Articles de revues : « Water management, MODELLING, COASTAL AQUIFER »

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Olabode, Oluwaseun Franklin, et Jean-Christophe Comte. « Modelling of groundwater recharge in the megacity of Lagos, Nigeria : preliminary results using WetSpass-M ». Advances in Geosciences 59 (20 décembre 2022) : 53–57. http://dx.doi.org/10.5194/adgeo-59-53-2022.

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Abstract. Lagos, Nigeria is one of the World's fastest-growing cities. The increasing water demand has led to depletion and deterioration of the groundwater resources contained in its highly productive coastal aquifers. Groundwater recharge processes and drivers, which dictate groundwater replenishment, and their changes associated with rapid urbanization, are yet to be quantified and understood. We used the spatially distributed WetSpass-M model to estimate the spatiotemporal patterns and rates of recharge between 2000 and 2020 in the 5440 km2 coastal aquifer system underlying the megacity of Lagos. The influence of expanding urban areas, from 807 km2 in 2000 to 1183 km2 in 2020, coincide with reduction in the simulated recharge by 50 % in 20 years. The study also revealed diffuse and focused recharge processes associated with, respectively, the urban centres and areas closer to water bodies signalling strong groundwater-surface water interactions. The preliminary findings from this modelling work provide directions for exploring sustainable water management options including Managed Aquifer Recharge (MAR) in Lagos and other fast-growing coastal megacities in the world.

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Timaniya, Aman, et Nayankumar Soni. « “Modeling of Saline Water Intrusion using MODFLOW in Una Coastal Aquifer of Gujarat, India.” ». International Journal for Research in Applied Science and Engineering Technology 10, n^o 5 (31 mai 2022) : 634–40. http://dx.doi.org/10.22214/ijraset.2022.42309.

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Abstract: Groundwater is the most valuable and extensively dispersed resource on the planet, and unlike any other mineral resource, it is replenished annually by meteoric precipitation. The present study would include simulation and modelling of the problem of seawater intrusion in the Una coastal area of Gujarat. The interrelationships of two miscible fluids in porous media have been widely explored both theoretically and experimentally. Because of the extreme salinity, many agricultural wells are no longer used. This high salinity is a sign of a process known as saltwater intrusion, which occurs mostly in coastal aquifers due to excessive pumping. Modelling software has also been utilized to analyze the behavior of groundwater flow models. Numerical models may simulate diverse groundwater scenarios and link them to groundwater management. To simulate seawater intrusion, MODFLOW-2005, a grid-based variable density-dependent flow model, is used. Water balance research reveals that rainwater recharge is the aquifer's primary input. To compute the water level in the area and estimate the position of the seawater intrusion barrier, the saltwater intrusion phenomena were simulated using the MODFLOW software combined with the SWI2 package. The model was used to visualize the salinity levels of the coastal aquifer's groundwater and their fluctuation over time and space from May 2004 to October 2014. The model was developed for a 10-year stress period with 100-time steps, which included a 5-year steady state and 5 years transient state stress period using the previous 10 years of pre-monsoon and postmonsoon data. This research would assist to describe Pumping's impact on groundwater levels and seawater intrusion was studied. Keywords: MODFLOW, Saltwater Intrusion, Modelling, Numerical Model, Coastal aquifer

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Dibaj, Mahdieh, Akbar A. Javadi, Mohammad Akrami, Kai-Yuan Ke, Raziyeh Farmani, Yih-Chi Tan et Albert S. Chen. « Modelling seawater intrusion in the Pingtung coastal aquifer in Taiwan, under the influence of sea-level rise and changing abstraction regime ». Hydrogeology Journal 28, n^o 6 (23 mai 2020) : 2085–103. http://dx.doi.org/10.1007/s10040-020-02172-4.

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Abstract A three-dimensional variable-density finite element model was developed to study the combined effects of overabstraction and seawater intrusion in the Pingtung Plain coastal aquifer system in Taiwan. The model was generated in different layers to represent the three aquifers and two aquitards. Twenty-five multilayer pumping wells were assigned to abstract the groundwater, in addition to 95 observation wells to monitor the groundwater level. The analysis was carried out for a period of 8 years (2008–2015 inclusive). Hydraulic head, soil permeability, and precipitation were assigned as input data together with the pumping records in different layers of the aquifer. The developed numerical model was calibrated against the observed head archives and the calibrated model was used to predict the inland encroachment of seawater in different layers of the aquifer. The effects of pumping rate, sea-level rise, and relocation of wells on seawater intrusion were examined. The results show that all layers of the aquifer system are affected by seawater intrusion; however, the lengths of inland encroachment in the top and bottom aquifers are greater compared with the middle layer. This is the first large-scale finite-element model of the Pingtung Plain, which can be used by decision-makers for sustainable management of groundwater resources and cognizance of seawater intrusion in coastal aquifers.

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Grundmann, J., N. Schütze et V. Heck. « Optimal integrated management of groundwater resources and irrigated agriculture in arid coastal regions ». Proceedings of the International Association of Hydrological Sciences 364 (16 septembre 2014) : 216–21. http://dx.doi.org/10.5194/piahs-364-216-2014.

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Abstract. Groundwater systems in arid coastal regions are particularly at risk due to limited potential for groundwater replenishment and increasing water demand, caused by a continuously growing population. For ensuring a sustainable management of those regions, we developed a new simulation-based integrated water management system. The management system unites process modelling with artificial intelligence tools and evolutionary optimisation techniques for managing both water quality and water quantity of a strongly coupled groundwater–agriculture system. Due to the large number of decision variables, a decomposition approach is applied to separate the original large optimisation problem into smaller, independent optimisation problems which finally allow for faster and more reliable solutions. It consists of an analytical inner optimisation loop to achieve a most profitable agricultural production for a given amount of water and an outer simulation-based optimisation loop to find the optimal groundwater abstraction pattern. Thereby, the behaviour of farms is described by crop-water-production functions and the aquifer response, including the seawater interface, is simulated by an artificial neural network. The methodology is applied exemplarily for the south Batinah re-gion/Oman, which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture. Due to contradicting objectives like profit-oriented agriculture vs aquifer sustainability, a multi-objective optimisation is performed which can provide sustainable solutions for water and agricultural management over long-term periods at farm and regional scales in respect of water resources, environment, and socio-economic development.

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Grundmann, Jens, Ayisha Al-Khatri et Niels Schütze. « Managing saltwater intrusion in coastal arid regions and its societal implications for agriculture ». Proceedings of the International Association of Hydrological Sciences 373 (12 mai 2016) : 31–35. http://dx.doi.org/10.5194/piahs-373-31-2016.

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Abstract. Coastal aquifers in arid and semiarid regions are particularly at risk due to intrusion of salty marine water. Since groundwater is predominantly used in irrigated agriculture, its excessive pumping – above the natural rate of replenishment – strengthen the intrusion process. Using this increasingly saline water for irrigation, leads to a destruction of valuable agricultural resources and the economic basis of farmers and their communities. The limitation of resources (water and soil) in these regions requires a societal adaptation and change in behaviour as well as the development of appropriate management strategies for a transition towards stable and sustainable future hydrosystem states. Besides a description of the system dynamics and the spatial consequences of adaptation on the resources availability, the contribution combines results of an empirical survey with stakeholders and physically based modelling of the groundwater-agriculture hydrosystem interactions. This includes an analysis of stakeholders' (farmers and decision makers) behaviour and opinions regarding several management interventions aiming on water demand and water resources management as well as the thinking of decision makers how farmers will behave. In this context, the technical counter measures to manage the saltwater intrusion by simulating different groundwater pumping strategies and scenarios are evaluated from the economic and social point of view and if the spatial variability of the aquifer's hydrogeology is taken into consideration. The study is exemplarily investigated for the south Batinah region in the Sultanate of Oman, which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture.

