scholarly journals Proposing the Optimum Withdrawing Scenarios to Provide the Western Coastal Area of Port Said, Egypt, with Sufficient Groundwater with Less Salinity

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3359
Author(s):  
Mohamed Abdelfattah ◽  
Heba Abdel-Aziz Abu-Bakr ◽  
Ahmed Gaber ◽  
Mohamed H. Geriesh ◽  
Ashraf Y. Elnaggar ◽  
...  

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.

2017 ◽  
Vol 50 (2) ◽  
pp. 798 ◽  
Author(s):  
I. Lappas ◽  
A. Kallioras ◽  
F. Pliakas ◽  
Th. Rondogianni

Groundwater resources assessment has resulted in development of models that help identify the vulnerable zones. This paper presents a GIS-based hydrogeological index, named GALDIT, aiming at the assessment of aquifer vulnerability to seawater intrusion in Atalanti coastal aquifer, Central-Eastern Greece. The above acronym is formed from the most important factors controlling seawater intrusion, that is, four intrinsic hydrogeological parameters, one spatial parameter and one boundary parameter including Groundwater occurrence (aquifer type), Aquifer hydraulic conductivity, depth to groundwater Level above the sea (hydraulic head), Distance from the shore, Impact of seawater intrusion and aquifer’s Thickness. These factors nclude the basic requirements needed to assess the general salinization potential of each hydrogeological setting. Each parameter is evaluated with respect to the other to determine the relative importance of each factor. GALDIT model is described to assess and quantify the significance of vulnerability to seawater intrusion due to excessive groundwater withdrawals. Different thematic maps are prepared for seawater intrusion indicators and overlaid to develop the final vulnerability map. The derived map can be used as a tool for coastal groundwater resources management and areas’ determination of potential saltwater intrusion since the result of GALDIT ndex is classified based on vulnerability rate.


2015 ◽  
Vol 47 (1) ◽  
pp. 89-103 ◽  
Author(s):  
M. Shapouri ◽  
L. Cancela da Fonseca ◽  
S. Iepure ◽  
T. Stigter ◽  
L. Ribeiro ◽  
...  

We examined the variation of stygofauna composition collected in wells, along a gradient in groundwater salinity/conductivity in a coastal aquifer from southern Portugal. The studied coastal aquifer is considered vulnerable to salinization due to seawater intrusion, caused by overexploitation of the aquifer. Knowing the response of the stygofauna species to present levels of groundwater salinity makes it possible to understand and measure the effects of saltwater intrusion on stygofauna, rendering them potential bioindicators of this environmental pressure. Biotic and abiotic sampling was conducted in six shallow wells located in the fresh–saltwater interface of the Arade estuary along the salinity gradient established in the groundwater from the estuary to inland locations (microSiemens/cm). Groundwater salinity was highly correlated with taxa distribution. The stygobites Eucyclops hadjebensis and Acanthocyclops sensitivus, the cosmopolitan Megacyclops viridis and Cypria ophtalmica were particularly associated with low-salinity conditions, whereas Eucyclops graeteri, Megacyclops brachypus and Daphnia pulicaria were related to high-salinity waters. Multivariate analyses indicated that stygofauna assemblages varied significantly with location. We suggest that stygofauna composition and structure can be a useful complementing tool for monitoring seawater intrusion into coastal aquifers, where reduction or deterioration in groundwater resources is predicted.


2020 ◽  
Vol 79 (22) ◽  
Author(s):  
Sun Woo Chang ◽  
Il-Moon Chung ◽  
Min-Gyu Kim ◽  
Bisrat Ayalew Yifru

AbstractJeju Island is the largest island in South Korea. Recently, extensive groundwater abstraction has been reported from the shallow aquifer in the northeast region of the island. This study simulated the freshwater resources of the aquifer to estimate the sustainability of groundwater use on Jeju Island in terms of its vulnerability to seawater intrusion. Three-dimensional finite-difference numerical groundwater models were simulated using the MODFLOW-family code SEAWAT. Precise and recent groundwater level and multi-depth salinity data obtained from the study site were used for model calibration; the simulated results showed good agreement with the observed data. SEAWAT was used to delineate the current seawater-freshwater interface to quantitatively estimate the coastal fresh groundwater resources. Future stress scenarios were also simulated in response to increased pumping and various changes in the recharge. The results showed that current groundwater use in the coastal aquifer did not induce seawater intrusion in the coastal aquifer, but seawater intrusion will occur if the dry season continues for the next ten years. The vulnerability assessment based on the predicted groundwater levels and ion concentrations using numerical simulations suggests future vulnerability in the aquifer; therefore, continuous assessment and visualization of the aquifer sustainability is vital. Future projections by the integrated SEAWAT simulation and GALDIT assessment showed that an increase in groundwater pumping may escalate the vulnerability status of coastal groundwater resources from moderate to high in some areas of the study site, by inducing lateral seawater intrusion in deeper areas of the unconfined aquifer.


2020 ◽  
Vol 28 (6) ◽  
pp. 2085-2103 ◽  
Author(s):  
Mahdieh Dibaj ◽  
Akbar A. Javadi ◽  
Mohammad Akrami ◽  
Kai-Yuan Ke ◽  
Raziyeh Farmani ◽  
...  

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.


