Nile Delta Aquifer Research Articles

Innovative management strategies for groundwater logging in Aswan city and maximization of its benefits using modeling techniques

Groundwater levels vary from region to another and sometimes in different zones in the same country due to different boundary conditions and extraction rates. Therefore, understanding intricate aquifer systems and predicting how they will react to hydrological changes require the use of groundwater models. In Egypt, the groundwater levels in the Nile Delta aquifer decrease causing problems to the delta ecosystem while it is rising in Aswan area due to the presence of Nasser Lake causing several damages to the city’s buildings and infrastructures. In order to maximize its benefits and lessen the harm brought on by inadequate groundwater management in the city of Aswan, the height of the groundwater level in that city was examined, appraised, and groundwater management scenarios were established in this study. To achieve the objectives of the study, a simulation of Aswan aquifer’s groundwater system is built based on a quasi-three-dimensional transient groundwater flow model using MODFLOW. The model was calibrated and verified. Four management scenarios are tested. The fifth scenario, in this scenario, the four scenarios combined together at the same time and with the same conditions and ratios were proposed to be implemented. The results of the proposal to implement the four scenarios together showed that the rates of decline in groundwater levels in the last stage will be 12.44%. The study results reveal that a better understanding of the simulated long-term average spatial distribution of water balance components is useful for managing and planning the available water resources in the Aswan aquifer.

Optimizing Irrigation Systems for Water Efficiency and Groundwater Sustainability in the Coastal Nile Delta

This study investigates the replacement of traditional surface irrigation methods with modern irrigation systems (MIS) including horizontal sprinkler, central pivot, surface drip, and subsurface drip aimed at improving water efficiency in the Nile Delta, Egypt. The primary objectives were to determine the optimal agricultural area for implementing MIS and to assess the effects of these systems on groundwater quantity and quality in the region. To achieve this, the LINDO software was employed to optimize land allocation for each irrigation method. At the same time, the SEAWAT code was utilized to simulate saltwater intrusion (SWI) in the Nile Delta aquifer. The transition from traditional surface irrigation to MIS resulted in significant water savings, reaching 2.15 × 10^9 m³. However, groundwater modeling indicated a decrease in groundwater levels, leading to an 8 % increase in aquifer salinity due to reduced infiltration of recharge water. These findings underscore the urgent need to revise outdated irrigation practices and enhance water management strategies in the Nile Delta to mitigate salinity issues in coastal aquifers. This research's outcomes are crucial for decision-makers and stakeholders in selecting appropriate irrigation methods, particularly in arid and semi-arid regions, to ensure sustainable water use and agricultural productivity.

Hydrologic source identification using stable isotope ratios of bottled drinking water in Egypt

A convenient way to understand hydrologic source identification is to make use of a suitable tracer. Isotopes of oxygen and hydrogen provide that opportunity since the isotope ratios of the primary source, precipitation, can be modified by post precipitation processes. This approach has been tested by carrying out a comprehensive isotope ratios investigation of domestic and imported bottled water sourced and distributed across Egypt. Our collection of bottled water includes 33 samples distributed under 27 distinct brands. We compare the isotope ratios of the bottled water with the isotope ratios of the reported natural water source of this water. The bottled water isotope ratios preserve information about the water sources from which they were derived. The measured oxygen and hydrogen ratios of the studied bottled water samples range from −11.51‰ to 2.94‰, with an average value of −1.89‰ for δ18O and from −81.69‰ to 23.94‰, with an average value of −9.54‰ for δ2H. The observed variability of isotope ratios in the bottled water falls within the span of the natural groundwater resources in Egypt, such as shallow and deep groundwater aquifers as well as claimed non-Egyptian sources. In general, the bottled water samples in the data set can be divided into four distinct groups based on their isotope ratios. One group represents imported bottled water brands, and three groups include domestic brands. The first group represents the imported bottled water brands. Their measured isotopic compositions are similar to those of their claimed sources. The second group has the lowest δ18O and δ2H values and likely originated from the Nubian aquifer. The third and fourth groups appear to have been sourced from the Nile Valley and Delta aquifer. The third group isotopic content and d-excess values indicate a higher degree of mixing with evaporated return flow water. The results provided in this study indicate the diverse hydrogeology of the local bottled water brands. This promises extending the approach to several sites globally.