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Frollini, Eleonora, Daniele Parrone, Stefano Ghergo, Rita Masciale, Giuseppe Passarella, Maddalena Pennisi, Matteo Salvadori et Elisabetta Preziosi. « An Integrated Approach for Investigating the Salinity Evolution in a Mediterranean Coastal Karst Aquifer ». Water 14, n^o 11 (27 mai 2022) : 1725. http://dx.doi.org/10.3390/w14111725.

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Coastal areas are characterized by considerable demographic pressure that generally leads to groundwater overexploitation. In the Mediterranean region, this situation is exacerbated by a recharge reduction enhanced by climate change. The consequence is water table drawdown that alters the freshwater/seawater interface facilitating seawater intrusion. However, the groundwater salinity may also be affected by other natural/anthropogenic sources. In this paper, water quality data gathered at 47 private and public wells in a coastal karst aquifer in Apulia (southern Italy), were interpreted by applying disparate methods to reveal the different sources of groundwater salinity. Chemical characterization, multivariate statistical analysis, and mixing calculations supplied the groundwater salinization degree. Characteristic ion ratios, strontium isotope (87Sr/86Sr), and pure mixing modelling identified the current seawater intrusion as a main salinity source, also highlighting the contribution of water–rock interaction to groundwater composition and excluding influence from Cretaceous paleo-seawater. Only the combined approach of all the methodologies allowed a clear identification of the main sources of salinization, excluding other less probable ones (e.g., paleo-seawater). The proposed approach enables effective investigation of processes governing salinity changes in coastal aquifers, to support more informed management.

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Pavelic, Paul, Kumar A. Narayan et Peter J. Dillon. « Groundwater flow modelling to assist dryland salinity management of a coastal plain of southern Australia ». Soil Research 35, n^o 4 (1997) : 669. http://dx.doi.org/10.1071/s96101.

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Groundwater flow modelling has been undertaken for an area of 10 500 ha within the regional unconfined aquifer system of a coastal plain of southern Australia, in the vicinity of the town of Cooke Plains, to predict the impact of various land management options (including recharge reduction and discharge enhancement) on the extent of land salinisation caused by shallow saline watertables. The model was calibrated against field data collected over 6 years. Sensitivity analysis was performed to assess the influence of mesh size, boundary conditions, and aquifer parameters, and particularly rates of recharge and evaporative discharge, on groundwater levels. These were varied until the model was shown to be capable of simulating seasonal trends and regional and local flow patterns. The model was then used to predict the impact of the management options on groundwater levels. The results showed that continuing current annual crop–pasture rotations will result in watertable rises of approximately 0·2 m in 20 years (significant in this setting), with a further 50 ha of land salinised. A reduction in the rates of groundwater recharge through the establishment of high water-use perennial pastures (e.g. lucerne) showed the most promise for controlling groundwater levels. For example, a reduction in recharge by 90% would result in watertable declines of 0·6–1·0 m within 5–10 years, with the return to productivity of 180 ha of saline land. Small-scale (say <100 ha) efforts to reduce recharge were found to have no significant impact on groundwater levels. Enhanced groundwater discharge such as pumping from a windmill was found to be non-viable due to the relatively high aquifer transmissivity and specific yield. The modelling approach has enabled a relatively small area within a regional aquifer system to be modelled for a finite time (20 years) and has shown that extension of the boundaries of the model would not have altered the predicted outcomes. Furthermore, the analysis of sensitivity to cell size in an undulating landscape where net recharge areas can become net discharge areas with only small increases in groundwater level is novel, and has helped to build confidence in the model. Modelling has demonstrated that dryland salinisation can be controlled by reducing groundwater recharge over substantial tracts of land, and is not dependent on recharge reduction over an extensive area upgradient, at least over the next 20 years.

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Dieu, Linh Pham, Diep Cong-Thi, Tom Segers, Huu Hieu Ho, Frédéric Nguyen et Thomas Hermans. « Groundwater Salinization and Freshening Processes in the Luy River Coastal Aquifer, Vietnam ». Water 14, n^o 15 (30 juillet 2022) : 2358. http://dx.doi.org/10.3390/w14152358.

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The Vietnamese Binh Thuan province located along the Southern Central part of the coast is one of the driest in the country. The population is relying largely on groundwater for irrigation, and the groundwater resources are threatened by climate change and saltwater intrusion in river estuaries. Recent studies, however, reveal that the extension of saltwater intrusions was larger than expected, raising some doubts on the actual origin of the intrusions. In this study, we use the geochemical characterization of groundwater samples collected in both the dry and rainy seasons in the Luy river coastal area to identify hydrochemical processes responsible for the salinization and variations taking place in the shallow aquifers. The distribution of chemical components of groundwater and the indicators presenting the freshening and salinization processes, such as cation exchange code and chloride conservative element, the ionic delta, the HFE-diagram, and geochemical modelling, were studied. The results show that 65% of the samples exceed the WHO limit for drinking water and 100% of them have a degree of restriction on use from slight–moderate to severe in potential irrigation problems according to FAO. In contrast to previous expectations, freshening is the dominant process in the aquifers, and it is more advanced in the rainy season. Due to a lack of recharge and aquifer exploitation, salinization is more severe in the deeper aquifer and during the dry season. Saltwater intrusion is not limited to the zone close to the river but extends further inland and at depth, and salinity can vary quickly over short distances. Based on these new insights, we develop a new conceptual model for the evolution of salinization in the Luy river catchment involving a natural freshening process of connate water combined with anthropic influence. The conceptual model will form the basis for the development of a groundwater model of the study area and eventually lead to sustainable management scenarios for this coastal region, preventing further deterioration of the groundwater resources.

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Tziritis, Evangelos, Ekaterini Sachsamanoglou et Vassilis Aschonitis. « Assessing Groundwater Evolution with a Combined Approach of Hydrogeochemical Modelling and Data Analysis : Application to the Rhodope Coastal Aquifer (NE Greece) ». Water 15, n^o 2 (5 janvier 2023) : 230. http://dx.doi.org/10.3390/w15020230.

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Assessing the hydrogeochemical evolution of groundwater is a challenging task, which is further exacerbated when considering the multiple geogenic and anthropogenic impacts that affect its quality and the hydraulic interactions between different aquifer bodies. This study combined hydrogeochemical modelling and data analysis to assess this complex hydrogeological regime. Before modelling, the groundwater samples were clustered using a multivariate statistical method (hierarchical cluster analysis (HCA)). Then, the Geochemist Workbench (GWB) software was applied to model the hydrogeochemical groundwater evolution, including the dominant ion exchange process, and to explain the changes in groundwater chemistry towards its flow. The input data consisted of five key parameters from seventy-seven sampling points collected in two periods (accounting for the start and the end of the irrigation period). A data analytical approach based on the optimal mixing ratios between the interacting groundwater systems and recharge inputs was also performed as part of the methodological approach. It revealed a progressively temporal-dependent behaviour of the aquifer system during the irrigation period, resulting in seasonal changes in the hydrodynamic conditions and depletion of the upper aquifer layers. Specifically, the aquifer system was confirmed to undergo cation exchange as the dominant geochemical process that increases calcium concentrations. The complex hydrogeological regime was further evaluated by assessing the mixing ratios of the different aquifer layers. Hence, the aquifer system (bulk samples) was mixed with the irrigation water by 71% and 97% and with the lateral recharge by 76% and 29% for the beginning and at the end of the irrigation period, respectively. Overall, the joint assessments were confirmed by the hydrogeochemical status of the end-members and the modelling approach and explained the sequential changes in groundwater chemistry due to the dominant ion-exchange process and the mixing of different water bodies. The proposed methodological approach proved that it could be used as an exploratory and preliminary method for capturing the temporal dynamics in complex groundwater systems and supporting groundwater resource management.

