by higher TDS and chloride content (up to 8198 and 4197 mg/L, respectively). Geochemical and isotopic maps have been drawn to visualize spatial gradients, which reflect the evolution of the river water composition at progressive distance from the source; more detailed maps were focused on the deltaic part in order to visualize the processes occurring in the transitional zone toward the Adriatic Sea. The data also highlight anthropogenic contributions, mainly represented by significant concentrations of nitrate (average 8 mg/L) and possibly arsenic (average 12 μg/L). These data allow the calculation of geochemical fluxes transferred from the river to the sea, and generally, they contribute to the definition of a “hydro-archive” which is useful to highlight ongoing variations in the related ecosystems.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266362

Modelling groundwater residence time in a sub-irrigated buffer zone
ECOHYDROLOGY
Autore/i: Mastrocicco, M.; Boz, B.; Colombani, N.; Carrer, G. M.; Bonato, M.; Gumiero, B.
Classificazione: 1 Contributo su Rivista
Abstract: This study focuses on the short groundwater residence time induced by the development of a dense rooting system in a forested area employed as a buffer zone planned for nitrogen removal. The buffer zone consists of a rectangular area of 0 center dot 7ha sub-irrigated by two ditches and drained by an outflow ditch lying in the centre of the area. The pristine soil (silty clay loam) was characterized by a low hydraulic conductivity, but the agricultural practice first, and then the rooting system increased the permeability of the top soil. This was confirmed by the elevated discharge in the outflow ditch and by the elevated hydraulic conductivity values determined via slug tests. The groundwater residence time was monitored, once the rooting system was completely developed, via Rhodamine-WT injection in the inflow ditch. The breakthrough curves were simulated using a one-dimensional analytical model (CXTFIT) to calculate the residence time. In addition, a three-dimensional flow and transport model (MODFLOW and MT3DMS) was calibrated using piezometric heads, groundwater fluxes and Rhodamine-WT concentrations. The CXTFIT model overestimated the dispersivity and underestimated velocity respect to MT3DMS. This study shows that residence time can decrease respect to the value expected from the hydraulic conductivities of the pristine soils and that one-dimensional analytical models can give a false impression compared with soil parameters respect to three-dimensional flow and transport models. Given the importance of the residence time for biological processes in buffer zones, a greater effort is needed to improve measurement techniques on subsurface flow's heterogeneity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266707

The influence of disaggregation procedures on soil gravitational separation
APPLIED CLAY SCIENCE
Autore/i: Salemi, Enzo; Tessari, Umberto; Colombani, Nicolò; Mastrocicco, Micol
Classificazione: 1 Contributo su Rivista
Abstract: The use of dispersants in particle size analysis is a common practice, but this could cause bias on the gravitational separation of the different particle fractions in natural soil. The study highlights the results obtained in gravitational separation of silty and clayey fractions by using hydrogen peroxide (H2O2) and sodium hexametaphosphate ((NaPO3)6) in different combinations. The efficiency of the different treatments was verified by comparison against the results obtained on the same sediments without any treatment. The separation method is based on Stokes law to calculate the settling time of particles in deionized water under controlled temperature. This method was applied to three different agricultural soils of the Po River Plain. The sample treated with H2O2 and (NaPO3)6 at 4% showed the best results in terms of particle size degree of purity, ranging from 95% to 97% for clay and from 91% to 95% for silt. The degree of purity indicates the percentage of sediment with the particles of the provided grain sizes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266383

Reclamation influence and background geochemistry of neutral saline soils in the Po River Delta Plain (Northern Italy)
ENVIRONMENTAL EARTH SCIENCES
Autore/i: Di Giuseppe, Dario; Faccini, Barbara; Mastrocicco, Micòl; Colombani, Nicolò; Coltorti, Massimo
Classificazione: 1 Contributo su Rivista
Abstract: Reclaimed neutral saline sulphate soils constitute a large part of the eastern part of Po Plain lowlands, where intensive agricultural activities take place. The knowledge of their geochemical features is essential to develop the best management practices capable to preserve this threatened environment. With this aim, three boreholes were drilled in an agricultural field and a typical reclaimed soil profile has been characterized for major and trace element, pH, electrical conductivity, redox conditions and water-soluble anions and ammonium. Statistical analysis (cluster analysis and principal component analysis) has been used to understand the relationship between elements and grain size. The soil profile is characterized by high salinity and high organic matter contents responsible for high chloride, sulphate, and ammonium concentrations. Heavy metal content is naturally high, since Po Plain sediments are the result of ultramafic rocks erosion; in addition, organic matter tends to concentrate heavy metals by adsorption, mainly in peaty horizons. As a consequence of chemical and zootechnical fertilization, high NO3 − contents have been found in the top soil, thus enhancing the risk of nitrate discharge in the water system, especially in relation to extreme climatic events.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266386

Variation of the hydraulic properties and solute transport mechanisms in a silty-clay soil amended with natural zeolites
CATENA
Autore/i: Colombani, N.; Mastrocicco, M.; Di Giuseppe, D.; Faccini, B.; Coltorti, M.
Classificazione: 1 Contributo su Rivista
Abstract: This study aims to quantify changes in flow and transport parameters induced by the addition of zeolites in a silty-clay soil. Hydraulic and physical processes governing solute transport under variably saturated flow conditions were studied in a laboratory scale analog model (AM) irrigated with canal water for seven weeks. One plot of the AM was fertilized with 270kg-N/ha of urea while the other plot was amended with 5kg/m2 of NH4 +-enriched chabazite. The observed water flow was inversely simulated using the single porosity (SP) and the dual porosity (DP) approaches; solute transport was inversely simulated using the convection-dispersion equation (CDE) and the mobile-immobile (MIM) approaches using HYDRUS-1D. Total domain reflectometry (TDR) probes were used to track soil water content and salinity while moisture sensors allowed obtaining the matric potential. The transport of bulk solutes through the soil could be coherently described using a simple approach (SP+CDE). Inverse parameter estimation suggested that percolation and solute front can be confidently predicted in silty-clay soils in case of low precipitation intensity using a combination of TDR and matric potential monitoring techniques. This study shows that NH4 +-enriched zeolites increase the water retention capacity even in silty-clay soils, thus limiting water and solute losses.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/266385