Assessing the impacts of canal rehabilitation and lining on groundwater conditions

ABSTRACT The Nile Delta aquifer stands as Egypt’s second primary freshwater source following the Nile River. Its replenishment deriveed from various sources, including the Nile branches, the surface irrigation networks, and the infiltration of excess irrigation water. The expanded demand for irrigation water causes water shortages at the canal tails of some irrigation canals across Egypt. Farmers have resorted to addressing this issue by illegally excavating shallow wells, employing them in times when surface water is inaccessible. Among the national action plans to improve water availability at canal tails is the lining of distributary canals. However, this intervention potentially obstructs the natural replenishment source of the Nile Delta aquifer, consequently contributing to the deterioration of groundwater quality. Hence, this research aims to evaluate the impacts of lining distributary canals on groundwater status through numerical modeling. Utilizing the MODFLOW package, the study determines the natural infiltration rates from the canals into the adjoining groundwater system. Two prevalent hydrological conditions in Egypt were selected for numerical modeling. The first case study focuses on a Canal, located in Qalyoubia governorate, represents the semi-confined aquifer conditions prevalent in the Nile Delta. The second case study is a Canal, situated in Sharqia governorate, represents the phreatic aquifer conditions present in the Nile Delta. Piezometers were implemented to determine the groundwater levels and for the calibration process. The calibrated models were employed to simulate the expected impacts of canal lining for each case and contrasted with pre-lining infiltration rates. Findings indicate that while canal lining effectively reduces water seepage into shallow groundwater in sandy soils, it is of little avail in clayey top soils. The research recommends implementing integrated water resource management to mitigate the possible impacts of lining. It also suggests prioritizing regular maintenance practices for canal linings, especially in areas with sandy soils.

Assessment of modern irrigation versus flood irrigation on groundwater potentiality in old clayey lands

Groundwater management in semiarid and arid regions, like northern Egypt, is essential for the sustainability of scarce resources through monitoring groundwater status and sources of recharge to the aquifer. In the Qalyubia Governorate, Nile Delta, Egypt, the study examined the recharge of groundwater in lands subject to flood irrigation and compared it with water-saving irrigation methods to detect how irrigation practices influence the potentiality of groundwater. A simulation of the two irrigation techniques, flood irrigation, and water-saving irrigation, was performed. Using GMS, simulations are done to calculate the water balance in the main 8 districts of Qalyubia Governorate. In comparison to flood irrigation, it was found that water-saving irrigation has less recharge intensity, which in turn causes a lowering in groundwater levels. The decline in groundwater table ranges between 10 and 50 cm. Modern irrigation influences the potentiality of the Nile Delta aquifer, which can’t be underestimated.

Hazards of sea level rise and dams built on the River Nile on water budget and salinity of the Nile Delta aquifer

Study regionThe Nile Delta region consists of flat, low-lying areas, where most areas are used for agriculture. It covers an area of 22,000 km2, which is 2.20% of the total area of Egypt. Study focusThis study evaluates the water budget and the salinity due to the Sea Level Rise (SLR) and the reduction in the river water flow caused by the Grand Ethiopian Renaissance Dam (GERD) using the numerical code SEAWAT. Three filling scenarios were considered for the GERD reservoir at elevations 600 m, 621 m, and 645 m above mean sea level (AMSL) for the storage volumes of 17 billion cubic meters (BCM) (scenarios #1), 37.30 BCM (scenarios #2), and 74 BCM (scenarios #3). The impact of these fillings scenarios was combined with SLR of 25 cm, and increasing the abstraction rates from the Nile Delta aquifer by 25%, 50%, and 100%, respectively. New hydrological insights for the regionThe study findings indicated that the SLR and the GERD reservoir filling with increasing pumping rates, especially during the filling periods, would influence the groundwater resources in the Nile Delta. The GERD reservoir filling could alter the freshwater, in which the aquifer salinity increased by 4.47%, 11.48%, and 29.99% for the three scenarios, respectively. The methodology and findings presented in this study might be useful for investing and comparing the impact of SLR and upstream dam projects on the downstream water budget and salinity at other coastal regions.

Assessment of Salt-Water Wedge in the Artesian Egyptian Nile Delta Aquifer Lands Using Remote Sensing and Geophysical Techniques.

Assessment of Salt-Water Wedge in the Artesian Egyptian Nile Delta Aquifer Lands Using Remote Sensing and Geophysical Techniques.