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Roy, Dilip Kumar, et Bithin Datta. « Modelling and management of saltwater intrusion in a coastal aquifer system : A regional-scale study ». Groundwater for Sustainable Development 11 (octobre 2020) : 100479. http://dx.doi.org/10.1016/j.gsd.2020.100479.

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Grundmann, Jens, Niels Schütze et Franz Lennartz. « Sustainable management of a coupled groundwater–agriculture hydrosystem using multi-criteria simulation based optimisation ». Water Science and Technology 67, n^o 3 (1 février 2013) : 689–98. http://dx.doi.org/10.2166/wst.2012.602.

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In this paper we present a new simulation-based integrated water management tool for sustainable water resources management in arid coastal environments. This tool delivers optimised groundwater withdrawal scenarios considering saltwater intrusion as a result of agricultural and municipal water abstraction. It also yields a substantially improved water use efficiency of irrigated agriculture. To allow for a robust and fast operation we unified process modelling with artificial intelligence tools and evolutionary optimisation techniques. The aquifer behaviour is represented using an artificial neural network (ANN) which emulates a numerical density-dependent groundwater flow model. The impact of agriculture is represented by stochastic crop water production functions (SCWPF). Simulation-based optimisation techniques together with the SCWPF and ANN deliver optimal groundwater abstraction and cropping patterns. To address contradicting objectives, e.g. profit-oriented agriculture vs. sustainable abstraction scenarios, we performed multi-objective optimisations using a multi-criteria optimisation algorithm.

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Cech, Irina, Mengistu Lemma, Charles W. Kreitler et Howard M. Prichard. « Radium and radon in water supplies from the Texas Gulf Coastal aquifer ». Water Research 22, n^o 1 (janvier 1988) : 109–21. http://dx.doi.org/10.1016/0043-1354(88)90137-6.

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Abdelfattah, Mohamed, Heba Abdel-Aziz Abu-Bakr, Ahmed Gaber, Mohamed H. Geriesh, Ashraf Y. Elnaggar, Nihal El Nahhas et Taher Mohammed Hassan. « Proposing the Optimum Withdrawing Scenarios to Provide the Western Coastal Area of Port Said, Egypt, with Sufficient Groundwater with Less Salinity ». Water 13, n^o 23 (26 novembre 2021) : 3359. http://dx.doi.org/10.3390/w13233359.

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Recently, groundwater resources in Egypt have become one of the important sources to meet human needs and activities, especially in coastal areas such as the western area of Port Said, where seawater desalination cannot be used due to the problem of oil spill and the reliance upon groundwater resources. Thus, the purpose of the study is the sustainable management of the groundwater resources in the coastal aquifer entailing groundwater abstraction. In this regard, the Visual MODFLOW and SEAWAT codes were used to simulate groundwater flow and seawater intrusion in the study area for 50 years (from 2018 to 2068) to predict the drawdown, as well as the salinity distribution due to the pumping of the wells on the groundwater coastal aquifer based on field investigation data and numerical modelling. Different well scenarios were used, such as the change in well abstraction rate, the different numbers of abstraction wells, the spacing between the abstraction wells and the change in screen depth in abstraction. The recommended scenarios were selected after comparing the predicted drawdown and salinity results for each scenario to minimize the seawater intrusion and preserve these resources from degradation.

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Kooi, H., et J. Groen. « Geological processes and the management of groundwater resources in coastal areas ». Netherlands Journal of Geosciences - Geologie en Mijnbouw 82, n^o 1 (avril 2003) : 31–40. http://dx.doi.org/10.1017/s0016774600022770.

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AbstractIn this contribution, a case is made for the significance of sedimentation and sea-level change for groundwater management of coastal areas. In groundwater practice these geological processes are rarely considered. The role of sediment loading in causing anomalous fluid pressures and flow fields in relatively shallow aquifer systems is discussed and illustrated via both case studies and generic modelling studies. The role of sea-level changes in controlling current salinity distributions is discussed likewise. Central in the discussion is the concept of memory of groundwater systems, which provides the basic reason why processes that were operative in the geological past are still of relevance today. It is argued and shown that awareness and knowledge of the influence of sediment loading and sea level change on current hydrological conditions can lead to improved characterization of the distribution of hydraulic parameters and of the distribution of water quality in coastal areas. This improved characterization, in turn, serves to enhance the validity of impact assessment studies for the long-term development and management of those areas.

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Refsgaard, A., T. Jacobsen, B. Jacobsen et J. E. Ørum. « Integrated modelling of nitrate loads to coastal waters and land rent applied to catchment-scale water management ». Water Science and Technology 56, n^o 1 (1 juillet 2007) : 39–47. http://dx.doi.org/10.2166/wst.2007.434.

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The EU Water Framework Directive (WFD) requires an integrated approach to river basin management in order to meet environmental and ecological objectives. This paper presents concepts and full-scale application of an integrated modelling framework. The Ringkoebing Fjord basin is characterized by intensive agricultural production and leakage of nitrate constitute a major pollution problem with respect groundwater aquifers (drinking water), fresh surface water systems (water quality of lakes) and coastal receiving waters (eutrophication). The case study presented illustrates an advanced modelling approach applied in river basin management. Point sources (e.g. sewage treatment plant discharges) and distributed diffuse sources (nitrate leakage) are included to provide a modelling tool capable of simulating pollution transport from source to recipient to analyse the effects of specific, localized basin water management plans. The paper also includes a land rent modelling approach which can be used to choose the most cost-effective measures and the location of these measures. As a forerunner to the use of basin-scale models in WFD basin water management plans this project demonstrates the potential and limitations of comprehensive, integrated modelling tools.

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De Filippis, Giovanna, Stefano Margiotta, Claudia Branca et Sergio Luigi Negri. « A Modelling Approach for Assessing the Hydrogeological Equilibrium of the Karst, Coastal Aquifer of the Salento Peninsula (Southeastern Italy) : Evaluating the Effects of a MAR Facility for Wastewater Reuse ». Geofluids 2019 (14 mai 2019) : 1–19. http://dx.doi.org/10.1155/2019/5714535.

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The Salento Peninsula is characterized by poor surface water resources, due to the karstic nature of its territory. On the other hand, important groundwater resources are located in the deep, karst, coastal aquifer, which is of strategic importance for the economic and social development of the area. The increasing water demand, however, if not properly managed may pose serious problems to the hydrogeological equilibrium of this aquifer, which is highly susceptible to natural and anthropogenic changes and to saltwater intrusion. Taking steps from the previous works, the present paper focuses on the characterization of the deep aquifer of the Adriatic portion of the Salento Peninsula from a quantitative point of view by means of modelling tools for the simulation of groundwater dynamics. Conclusions about the extent of the saltwater intrusion phenomenon are consequently inferred. As a result of the implementation of a density-dependent flow model, the lateral extent of such phenomenon and the vertical depth of the transition zone between freshwater and saltwater were inferred, highlighting also the role of major faults which characterize the hydraulic behaviour of the karst system under exam. The model was also applied to design a Managed Aquifer Recharge facility for management and protection of the hydrogeological equilibrium of the deep aquifer. Its positive effects on the advancement of the saline front were highlighted. Model results also allowed identifying areas where the lack of data prevents a proper comprehension of the hydrogeological processes investigated, thus representing a supporting tool for planning further monitoring campaigns.

