12 research outputs found

    Actual and forecasted vulnerability assessment to seawater intrusion via galdit-susi in the volturno river mouth (Italy)

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    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

    INVESTIGATION OF THE QUANTITATIVE AND QUALITATIVE STATUS OF COASTAL AQUIFER IN KALLIKRATIA-FLOGITA, CHALKIDIKI, GREECE

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    Σκοπός της παρούσας εργασίας αποτελεί η διερεύνηση της ποσοτικής και ποιοτικής κατάστασης του παράκτιου υδροφορέα στην περιοχή Καλλικράτειας–Φλογητών. Για την υλοποίηση της, αξιοποιήθηκαν υδροχημικά και κλιματικά δεδομένα, καθώς και μετρήσεις στάθμης του υπόγειου νερού. Η συνεχής πτώση της στάθμης του υπόγειου νερού, με ρυθμό 0,76 m/έτος, στην περιοχή έρευνας έχει συντελέσει στην υφαλμύριση αφενός εξαιτίας της διείσδυσης του θαλασσινού νερού, αφετέρου στην ανάμειξη γεωθερμικών ρευστών με τους ψυχρότερους επιφανειακούς υδροφορείς. Επιπλέον πίεση μπορεί να θεωρηθεί η νιτρορύπανση του υπόγειου νερού λόγω της εντατικής χρήσης λιπασμάτων. Συμπερασματικά, διαπιστώνεται πως η κακή διαχείριση του υπόγειου νερού αποτελεί τη σημαντικότερη αιτία για την ποσοτική μείωση και ποιοτική υποβάθμιση του υπόγειου νερού έναντι των αναφερόμενων κλιματικών μεταβολών/αλλαγών. Η ποσοτικοποίηση της συνεισφοράς των δύο κυρίαρχων αιτιών της υποβάθμισης του υπόγειου νερού χρήζει περαιτέρω έρευνας. The aim of this study was the determination of quantitative and qualitative status of the coastal aquifer in Kallikratia-Flogita area (Chalkidiki, North Greece). Hence, the hydrochemical data, water level measurements and climatic data were elaborated and evaluated. Groundwater decline occur with a mean rate up to 0.76 m/year which has led to salinization of the aquifer due to seawater intrusion and mixing of geothermal fluids with the upper fresh aquifers. Nitrate pollution is a further stressor that is attributed to fertilizers. Mismanagement of groundwater is the dominant cause of groundwater deterioration, while the referred climate changes follows. Quantification of the two stressors requires further and deeper analysis

    The implications of Brexit for environmental law in Scotland

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    This report maps the possible implications of Brexit for environmental protection in Scotland, identifying core questions as well as solutions that may be adopted, with the objective of initiating a conversation about this complex subject matter. The report has been prepared as a joint endeavour by a group of environmental law experts based at Scottish Universities. Each section was drafted by a lead author, with inputs from the rest of the group. The paper is meant for a broad audience and intentionally uses a non-technical writing style. The paper is divided in two sections. The first section addresses cross-cutting questions affecting environmental governance after Brexit, focusing on the main Brexit scenarios and their trade, competition, and law enforcement implications. This analysis identifies a series of common challenges for nvironmental law in Scotland after Brexit, which relate to: •Loss of scrutiny and enforcement powers associated with the operation of EU law and institutions; •Loss of long-term policy horizon and of the stable regulatory framework provided by EU law; •Repositioning of the UK and Scotland in international and regional environmental governance cooperation; and •Restriction/loss of access to EU funds and programmes. The second section analyses specific questions likely to emerge in elected areas of environmental law, distinguishing between different types of EU environmental legislation and the related allocation of competences within the UK. The transposition of EU environmental law into domestic law takes place in different ways. Some pieces of EU environmental law have been transposed into UK/Scottish law and configure distinctively UK/Scottish solutions. After Brexit, retaining these pieces of legislation is going to be relatively straightforward. Other pieces of EU environmental law, conversely, heavily rely upon EU processes and institutions and will no longer be applicable in their present form after Brexit. On these matters, EU powers and competences will be repatriated, raising fundamental questions concerning the allocation of powers between the UK’s central and evolved administrations. Finally, EU membership has important implications concerning the UK’s implementation of international obligations in areas such as climate change law or air pollution. In these areas, EU law is often more ambitious than the underlying international obligations. Brexit will therefore confront the UK and devolved administrations with fundamental choices regarding how to continue to comply with international obligations, and maintain and enhance their current level of commitment and ambition over time

    Formulation of Shannon entropy model averaging for groundwater level prediction using artificial intelligence models