Mitigating seawater intrusion in coastal aquifers: Novel approach with treated wastewater injection and groundwater circulation

Seawater intrusion (SWI) is a natural phenomenon that negatively impacts the potability of groundwater and is expected to worsen with rising sea levels due to climate change. Artificial recharge of freshwater is a commonly-used remediation method to mitigate SWI and improve freshwater supply security in affected coastal aquifers. However, limited freshwater availability can limit the effectiveness of this approach. This study proposes a novel mitigation measure, called Inj-GCW, which combines the injection of reclaimed water with the use of groundwater circulation wells (GCW) to enhance the effectiveness of artificial recharge in controlling SWI. GCW is a dual-screened well with isolated screens that extract and inject groundwater into the aquifer. The performance of the proposed measure was quantitatively evaluated using an illustrative simplified unconfined coastal aquifer. Based on the findings, the design parameters were estimated for a field-scale case study of the Nile Delta aquifer (NDA), a large Mediterranean coastal aquifer in Egypt. The study adopts a future scenario that considers Sea-level rise due to climate change and projected population growth by 2100. Results demonstrate that introducing of GCWs into the saltwater wedge, along with injection, effectively retreated the saltwater wedge, due to enhanced velocity, seaward fluxes, and dilution of contamination. Inj-GCW measure led to an 8.9% reduction in SWI and a 5.2% decrease in aquifer salinity compared to the expected intrusion in 2100. Furthermore, the Inj-GCW measure resulted in a 2.2% higher repulsion rate and 0.3% reduction in total salt mass compared to injection alone. The Inj-GCW measure presents a promising solution to SWI challenges in the NDA and other coastal aquifers facing similar issues. The formation of a brackish water bubble at the injection well screen of the GCW and the generated vertical groundwater circulation cells acted as a hydraulic barrier and contributed to the proposed method effectiveness.

The impact of future hydrology stresses and climate change on submarine groundwater discharge in arid regions: A case study of the Nile Delta aquifer, Egypt

Study regionClimate change is expected to severely impact Egypt's Nile Delta Aquifer (NDA). Despite its large freshwater reservoir, estimated at 400 Billion Cubic metres (BCM), climate-change-induced drivers (drought and sea-level rise) coupled with increasing groundwater over-abstraction will cause a gradual reduction of the available freshwater volume. This study used the numerical model SEAWAT to study the impact of the main hydrogeological and anthropogenic factors on the response of the submarine groundwater discharge (SGD) (i.e., the net fresh seaward groundwater flux) and seawater intrusion (SWI) in the NDA. Study focusFive scenarios were examined, including (i) a probable Sea-level rise (SLR), (ii) expected reduction in Nile hydrograph and its branches, (iii) freshwater overpumping, (iv) the combination of reduction in Nile hydrograph and overpumping, and (v) the combination of these scenarios in the years 2030, 2050 and 2070. New hydrological insights for the regionThe results show that the increasing saltwater head due to SLR coupled with a reduction in Nile flow and overpumping ultimately results in the landward shifting of the saltwater within the aquifer. In addition, the resulting salinity increase in the aquifer caused a significant increase in the deterioration of a large quantity of freshwater volume with a subsequent reduction of the SGD. Also, the salt mass variation (SMV) in scenario 5 increased to 7.09%, 10.69%, and 12.99%, while the groundwater discharges variation (SGDV) to the sea declined by 21.90%, 42.38%, and 61.95% in the years 2030, 2050 and 2070, respectively. Moreover, the coastal aquifers required the management of the SGD to keep the balance between the freshwater and saltwater interface. This study is useful for the future planning and water resources management in coastal regions for integrated management of SGD, SWI, and aquifer freshwater storage. Also, the applications of smart measurements of SGD and groundwater salinity are required for coastal aquifers management.

Satellite-based estimates of groundwater storage depletion over Egypt

An arid climate accompanied by a freshwater shortage plagued Egypt. It has resorted to groundwater reserves to meet the increasing water demands. Fossil aquifers were lately adopted as the sole water source to provide the irrigation water requirements of the ongoing reclamation activities in barren areas. Yet, the scarcity of measurements regarding the changes in the aquifers’ storage poses a great challenge to such sustainable resource management. In this context, the Gravity Recovery and Climate Experiment (GRACE) mission enables a novel consistent approach to deriving aquifers’ storage changes. In this study, the GRACE monthly solutions during the period 2003–2021 were utilized to estimate alterations in terrestrial water storage (TWS) throughout Egypt. Changes in groundwater storage (GWS) were inferred by subtracting soil water content, derived from the GLDAS-NOAH hydrological model, from the retrieved TWS. The secular trends in TWS and GWS were obtained using the linear least square method, while the non-parametric technique (Mann–Kendall’s tau) was applied to check the trend significance. The derived changes in GWS showed that all aquifers are undergoing a significant loss rate in their storage. The average depletion rate over the Sinai Peninsula was estimated at 0.64 ± 0.03 cm/year, while the depletion rate over the Nile delta aquifer was 0.32 ± 0.03 cm/year. During the investigated period (2003–2021), the extracted groundwater quantity from the Nubian aquifer in the Western Desert is estimated at nearly 7.25 km3. The storage loss from the Moghra aquifer has significantly increased from 32 Mm3/year (2003–2009) to 262 Mm3/year (2015–2021). This reflects the aquifer exposure for extensive water pumping to irrigate newly cultivated lands. The derived findings on the aquifers’ storage losses provide a vital source of information for the decision-makers to be employed for short- and long-term groundwater management.