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Aladejana, Jamiu A., Robert M. Kalin, Philippe Sentenac et Ibrahim Hassan. « Assessing the Impact of Climate Change on Groundwater Quality of the Shallow Coastal Aquifer of Eastern Dahomey Basin, Southwestern Nigeria ». Water 12, n^o 1 (14 janvier 2020) : 224. http://dx.doi.org/10.3390/w12010224.

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Despite the increasing interest in climate change and water security, research linking climate change and groundwater quality is still at an early stage. This study explores the seasonal effect of the change in biogeochemical process for the redox-sensitive ions and metals Fe2+, Mn2+, SO42−, and NO3− to assess the groundwater quality of the shallow coastal aquifer of Eastern Dahomey Basin in southwestern Nigeria. Field physicochemical measurement of EC, pH TDS, Eh, salinity, temperature, and the static water level (SWL) was carried out on 250 shallow wells; 230 water samples were collected for analysis between June 2017 and April 2018. A spatial distribution map of these ions and metals showed an increasing concentration in the dry season water samples compared to those of the wet season. This higher concentration could be attributed to change in the intensity of hydrochemical processes such as evaporation, redox, and mineral precipitation. Results of linear regression modelling established significant relationships between SWL, SO42−, NO3−, Fe, and Eh for both wet and dry seasons with the p-value falling between 75% and 95%, which can also be seen in the plots of Eh/ORP against Fe2+, Mn2+, SO42−, and NO3−. These results revealed the influence of the redox process for both seasons, while also having a higher impact in the dry season while variation of concentration revealed decrease with increase in depth, which could be attributed to a decrease in well hydraulic properties and aeration. An Eh-pH geochemical diagram revealed NO3− as the controlling biogeochemical process over Fe in most of the sample wells. Concentrations of NO3−, Fe, and Mn are above the World Health Organization’s (WHO) standard for drinking water in most water samples. This study has established the link between climate change and groundwater quality in shallow coastal aquifers and suggested the need for strategic groundwater management policy and planning to ameliorate groundwater quality deterioration.

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Weng, Ph, F. Giraud, P. Fleury et C. Chevallier. « Characterising and modelling groundwater discharge in anagricultural wetland on the French Atlantic coast ». Hydrology and Earth System Sciences 7, n^o 1 (28 février 2003) : 33–42. http://dx.doi.org/10.5194/hess-7-33-2003.

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Abstract. Interaction between a wetland and its surrounding aquifer was studied in the Rochefort agricultural marsh (150 km2). Groundwater discharge in the marsh was measured with a network of nested piezometers. Hydrological modelling of the wetland showed that a water volume of 770,000 m3 yr–1 is discharging into the marsh, but that this water flux essentially takes place along the lateral borders of the wetland. However, this natural discharge volume represents only 20% of the artificial freshwater injected each year into the wetland to maintain the water level close to the soil surface. Understanding and quantifying the groundwater component in wetland hydrology is crucial for wetland management and conservation. Keywords: wetland, hydrology, groundwater, modelling, marsh

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Mondal, Raka, Graham Benham, Sourav Mondal, Paul Christodoulides, Natasa Neokleous et Katerina Kaouri. « Modelling and optimisation of water management in sloping coastal aquifers with seepage, extraction and recharge ». Journal of Hydrology 571 (avril 2019) : 471–84. http://dx.doi.org/10.1016/j.jhydrol.2019.01.060.

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Sbai, Mohammed Adil, Abdelkader Larabi, Marwan Fahs et Joanna Doummar. « A New Normalized Groundwater Age-Based Index for Quantitative Evaluation of the Vulnerability to Seawater Intrusion in Coastal Aquifers : Implications for Management and Risk Assessments ». Water 13, n^o 18 (11 septembre 2021) : 2496. http://dx.doi.org/10.3390/w13182496.

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The vulnerability of coastal aquifers to seawater intrusion has been largely relying on data-driven indexing approaches despite their shortcomings to depict the complex processes of groundwater flow and mass transport under variable velocity conditions. This paper introduces a modelling-based alternative technique relying on a normalized saltwater age vulnerability index post-processed from results of a variable density flow simulation. This distributed index is obtained from the steady-state distribution of the salinity and a restriction of the mean groundwater age to a mean saltwater age distribution. This approach provides a novel way to shift from the concentration space into a vulnerability assessment space to evaluate the threats to coastal aquifers. The method requires only a sequential numerical solution of two steady state sets of equations. Several variants of the hypothetical Henry problem and a case study in Lebanon are selected for demonstration. Results highlight this approach ability to rank, compare, and validate different scenarios for coastal water resources management. A novel concept of zero-vulnerability line/surface delineating the coastal area threatened by seawater intrusion has shown to be relevant for optimal management of coastal aquifers and risk assessments. Hence, this work provides a new tool to sustainably manage and protect coastal groundwater resources.

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Hoang, Nguyen Van, Trinh Hoai Thu, Renat Shakirov, Tran Thi Thuy Huong et Nadezhda Syrbu. « Estimation of Groundwater Recharge from Rainfall for Arid Coastal Plain of Ninh Thuan Province, Vietnams ». Russian Journal of Earth Sciences 22, n^o 1 (17 février 2022) : 1–16. http://dx.doi.org/10.2205/2022es000775.

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Estimation of groundwater recharge from rainfall is a key factor for determining groundwater resources in water development and management for supporting sustainable socio-economic development, especially for arid areas. The paper presents finite element modeling in the simulation of moisture transfer in unsaturated soils through the relationship between soil moisture, soil suction, unsaturated permeability and soil-moisture dispersivity. Those parameters required for soil moisture transfer are derived from the soil-water characteristic curve functions. Element sizes and time steps used in the modelling have been selected based on a detailed analysis of numerical simulation errors. The methodology had been applied to arid coastal plain area of Ninh Thuan province, Vietnam. Five subsurface soil types in the study area have been collected and analyzed, for saturated permeability, porosity, saturated soil water content, field moisture content, etc. Hourly rainfall data of the years 2014–2018 have been analyzed and grouped into different-duration rainfall events (1-hour, 2-hour, 3-hour and so on). The different rainfall durations and depths of rainfall events and temporal infiltration determined by the moisture transfer modelling have allowed determining the groundwater recharge from the rainfall data. The results show that during the rainy months from May to December 2014–2018, the groundwater recharge from the rainfall is very varying through the modeled soil profiles, from 0.280 m (silty clay) to 0.470 m (sandy silt), which is equivalent to 33.3%—55.2% of the rainfall depth during May—December. Lower infiltration in silty clay is due to low permeability and in the sand is due to low suction, and higher infiltration in silt and sandy silt is thanks to their higher moisture dispersivity. On average, in terms of annual rainfall and soil properties, the average infiltration during May—December is 0.380 m which is equivalent to 44.9% of the rainfall depth, which is about 289 106 m3 of rainwater infiltrated into the Quaternary aquifer over 760 km2 of the coastal plain of Ninh Thuan province. The results would be very useful for effective water resources development and management in a given specific hydrogeological condition for such a severe drought area where water is extremely essential.

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McDonough, Liza K., Denis M. O’Carroll, Karina Meredith, Martin S. Andersen, Clément Brügger, Hanxue Huang, Helen Rutlidge et al. « Changes in groundwater dissolved organic matter character in a coastal sand aquifer due to rainfall recharge ». Water Research 169 (février 2020) : 115201. http://dx.doi.org/10.1016/j.watres.2019.115201.