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    A two-level modeling strategy is formulated to predict groundwater levels (GWL) within a portion of Lake Urmia’s aquifer in NW Iran during 14 years (2001–2015), which both aquifer and lake suffer significant water decline. At Level 1, three artificial intelligence (AI) models were trained and tested, which comprise artificial neural network (ANN), Sugeno fuzzy logic (SFL), and neuro-fuzzy (NF). At Level 2, a novel formulation was employed, referred to as the Shannon entropy model averaging (EMA). This formulation combines the results at Level 1 by calculating the weights of Level 1 models based on an innovative approach, which incorporates performance, stability, and parsimony criteria. The results indicate that the models at Level 1 are fit-for-purpose and can capture the water table decline in GWL, but EMA improves RMSE by 5% in the testing phase. Although EMA does not significantly increase the performance of the models, the results of the homoscedastic test in models’ residuals indicate that EMA increases the reliability of prediction owing to the homoscedastic residuals with the highest p value compared to Level 1 models. The p values as per Breusch–Pagan and White tests are 0.88 and 1, respectively, which indicates further information does not remain in the EMA residual. The EMA formulation can be applied to other water resource management problems

    Simulating Future Groundwater Recharge in Coastal and Inland Catchments

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    Groundwater is a primary source of drinking water in the Mediterranean, however, climate variability in conjunction with mismanagement renders it vulnerable to depletion. Spatiotemporal studies of groundwater recharge are the basis to develop strategies against this phenomenon. In this study, groundwater recharge was spatiotemporally quantified using the Soil and Water Assessment Tool (SWAT) in one coastal and one inland hydrological basin in Greece. A double calibration/validation (CV) procedure using streamflow data and MODIS ET was conducted for the inland basin of Mouriki, whereas only ET values were used in the coastal basin of Anthemountas. Calibration and simulation recharge were accurate in both sites according to statistical indicators and previous studies. In Mouriki basin, mean recharge and runoff were estimated as 16% and 9%, respectively. In Anthemountas basin recharge to the shallow aquifer and surface runoff were estimated as 12% and 16%, respectively. According to the predicted RCP 4.5 and 8.5 scenarios, significant variations in groundwater recharge are predicted in the coastal zone for the period 2020–2040 with average annual recharges decreasing by 30% (RCP 4.5) and 25% (RCP 8.5). Variations in groundwater recharge in the inland catchment of Mouriki were insignificant for the simulated period. Anthemountas basin was characterized by higher runoff rates. Groundwater management in coastal aquifers should include detailed monitoring of hydrological parameters, reinforced groundwater recharge during winter and reduced groundwater abstraction during summer depending on the spatiotemporal distribution of groundwater recharge

    Hydrogeological and hydrochemical regime evaluation in flamouria basin in edessa (Northern Greece)

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    Groundwater quality deterioration and overexploitation constitute two critical environmental issues worldwide. In this study, with the aim to achieve a groundwater sustainability purpose, a preliminary hydrogeochemical survey is conducted in the Flamouria basin, Pella prefecture, Northern Greece using available and collected data. For this purpose, chemical analyses of groundwater, springs, and surface water were collected and analyzed with three electrical resistivity tomographies (ERTs). A Groundwater Quality Index (GQI), along with a nitrate susceptibility assessment is applied within the porous aquifer. The water quality analysis along with GQI application showed excellent water quality for potable and irrigation use however highlighted future issue for irrigation utilization as the high alkalinity and total dissolved solid (TDS)could generate excessive soil salinization. Moreover, the application of a methodology for the identification of “Nitrate Vulnerable Zone” called the Protection from Natural and Anthropogenic sources (PNA) highlighted the natural susceptibility to nitrate pollution of the porous aquifer, especially in the central part of the area where most agricultural activity is localized. The work further confirmed how the proposed elaboration could represent an easy and widely applicable hydrological assessment where there is also limited data available

    Predictive modeling of selected trace elements in groundwater using hybrid algorithms of iterative classifier optimizer

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    none10siTrace 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.restrictedKhosravi K.; Barzegar R.; Golkarian A.; Busico G.; Cuoco E.; Mastrocicco M.; Colombani N.; Tedesco D.; Ntona M.M.; Kazakis N.Khosravi, K.; Barzegar, R.; Golkarian, A.; Busico, G.; Cuoco, E.; Mastrocicco, M.; Colombani, N.; Tedesco, D.; Ntona, M. M.; Kazakis, N

    The origin of Uranium in groundwater of the eastern Halkidiki region, northern Greece

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    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
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