Impact of Modern Irrigation Methods on Groundwater Storage and Land Subsidence in High-water Stress Regions

Water resources management in high-stress regions is a large-scale problem affecting food and water security. Therefore, modern irrigation systems such as sprinklers, subsurface, and drip irrigations are applied to manage the water shortage in regions of the Nile delta. Because of the increase in population rate and climate change, freshwater supplies are significantly limited and must be efficiently managed. Consequently, Egypt plans to implement MIS in the old land of the Nile delta. The current study aims to investigate and model the recharge from the excess irrigation system that affects groundwater storage and land subsidence unexpectedly. The visual modflow was applied to investigate the groundwater heads and drawdown. At the same time, the analytical solution based on Terzaghi theory, and the surfer software was used to estimate and map the land subsidence.For this reason, we investigated the groundwater drawdown in the high-water shortage of Egypt’s Nile delta. Three scenarios were considered by changing irrigation methods and their Impact on land subsidence in the Nile Delta Aquifer (NDA). Therefore, the results of this study demonstrated that the groundwater drawdown reached 2.60 m, 4.20 m, and 6.50 m, respectively. In contrast, the land subsidence outstretched 26 m, 44 m, and 65 cm for the sprinkle sub-surface. Future design infrastructures such as pipelines, roads, irrigation networks, canals, and water structures should consider land subsidence due to modern irrigation systems (MIS).

Investigating Climate Change Effects on Evapotranspiration and Groundwater Recharge of the Nile Delta Aquifer, Egypt

Climate change (CC) directly affects crops’ growth stages or level of maturity, solar radiation, humidity, temperature, and wind speed, and thus crop evapotranspiration (ETc). Increased crop ETc shifts the fraction of discharge from groundwater aquifers, while long-term shifts in discharge can change the groundwater level and, subsequently, aquifer storage. The long-term effect of CC on the groundwater flow under different values of ETc was assessed for the Nile Delta aquifer (NDA) in Egypt. To quantify such impacts, numerical modeling using MODFLOW was set up to simulate the groundwater flow and differences in groundwater levels in the long term in the years 2030, 2050, and 2070. The model was initially calibrated against the hydraulic conductivity of the aquifer layers of the groundwater levels in the year 2008 from 60 observation wells throughout the study area. Then, it was validated with the current groundwater levels using an independent set of data (23 points), obtaining a very good agreement between the calculated and observed heads. The results showed that the combination of solar radiation, vapor pressure deficit, and humidity (H) are the best variables for predicting ETc in Nile Delta zones (north, middle, and south). ETc among the whole Nile Delta will increase by 11.2, 15.0, and 19.0% for the years 2030, 2050, and 2070, respectively. Zone budget analysis revealed that the increase of ETc will decrease the inflow and the groundwater head difference (GWHD). Recharge of the aquifer will be decreased by 19.74, 27.16, and 36.84% in 2030, 2050, and 2070, respectively. The GWHD will record 0.95 m, 1.05 m, and 1.40 m in 2030, 2050, and 2070, respectively when considering the increase of ETc. This reduction will lead to a slight decline in the storage of the Nile Delta groundwater aquifer. Our findings support the decision of the designers and the policymakers to guarantee a long-term sustainable management plan of the groundwater for the NDA and deltas with similar climate conditions.

Groundwater Quality Modeling and Mitigation from Wastewater Used in Irrigation, a Case Study of the Nile Delta Aquifer in Egypt.