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De Filippis, Giovanna, Christos Pouliaris, Daniel Kahuda, Teodora Vasile, Valentina Manea, Florian Zaun, Björn Panteleit et al. « Spatial Data Management and Numerical Modelling : Demonstrating the Application of the QGIS-Integrated FREEWAT Platform at 13 Case Studies for Tackling Groundwater Resource Management ». Water 12, n^o 1 (20 décembre 2019) : 41. http://dx.doi.org/10.3390/w12010041.

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Because of the spatial nature of groundwater-related data and their time component, effective groundwater management requires the application of methods pertaining to the Information and Communication Technologies sector, such as spatial data management and distributed numerical modelling. The objective of this paper is to demonstrate the effectiveness of the QGIS-integrated FREEWAT platform and an approach combining spatial data management and numerical models to target groundwater management issues. FREEWAT is a free and open source platform integrated in a Geographic Information System environment and embedding tools for pre- and post-processing of spatial data and integrating numerical codes for the simulation of the hydrological cycle, with a main focus on groundwater. To this aim, this paper briefly presents the FREEWAT platform, introduces the FREEWAT approach, and showcases 13 case studies in European and non-European countries where the FREEWAT platform was applied. Application of the FREEWAT platform to real-world case studies is presented for targeting management of coastal aquifers, ground- and surface-water interaction, climate change impacts, management of transboundary aquifers, rural water management and protection of groundwater-dependent ecosystems. In this sense, compared to other existing software suites, FREEWAT allows data analysis and visualization to accomplish each step of the modelling workflow, i.e., from data analytics, to conceptual model definition, to numerical modelling and reporting of results. The presented experiences demonstrate that improved access to data and the portability of models and models’ results can help to promote water sustainability from the local- to the basin-scale. Furthermore, FREEWAT may represent a valuable tool to target the objective of increasing the capabilities of public authorities and private companies to manage groundwater resources by means of up-to-date, robust, well-documented and reliable software, without entailing the need of costly licensing, nowadays seldom affordable by public water authorities. Based on the strengths highlighted, the FREEWAT platform is a powerful tool for groundwater resources management, and for data collection, sharing, implementation and comparison of scenarios, for supporting planning and decision-making.

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Kaplan, Nicole, et Mordeckai Magaritz. « A nitrogen-isotope study of the sources of nitrate contamination in groundwater of the pleistocene coastal plain aquifer, Israel ». Water Research 20, n^o 2 (février 1986) : 131–35. http://dx.doi.org/10.1016/0043-1354(86)90002-3.

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Mabrouk, M. B., A. Jonoski, D. Solomatine et S. Uhlenbrook. « A review of seawater intrusion in the Nile Delta groundwater system – the basis for assessing impacts due to climate changes and water resources development ». Hydrology and Earth System Sciences Discussions 10, n^o 8 (19 août 2013) : 10873–911. http://dx.doi.org/10.5194/hessd-10-10873-2013.

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Abstract. Serious environmental problems are emerging in the River Nile basin and its groundwater resources. Recent years have brought scientific evidence of climate change and development-induced environmental impacts globally as well as over Egypt. Some impacts are subtle, like decline of the Nile River water levels, others are dramatic like the salinization of all coastal land in the Nile Delta – the agricultural engine of Egypt. These consequences have become a striking reality causing a set of interconnected groundwater management problems. Massive population increase that overwhelmed the Nile Delta region has amplified the problem. Many researchers have studied these problems from different perspectives using different methodologies, following different objectives and, consequently, arrived at different findings. However, they all confirmed that significant groundwater salinization has affected the Nile Delta and this is likely to become worse rapidly in the future. This article presents, categorizes and critically analyses and synthesizes the most relevant research regarding climate change and development challenges in relation to groundwater resources in the Nile Delta. It is shown that there is a gap in studies that focus on sustainable groundwater resources development and environmentally sound protection as an integrated regional process in Nile Delta. Moreover, there is also a knowledge gap related to the deterioration of groundwater quality. The article recommends further research that covers the groundwater resources and salinization in the whole Nile Delta based on integrated three-dimensional groundwater modelling of the Nile delta aquifer.

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Roy, Dilip Kumar, et Bithin Datta. « An Ensemble Meta-Modelling Approach Using the Dempster-Shafer Theory of Evidence for Developing Saltwater Intrusion Management Strategies in Coastal Aquifers ». Water Resources Management 33, n^o 2 (17 novembre 2018) : 775–95. http://dx.doi.org/10.1007/s11269-018-2142-y.

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Stein, Shaked, Orit Sivan, Yoseph Yechieli et Roni Kasher. « Redox condition of saline groundwater from coastal aquifers influences reverse osmosis desalination process ». Water Research 188 (janvier 2021) : 116508. http://dx.doi.org/10.1016/j.watres.2020.116508.

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Bear, Jacob. « Management of a Coastal Aquifer ». Ground Water 42, n^o 3 (mai 2004) : 317. http://dx.doi.org/10.1111/j.1745-6584.2004.tb02677.x.

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Criminisi, A., et T. Tucciarelli. « Water Level Measurement Locations for Coastal Aquifer Management ». Journal of Water Resources Planning and Management 129, n^o 1 (janvier 2003) : 49–58. http://dx.doi.org/10.1061/(asce)0733-9496(2003)129:1(49).

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B.N., Priyanka, et M. S. Mohan Kumar. « Three-Dimensional Modelling of Heterogeneous Coastal Aquifer : Upscaling from Local Scale ». Water 11, n^o 3 (27 février 2019) : 421. http://dx.doi.org/10.3390/w11030421.

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The aquifer heterogeneity is often simplified while conceptualizing numerical model due to lack of field data. Conducting field measurements to estimate all the parameters at the aquifer scale may not be feasible. Therefore, it is essential to determine the most significant parameters which require field characterization. For this purpose, the sensitivity analysis is performed on aquifer parameters, viz., anisotropic hydraulic conductivity, effective porosity and longitudinal dispersivity. The results of the sensitivity index and root mean square deviation indicated, that the longitudinal dispersivity and anisotropic hydraulic conductivity are the sensitive aquifer parameters to evaluate seawater intrusion in the study area. The sensitive parameters are further characterized at discrete points or at local scale by using regression analysis. The longitudinal dispersivity is estimated at discrete well points based on Xu and Eckstein regression formula. The anisotropic hydraulic conductivity is estimated based on established regression relationship between hydraulic conductivity and electrical resistivity with R2 of 0.924. The estimated hydraulic conductivity in x and y-direction are upscaled by considering the heterogeneous medium as statistically homogeneous at each layer. The upscaled model output is compared with the transversely isotropic model output. The bias error and root mean square error indicated that the upscaled model performed better than the transversely isotropic model. Thus, this investigation demonstrates the necessity of considering spatial heterogeneous parameters for effective modelling of the seawater intrusion in a layered coastal aquifer.

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Sola, F., A. Vallejos, L. Daniele et A. Pulido-Bosch. « Identification of a Holocene aquifer–lagoon system using hydrogeochemical data ». Quaternary Research 82, n^o 1 (juillet 2014) : 121–31. http://dx.doi.org/10.1016/j.yqres.2014.04.012.