2016 ◽  
Vol 18 (1) ◽  
pp. 185-196 ◽  

<div> <p>Groundwater is one of the major parameters in maintaining ecology in many regions. As climate is one of the main factors which affects groundwater resources, the main objective of the present study is to assess the impact of rainfall changes on the groundwater system by projecting the future changes in the 21<sup>st</sup> century (2021-2050 and 2071-2100). For this reason, the RegCM3 climate model precipitation data, which showed a reduction in rainfall, was entered in the steady-state groundwater flow model MODFLOW for the case study of a coastal aquifer in the eastern part of the Thermaikos Gulf (North Greece). The uprising urbanization in combination with the intensive cultivation have led to the overexploitation of the coastal aquifer and seawater intrusion. The groundwater flow simulation by using the MODFLOW code indicates a negative water budget and estimates the quantities of the seawater intrusion. According to the RegCM3 climate model, the precipitation reduction is estimated to be 4% during the period of 2021-2050, while the precipitation decrease is expected to be 22% during the period of 2071-2100. Furthermore, the natural recharge of the coastal aquifer is expected to be influenced by the precipitation reduction. Finally, the seawater intrusion amounts are expected to increase during these future periods and more specifically during the second period of 2071-2100.</p> </div> <p>&nbsp;</p>


2017 ◽  
Vol 50 (2) ◽  
pp. 865 ◽  
Author(s):  
A. Mitropapas ◽  
I. Koumantakis ◽  
E. Vasileiou ◽  
M. Perdikaki ◽  
A. Kallioras

Intense abstraction of groundwater resources in the coastal aquifer system of Argolis is investigated since the late 1950’s. The increasing water demands due to the agricultural development of the area (mainly citrus trees) during the last years, in combination with the touristic growth, has led to the overexploitation of groundwater resources of the coastal aquifer system of Argolis. This paper presents the piezometric conditions in the plain of Argos during the period between 1986 and 2014, analysing the fluctuations of groundwater levels and highlighting the problem of seawater intrusion in the study area. In October 2014, measurements were made in app. 160 wells and drills which are located within the boundaries of the granular aquifer of the study area. Selected piezometric maps are presented, which demonstrate the problem of overexploitation of groundwater in the plain of Argos.


2020 ◽  
Vol 28 (8) ◽  
pp. 2635-2656
Author(s):  
Samson Oiro ◽  
Jean-Christophe Comte ◽  
Chris Soulsby ◽  
Alan MacDonald ◽  
Canute Mwakamba

AbstractThe Nairobi volcano-sedimentary regional aquifer system (NAS) of Kenya hosts >6 M people, including 4.7 M people in the city of Nairobi. This work combines analysis of multi-decadal in-situ water-level data with numerical groundwater modelling to provide an assessment of the past and likely future evolution of Nairobi’s groundwater resources. Since the mid-1970s, groundwater abstraction has increased 10-fold at a rate similar to urban population growth, groundwater levels have declined at a median rate of 6 m/decade underneath Nairobi since 1950, whilst built-up areas have increased by 70% since 2000. Despite the absence of significant trends in climatic data since the 1970s, more recently, drought conditions have resulted in increased applications for borehole licences. Based on a new conceptual understanding of the NAS (including insights from geophysics and stable isotopes), numerical simulations provide further quantitative estimates of the accelerating negative impact of abstraction and capture the historical groundwater levels quite well. Analysis suggests a groundwater-level decline of 4 m on average over the entire aquifer area and up to 46 m below Nairobi, net groundwater storage loss of 1.5 billion m3 and 9% river baseflow reduction since 1950. Given current practices and trajectories, these figures are predicted to increase six-fold by 2120. Modelled future management scenarios suggest that future groundwater abstraction required to meet Nairobi projected water demand is unsustainable and that the regional anthropogenically-driven depletion trend can be partially mitigated through conjunctive water use. The presented approach can inform groundwater assessment for other major African cities undergoing similar rapid groundwater development.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1952
Author(s):  
Subrata Halder ◽  
Lingaraj Dhal ◽  
Madan K. Jha

Providing sustainable water supply for domestic needs and irrigated agriculture is one of the most significant challenges for the current century. This challenge is more daunting in coastal regions. Groundwater plays a pivotal role in addressing this challenge and hence, it is under growing stress in several parts of the world. To address this challenge, a proper understanding of groundwater characteristics in an area is essential. In this study, spatio-temporal analyses of pre-monsoon and post-monsoon groundwater-levels of two coastal aquifer systems (upper leaky confined and underlying confined) were carried out in Purba Medinipur District, West Bengal, India. Trend analysis of seasonal groundwater-levels of the two aquifers systems was also performed using Mann-Kendall test, Linear Regression test, and Innovative Trend test. Finally, the status of seawater intrusion in the two aquifers was evaluated using available groundwater-quality data of Chloride (Cl−) and Total Dissolve Solids (TDS). Considerable spatial and temporal variability was found in the seasonal groundwater-levels of the two aquifers. Further, decreasing trends were spotted in the pre-monsoon and post-monsoon groundwater-level time series of the leaky confined and confined aquifers, except pre-monsoon groundwater-levels in Contai-I and Deshpran blocks, and the post-monsoon groundwater-level in Ramnagar-I block for the leaky confined aquifer. The leaky confined aquifer in Contai-I, Contai-III, and Deshpran blocks and the confined aquifer in Nandigram-I and Nandigram-II blocks are vulnerable to seawater intrusion. There is an urgent need for the real-time monitoring of groundwater-levels and groundwater quality in both the aquifer systems, which can ensure efficient management of coastal groundwater reserves.


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