Groundwater is an essential freshwater source because traditional sources of freshwater, such as rainfall and rivers, are unable to provide all residential, industrial, and agricultural demands. Groundwater is replenished by different sources: rivers, canals, drains, and precipitation. This research aims to apply numerical models for a real case study (Bahr El Baqar drain) in the Eastern Nile aquifer to monitor groundwater quality due to the use of wastewater from drains directly in irrigation due to the shortage of freshwater in this area. In addition, the effect of over-pumping from the aquifer is studied to show the extent of contaminants in groundwater. Moreover, a management strategy was achieved through mixing treated wastewater with freshwater to reduce the contamination of groundwater and overcome water shortage. Visual MODFLOW is used to simulate groundwater flow and contaminant transport into the Eastern Nile aquifer (ENDA), Egypt. In this study, three stages including 15 scenarios (five scenarios for each stage) were settled to achieve the study objectives. The first stage was carried out to investigate the impact of using untreated wastewater for irrigation due to the shortage of freshwater in this area. The results of this stage showed that increasing the use of untreated wastewater increased the contamination of the aquifer. The average COD concentrations in the five scenarios reached 23.73, 33.76, 36.49, 45.13, and 53.15 mg/L. The second stage was developed to evaluate the impact of over-pumping and using untreated wastewater for irrigation due population increase and a reduction of freshwater in the Nile Delta. The results revealed that over-pumping has increased the contamination of the aquifer and the average COD concentrations increased to 25.3, 33.34, 40.66, 48.6, and 54.17 mg/L. The third stage was applied to investigate the impact of mixing treated wastewater with freshwater for irrigation to support the freshwater quantity. The results of this stage led to enhanced water quality in the aquifer and the average COD concentrations decreased to 20.26, 23.13, 26.03, 30, and 32.83 mg/L. The results showed that mixing freshwater with treated wastewater has a good influence on water quality, can be safely used in irrigation and reduces the effects on farmers' health and life.

Assessment and adaptation to climate change and sea level rise impacts on Egypt’s northern coasts

Climate change and sea level rise (SLR) represent many challenges for coastal areas such as coastal erosion and saltwater intrusion (SWI). This study aims to highlight the effect of climate change and SLR on Egypt’s northern coasts and present appropriate adaptations. A number of techniques for adapting with climate change and SLR have been presented. Two numerical models have been used for simulation PLAXIS and 2D-FEST. The results showed that SLR will affect a number of cities on Egypt’s northern coasts and the Nile Delta aquifer will be affected by SWI. A number of scenarios have been applied to adapt with climate change and SLR. Precast Diaphragm Wall (PDW) is used to protect Egypt’s northern coasts from SLR. The results showed that PDW is applicable and cost efficient. The cost of building PDW along the north coasts is about 1.0% of the likely losses due to SLR in 2100. However, to control SWI into the Nile Delta aquifer a number of measures have been presented and discussed. The results revealed that using treated wastewater to increase the recharge to the Nile Delta aquifer combined with decreasing the abstraction from the aquifer could help in protecting the aquifer from probable SLR.

Geo-spatial mapping and simulation of the sea level rise influence on groundwater head and upward land subsidence at the Rosetta coastal zone, Nile Delta, Egypt

The coastal zone has been experiencing population growth and incomparable developments that are in discordance with the dynamic nature of the coastal system. The present study focused on the Groundwater Head (GWH) changes and upward land subsidence as a result of Sea Level Rise (SLR). Consequently, the numerical model of SEAWAT is applied to the Nile Delta Aquifer (NDA) at the outlet of the Nile Rosetta branch to simulate the (GWH) for the current situation and the future scenarios of SLR. It was estimated as 5.67, 14.51 and 26.71 cm at the years 2020, 2040 and 2060, respectively. The resulted of GWH are ranged between 0 to 0.40, 0 to 0.45 and 0 to 0.55 cm at the years 2020, 2040 and 2060 respectively. The GWH were then used to predict the future upward land subsidence by applying high least square linear regression analysis. An inverse relationship was found between the GWH and the upward land subsidence with correlation coefficients (r2 = 0.87). Where the hydraulic head increased as a result of sea level rise the rate of upward land subsidence decreased through the years 2020, 2040 and 2060 respectively. The geospatial mapping of the upward land subsidence shows a general increase to the northern part at the Rosetta Promontory, which has the highest thickness and accumulation rates of the Holocene deposits.