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AbstractThe hydrogeochemical characteristics of the Cabo de Gata coastal aquifer (southeastern Spain) were studied in an attempt to explain the anomalous salinity of its groundwater. This detritic aquifer is characterised by the presence of waters with highly contrasting salinities; in some cases the salinity exceeds that of seawater. Multivariate analysis of water samples indicates two groups of water (G1 and G2). Group G1 is represented in the upper part of the aquifer, where the proportion of seawater varies between 10 and 60%, whilst G2 waters, taken from the lower part of the aquifer, contain 60−70% seawater. In addition, hydrogeochemical modelling was applied, which reveals that the waters have been subject to evaporation between 25 and 35%. There was a good agreement between the modelled results and the observed water chemistry. This evaporation would have occurred during the Holocene, in a coastal lagoon environment; the resulting brines would have infiltrated into the aquifer and due to their greater density, sunk towards the impermeable base. The characteristics of this water enabled us to reconstruct the interactions that must have occurred between the coastal aquifer and the lagoon, and to identify the environmental conditions that prevailed in the study area during the Middle Holocene.

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Han, Zheng, Wenxi Lu, Yue Fan, Jin Lin et Qian Yuan. « A surrogate-based simulation–optimization approach for coastal aquifer management ». Water Supply 20, n^o 8 (15 octobre 2020) : 3404–18. http://dx.doi.org/10.2166/ws.2020.259.

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Abstract This study proposed a pumping-injection (P-I) groundwater management strategy based on a simulation–optimization (S-O) framework to mitigate seawater intrusion (SI). The methodology was applied to a real case in Longkou, China. A three-dimensional variable-density groundwater simulation model was established to simulate and predict the SI process. In the S-O framework, while solving the optimization model, it is required to call the simulation model thousands of times, which leads to enormous computational load. In this case, the Kriging and support vector regression (SVR) surrogate models were established for the simulation model respectively. Furthermore, the ensemble surrogate modeling technique was applied to construct the Kriging-SVR ensemble surrogate model. The most accurate surrogate model was selected as the substitute for the simulation model, saving considerable computing costs. The results show that the ensemble surrogate model performs better than the stand-alone surrogate models in accuracy, indicating that combining stand-alone surrogate models is a potential modeling method for the surrogate model of the variable-density groundwater simulation model. By solving the optimization model, the optimal pumping and injection schemes under different scenarios were obtained. The optimization results demonstrate that the proposed methodology is effective and stable in coastal groundwater management.

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Song, Jian, Yun Yang, Jianfeng Wu, Jichun Wu, Xiaomin Sun et Jin Lin. « Adaptive surrogate model based multiobjective optimization for coastal aquifer management ». Journal of Hydrology 561 (juin 2018) : 98–111. http://dx.doi.org/10.1016/j.jhydrol.2018.03.063.

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Malama, Bwalya, Devin Pritchard-Peterson, John J. Jasbinsek et Christopher Surfleet. « Assessing Stream-Aquifer Connectivity in a Coastal California Watershed ». Water 13, n^o 4 (5 février 2021) : 416. http://dx.doi.org/10.3390/w13040416.

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We report the results of field and laboratory investigations of stream-aquifer interactions in a watershed along the California coast to assess the impact of groundwater pumping for irrigation on stream flows. The methods used include subsurface sediment sampling using direct-push drilling, laboratory permeability and particle size analyses of sediment, piezometer installation and instrumentation, stream discharge and stage monitoring, pumping tests for aquifer characterization, resistivity surveys, and long-term passive monitoring of stream stage and groundwater levels. Spectral analysis of long-term water level data was used to assess correlation between stream and groundwater level time series data. The investigations revealed the presence of a thin low permeability silt-clay aquitard unit between the main aquifer and the stream. This suggested a three layer conceptual model of the subsurface comprising unconfined and confined aquifers separated by an aquitard layer. This was broadly confirmed by resistivity surveys and pumping tests, the latter of which indicated the occurrence of leakage across the aquitard. The aquitard was determined to be 2–3 orders of magnitude less permeable than the aquifer, which is indicative of weak stream-aquifer connectivity and was confirmed by spectral analysis of stream-aquifer water level time series. The results illustrate the importance of site-specific investigations and suggest that even in systems where the stream is not in direct hydraulic contact with the producing aquifer, long-term stream depletion can occur due to leakage across low permeability units. This has implications for management of stream flows, groundwater abstraction, and water resources management during prolonged periods of drought.

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Pandian, Rajaveni Sundara, Indu Sumadevi Nair et Elango Lakshmanan. « Finite element modelling of a heavily exploited coastal aquifer for assessing the response of groundwater level to the changes in pumping and rainfall variation due to climate change ». Hydrology Research 47, n^o 1 (16 mai 2015) : 42–60. http://dx.doi.org/10.2166/nh.2015.211.

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Coastal aquifers are always under threat of seawater intrusion due to over-extraction of groundwater. The objective here is to assess aquifer response to variation in pumping and rainfall recharge due to projected climate change by groundwater modelling in a heavily exploited aquifer. Finite element groundwater flow modelling was carried out from March 1988 to December 2030 using FEFLOW software. Steady state calibration was done to match observed and simulated groundwater head by varying aquifer parameters within the allowable range. Transient state calibration was carried out during the period March 1988 to December 2002. The calibrated model was validated by comparing the simulated and observed groundwater head from January 2003 to December 2012. Groundwater head was predicted for a period until 2030 under eight different scenarios of changes in pumping and rainfall recharge. This prediction indicated that 10% increase of recharge and 10% decrease of pumping causes 3 m and 6 m increase in groundwater head in upper and lower aquifers, respectively, by the end of 2030. Groundwater recharge can be increased by rejuvenation of existing surface water bodies, check dams and construction of proposed check dams. Thus, increase of groundwater recharge and decrease in well field pumping is achievable to restore this heavily exploited coastal aquifer in another 20 years.

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Simpson, Trevor B., Ian P. Holman et Ken R. Rushton. « Understanding and modelling spatial drain-aquifer interactions in a low-lying coastal aquifer-the Thurne catchment, Norfolk, UK ». Hydrological Processes 25, n^o 4 (7 septembre 2010) : 580–92. http://dx.doi.org/10.1002/hyp.7845.

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Al-Maktoumi, Ali, Slim Zekri, Mustafa El-Rawy, Osman Abdalla, Rashid Al-Abri, Chefi Triki et Mohammad Reza Bazargan Lari. « Aquifer storage and recovery, and managed aquifer recharge of reclaimed water for management of coastal aquifers ». DESALINATION AND WATER TREATMENT 176 (2020) : 67–77. http://dx.doi.org/10.5004/dwt.2020.25499.

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Melloul, A., et M. Collin. « Water Quality Factor Identification by the “Principal Components” Statistical Method ». Water Science and Technology 24, n^o 11 (1 décembre 1991) : 41–50. http://dx.doi.org/10.2166/wst.1991.0335.

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This paper proposes the means of using the “Principal Components” statistical method for identifying relevant groups of water and the factors that bring about a change in their quality. The major advantage of this method lies in its suitability for simultaneous analysis of a great number of variables and observations.It is here being applied for the investigation of Dan metropolitan region of Israel's Coastal Plain. The various parameters involved include major ions as well as the physical factors of depth to the water table, distance from the sea, and aquifer recharge. Results include:–the identification of two major groups of water: low salinity, calcium bicarbonate water occurring in the phreatic portion of the Coastal aquifer; and more saline, sodium chloride water characterizing the neighboring Cenomanian aquifer and the confined portions of the Coastal aquifer;–influence by distance from the sea, depth to water table, and aquifer lithology on the major water input sources, such as rain, injection water, waste water, irrigation, etc.–affect by such lithological factors as clay lenses which contribute to water quality changes as indicated by disequilibrium in several ionic ratios upon water resource management; and–clear visualization on the same graph of evolutionary alteration in specific ion content with time.

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Stoffner, Fabian, et Mustapha Mimouni. « Application of Sentinel 2 Satellite Imagery for Sustainable Groundwater Management in Agricultural Areas—Chtouka Aquifer, Morocco ». Quaternary 4, n^o 4 (31 octobre 2021) : 35. http://dx.doi.org/10.3390/quat4040035.

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In semi-arid regions that are characterized by large agricultural activities, a high volume of water is needed to cover the water requirements for agricultural production. Due to low precipitation and the associated limited availability of surface water, aquifers often represent the main source of irrigation water in these regions. Especially in coastal aquifers, high groundwater abstraction rates may change the flow dynamics of the aquifer and may lead to saltwater intrusion. In this study, within the framework of German–Moroccan international cooperation, the agricultural areas for the summer period 2019 of the Chtouka coastal aquifer in southern Morocco are classified using optical and multi-spectral Sentinel 2 data. Based on the developed land use maps, the groundwater abstraction for irrigation is then quantified by referring to local farmers’ irrigation practices. Following this approach, the total amount of groundwater abstraction is estimated at 157 million m3 for the summer period 2019 in the Chtouka aquifer.

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Zamrsky, Daniel, Gualbert H. P. Oude Essink et Marc F. P. Bierkens. « Estimating the thickness of unconsolidated coastal aquifers along the global coastline ». Earth System Science Data 10, n^o 3 (3 septembre 2018) : 1591–603. http://dx.doi.org/10.5194/essd-10-1591-2018.

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Abstract. Knowledge of aquifer thickness is crucial for setting up numerical groundwater flow models to support groundwater resource management and control. Fresh groundwater reserves in coastal aquifers are particularly under threat of salinization and depletion as a result of climate change, sea-level rise, and excessive groundwater withdrawal under urbanization. To correctly assess the possible impacts of these pressures we need better information about subsurface conditions in coastal zones. Here, we propose a method that combines available global datasets to estimate, along the global coastline, the aquifer thickness in areas formed by unconsolidated sediments. To validate our final estimation results, we collected both borehole and literature data. Additionally, we performed a numerical modelling study to evaluate the effects of varying aquifer thickness and geological complexity on simulated saltwater intrusion. The results show that our aquifer thickness estimates can indeed be used for regional-scale groundwater flow modelling but that for local assessments additional geological information should be included. The final dataset has been made publicly available (https://doi.pangaea.de/10.1594/PANGAEA.880771).

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D’ozouville, Noémi, Sophie Violette, Nathalie Gassama, Aline Dia et Nathalie Jendrzejewski. « Origin and modelling of water salinization in a coastal aquifer of the Bay of Bengal : The Kaluvelly watershed, Tamil Nadu, India ». Bulletin de la Société Géologique de France 177, n^o 6 (1 novembre 2006) : 333–45. http://dx.doi.org/10.2113/gssgfbull.177.6.333.

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Abstract Over-pumping of the Vanur sandstone aquifer has led to a lowering of the piezometric surface and degradation of water quality through increased salinization. This aquifer salinization is a good example of many similar problems in India and other parts of the world. The Vanur Formation is the main aquifer of a multilayered system bordered by the sea on the eastern side and partly overlaid by the brackish waters of the Kaluvelly swamp in the north. The origin of the salinity, which apparently is not simply seawater intrusion, and its dynamics are examined, using chemical and isotopic tools together with 1D hydrological modelling of the movement of the seawater/fresh water interface. The content of major elements and some trace elements as well as isotopic ratios (18O/16O, D/H and 87Sr/86Sr) were measured in groundwater, surface and rainwater during five sampling surveys (January 1999 to October 2001). Available data on rainfall, piezometric and hydrogeologic records were used. We identified human contamination by F, Li in parts of the aquifer, which invalidated their use as tracers. The chemical composition of water from the Vanur aquifer shows a classical chemical evolution from the recharge area to the deeper confined area, consisting in increased water-rock interaction and a subsequent increase of solute species. However, the range of major compound concentration ratios for some wells does not follow this general trend. The non-consistent points are located in the most depressed area of the aquifer (−20 m amsl in June 2000), except in the north where the brackish water of the Kaluvelly swamps seems to enter the aquifer. In the depressed area, the sulphate signature corresponds to a mixing with a mineralized and sulphate-rich water body, likely to be Ramanathapuram sandstone water. It is due to the upward leakage from this underlying formation. A seasonal evaporation signature recorded by stable isotopes (δ18O, δD) suggests the addition of return irrigation flow. The 1D hydrodynamical model of the sea-water/fresh water movement was built with the available geological and hydraulic data. Hydrodynamic calculations show that seawater intrusion can be expected to occur within 3 to 20 years after the year 2000, depending on the value of unknown parameters (porosity) or boundary conditions (recharge, pumped volume). But we cannot rule out that a lithologic or tectonic barrier prevent any seawater intrusion inland; future geological investigation has to be done to confirm or infirm this hypothesis.

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Al-Juaidi, Ahmed E., Jagath J. Kaluarachchi et Attia I. Mousa. « Hydrologic-Economic Model for Sustainable Water Resources Management in a Coastal Aquifer ». Journal of Hydrologic Engineering 19, n^o 11 (novembre 2014) : 04014020. http://dx.doi.org/10.1061/(asce)he.1943-5584.0000960.

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Dreizis, Y. I. « Modelling of water quality management in the sea coastal zone ». E3S Web of Conferences 224 (2020) : 02001. http://dx.doi.org/10.1051/e3sconf/202022402001.

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Coastal territories are one of the most dynamically developing regions. Sea resorts focused on recreational and tourist activities are developing especially quickly. For such territories, their ecological status, especially the quality of coastal zone water resources, plays an important role in their sustainable development. Analysis of physical factors of water exchange and assessment of water resources quality of the coastal zone of the sea, including in closed and semi-enclosed water areas, was carried out. It has been shown that water exchange is the most important factor in the management of the quality of marine waters of partially enclosed coastal areas. 0-dimensional and system-dynamic models were used to analyze water exchange in the coastal zone of the sea. Results of studies made it possible to assess the circulation of coastal marine waters and the change in certain indicators of the quality of water resources, including in the presence of various coastal protection construction.

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Herrera-Franco, Gricelda, Paúl Carrión-Mero, Maribel Aguilar-Aguilar, Fernando Morante-Carballo, María Jaya-Montalvo et M. C. Morillo-Balsera. « Groundwater Resilience Assessment in a Communal Coastal Aquifer System. The Case of Manglaralto in Santa Elena, Ecuador ». Sustainability 12, n^o 19 (8 octobre 2020) : 8290. http://dx.doi.org/10.3390/su12198290.

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Resilience has several meanings, among them the ability to overcome difficulty and return to the state of providing service, even if the initial conditions change. Assessing resilience in an ecosystem, or any system, requires a concise methodology with standard variables and parameters. The current challenge presented by coastal areas is focused on overcoming problems related to the water supply through correct management. This paper aims to evaluate the communal coastal aquifer system with a matrix for assessing water resilience based on indicators in the Sustainable Development Goals (SDGs) in a socio-hydrological framework and the four axes of development (political, social, environmental, and cultural), to promote the development of new strategies for water sustainability. The method is based on (i) political, economic, social, environmental, and even cultural aspects involved in sustainable water management and (ii) the groundwater resilience assessment method (GRAM) design. The GRAM is used for a quasi-quantitative assessment of the resilience in a communal coastal aquifer system. This method was applied to the Manglaralto community; the results show a highly resilient groundwater system (62.33/100 points). Representatives of the community have achieved appropriate use, management, and conservation of the water resource by applying water harvesting and other technical criteria. Hence, they have avoided aquifer overexploitation and provided water to the community.

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Majour, Habiba, Azzedine Hani et Larbi Djabri. « Salinity and modelling of the Annaba aquifer system, North-East of Algeria ». Journal of Water and Land Development 37, n^o 1 (1 juin 2018) : 113–20. http://dx.doi.org/10.2478/jwld-2018-0030.

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Abstract The potentiometer area in the Annaba basin, covering an area of 264 km2, has declined considerably since 1995. The analysis of the chronological hydrographs (1991–2009) of the piezometric observations shows that this decline is related to about twenty years (20 years) drought that began in 1991. To synthesize hydrological data and study regional changes in aquifer interactions caused by changes in discharge, and determine the contamination of aquifers by salty intrusion in coastal areas, and making forecasts by the year 2023, a multi-layered transient model as well as a solute transport model has been developed. The groundwater flow was modelled using the finite difference method with a horizontal dimension of 500 × 500 m for the cells. The model consists of two layers, the first corresponding to the alluvial phreatic aquifer and the second to the deep confined aquifer, and is calibrated against the steady state groundwater heads recorded before 1996. Model verification was done by history matching over the period 1991–2009. Under steady-state conditions, the correspondence between simulated and observed water levels is generally good (average difference of 0.4 m). For the deep aquifer, the simulated time-series hydrographs closely match the recorded hydrographs for most of the observation wells. For the alluvial aquifer, the recorded hydrographs cover only a short time period, but they are reproduced. The model indicates that groundwater pumping induced a decrease in natural discharge, a downward leakage in most of the basin and a continual water-level decline. The model has also been applied to the analysis of recharge impact. Simulating the behaviour of the system over the period 1991–2009 without pumping indicated small changes in hydraulic head. These results show that the groundwater reservoir has a low recharge, but excellent hydraulic properties. A solute-transport model was used to study aquifer contamination from salty intrusion in coastal sectors; it was extended to the year 2023 by simulating an optimistic hypothesis that maintains present pumping until 2023. The model indicates that the head decrease of the alluvial phreatic and deep confined aquifers will be 4 m and 5 m respectively. The solute concentration in the deep confined aquifer will increase from 1 gꞏdm−3 (prior 2009) to 5 gꞏdm−3 in 2023.

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Nativ, Ronit, et Noam Weisbrod. « Management of a multilayered Coastal aquifer ? An Israeli case study ». Water Resources Management 8, n^o 4 (1994) : 297–311. http://dx.doi.org/10.1007/bf00872403.

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Lazarova, Valentina, Yves Emsellem, Julie Paille, Karl Glucina et Philippe Gislette. « Water quality management of aquifer recharge using advanced tools ». Water Science and Technology 64, n^o 5 (1 septembre 2011) : 1161–68. http://dx.doi.org/10.2166/wst.2011.418.

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Managed aquifer recharge (MAR) with recycled water or other alternative resources is one of the most rapidly growing techniques that is viewed as a necessity in water-short areas. In order to better control health and environmental effects of MAR, this paper presents two case studies demonstrating how to improve water quality, enable reliable tracing of injected water and better control and manage MAR operation in the case of indirect and direct aquifer recharge. Two water quality management strategies are illustrated on two full-scale case studies, including the results of the combination of non conventional and advanced technologies for water quality improvement, comprehensive sampling and monitoring programs including emerging pollutants, tracer studies using boron isotopes and integrative aquifer 3D GIS hydraulic and hydrodispersive modelling.

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Carrión-Mero, Paúl, F. Javier Montalván, Fernando Morante-Carballo, Javier Heredia, F. Javier Elorza, Joselyne Solórzano et Héctor Aguilera. « Hydrochemical and Isotopic Characterization of the Waters of the Manglaralto River Basin (Ecuador) to Contribute to the Management of the Coastal Aquifer ». Water 13, n^o 4 (19 février 2021) : 537. http://dx.doi.org/10.3390/w13040537.

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Coastal aquifers are strategic and fundamental in the development of touristic areas. The coastal aquifer within the Manglaralto River Basin in Ecuador is essential, as it is the only source of water supply for a large part of the northern part of the Santa Elena province. It is a semi-arid region where high volumes of water are pumped from the aquifer, causing a significant drawdown of groundwater levels, thus affecting the water quality. This work aims to characterize the characteristics of groundwater in the coastal aquifer using hydrochemistry and stable isotopes to propose a hydrogeological conceptual model. The methodology for determining the chemical and isotopic characteristics of groundwater follows the following scheme: (i) studies of ionic concentrations using the Piper diagram, (ii) assessment of the origin of salinity through the Cl/Br ratio, the presence of seawater intrusion through the Hydrochemical Facies Evolution Diagram HFE-D, (iii) characterization of precipitation events using stable isotopes (18O and 2H), and, (iv) development of a hydrogeological conceptual model of the study area. The results indicate that in the basin there are mixing processes of the existing water in the aquifer with recharge water, direct cation exchange processes in the freshening process during recharge, and evaporation in the unsaturated zone. A conceptual model of the flow system in the basin is built, based on the mentioned processes. The main conclusions are: seawater intrusion is present in the areas of the wells located closest to the coast, urban activity through septic tanks is affecting the quality of the aquifer, and rainfall is highly relevant in the different hydrochemical and isotopic processes that operate in the basin.

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Cherubini, C., et N. Pastore. « Critical stress scenarios for a coastal aquifer in southeastern Italy ». Natural Hazards and Earth System Sciences 11, n^o 5 (16 mai 2011) : 1381–93. http://dx.doi.org/10.5194/nhess-11-1381-2011.

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Abstract. Over the last years the sustainable management of coastal water resources has become strategic, especially in southern Salento Peninsula (Apulia), where mal-performing management strategies adopted, together with the vulnerability of the hydrogeological system, have given rise to the deterioration of groundwater quality due to saltwater intrusion. In the study area there is the presence of multilevel shallow aquifer and a deep aquifer that interact by means of faults. The geological system is highly vulnerable to seawater intrusion so there is the need to adopt management strategies to avoid seawater intrusion phenomena. Nevertheless there is a lack of studies that analyze the methodology for the correct exploitation if the water resource in order to avoid further intrusion phenomena. This paper combines a density-driven, flow numerical model (Seawat v.4) with a fault conceptual and hydrologic model to simulate saltwater intrusion phenomenon in the deep as well as in the shallow aquifer of the Salento area. By means of the individuation of an indicator parameter of groundwater quality, it has been possible to simulate different scenarios of exploitation and therefore to define critical stress scenarios for both aquifers. The results show that the deep aquifer is more vulnerable than the shallow one, which means that in the former, in order not to reach conditions of contamination, a lower density of wells is necessary than in the latter. The reduction of well density coupled with the artificial recharge of freshwater into the aquifer may be proposed as a solution strategy to protect the aquifer. Therefore, future developments of the present study will be represented by the simulation of different scenarios of recharging to inhibit the saltwater intrusion front further inland. The proposed methodology and its future developments can represent an empirical tool to provide preliminary guidelines for long-term groundwater management in coastal aquifers.

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Bocanegra, Emilia, Gerson Cardoso Da Silva, Emilio Custodio, Marisol Manzano et Suzana Montenegro. « State of knowledge of coastal aquifer management in South America ». Hydrogeology Journal 18, n^o 1 (10 octobre 2009) : 261–67. http://dx.doi.org/10.1007/s10040-009-0520-5.

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Articles de revues sur le sujet « Water management, MODELLING, COASTAL AQUIFER »

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