An Integrated Approach for Deciphering Hydrogeochemical Processes during Seawater Intrusion in Coastal Aquifers

For managing the freshwater in the worldwide coastal aquifers, it is imperative to understand the hydrogeochemical processes and flow patterns in the mixing freshwater/saltwater zone. The Egyptian Nile Delta aquifer is a typical example. The management of seawater intrusion (SWI) requires detailed investigations of the intrusion wedge and the dynamic processes in the mixing zone. Thus, a multidisciplinary approach was applied based on holistic hydrogeochemical, statistical analysis, and DC resistivity measurements to investigate the lateral and vertical changes in groundwater characteristics undergoing salinization stressor. The results of cross plots and ionic deviations of major ions, hydrochemical facies evolution diagram (HFE-D), and seawater mixing index (SMI) were integrated with the resistivity results to show the status of the SWI where the intrusion phase predominates in ~2/3 of the study are (~70 km radius) and the compositional thresholds of Na, Mg, Cl, and SO4 are 600, 145, 1200, and 600 mg/L, respectively, indicating that the wells with higher concentrations than these thresholds are affected by SWI. Moreover, the results demonstrate the efficiency of combining hydrogeochemical facies from heatmap and resistivity investigations to provide a large-scale characterization of natural and anthropogenic activities controlling aquifer salinization to support decision-makers for the long-term management of coastal groundwater.

Assessment of Changing the Abstraction and Recharge Rates on the Land Subsidence in the Nile Delta, Egypt

The majority of residential, agricultural, and industrial areas are situated on cohesive soil in the Nile Delta, Egypt. Excessive pumping from the Nile Delta aquifer to meet the increasing demands for water could lead to aquifer system compaction and land subsidence. Land subsidence endangers infrastructure such as buildings, bridges, canals, and roads, as well as deteriorating lands and agricultural resources. The objective of this research is to investigate the land subsidence and predict the future behavior of the middle Nile Delta. The study goals are met by using a numerical model (MODFLOW) to simulate groundwater flow and an analytical solution to calculate land subsidence conditions. In this study, three scenarios are considered including; decreasing aquifer recharge, increasing abstraction and combination of the two. The results reveal that decreasing recharge by 94.4%, 88.8%, and 83.2% led to 30-, 60-, and 90-mm land subsidence, respectively, while increasing abstraction by 146%, 193%, and 233% led to land subsidence by 190, 380, and 560 mm, respectively, in the Nile delta. However, the combination of the two scenarios led to 220-, 440-, and 650-mm land subsidence. According to the results the future land subsidence due to over pumping from the Nile Delta should be considered in the future development plans of the country which intend to increase the abstraction from the Nile Delta aquifer. Increasing abstraction could increase the land subsidence that may cause many damages in different properties.

Investigation of Seawater Intrusion in the Nile Delta Aquifer, Egypt

Investigation of Seawater Intrusion in the Nile Delta Aquifer, Egypt

Predictive model for progressive salinization in a coastal aquifer using artificial intelligence and hydrogeochemical techniques: a case study of the Nile Delta aquifer, Egypt.

To monitor groundwater salinization due to seawater intrusion (SWI) in the aquifer of the eastern Nile Delta, Egypt, we developed a predictive regression model based on an innovative approach using SWI indicators and artificial intelligence (AI) methodologies. Hydrogeological and hydrogeochemical data of the groundwater wells in three periods (1996, 2007, and 2018) were used as input data for the AI methods. All the studied indicators were enrolled in feature extraction process where the most significant inputs were determined, including the studied year, the distance from the shoreline, the aquifer type, and the hydraulic head. These inputs were used to build four basic AI models to get the optimal prediction results of the used indicators (the base exchange index (BEX), the groundwater quality index for seawater intrusion (GQISWI), and water quality). The machine learning models utilized in this study are logistic regression, Gaussian process regression, feedforward backpropagation neural networks (FFBPN), and deep learning-based long-short-term memory. The FFBPN model achieved higher evaluation results than other models in terms of root mean square error (RMSE) and R2 values in the testing phase, with R2 values of 0.9667, 0.9316, and 0.9259 for BEX, GQISWI, and water quality, respectively. Accordingly, the FFBPN was used to build a predictive model for electrical conductivity for the years 2020 and 2030. Reasonable results were attained despite the imbalanced nature of the dataset for different times and sample sizes. The results show that the 1000 μS/cm boundary is expected to move inland ~9.5 km (eastern part) to ~10 km (western part) to ~12.4 km (central part) between 2018 and 2030. This encroachment would be hazardous to water resources and agriculture unless action plans are taken.

Impact of Increasing Pumping Discharge on Groundwater Level in the Nile Delta Aquifer, Egypt

The main goal of this research is to develop a 3D groundwater (GW) model using MODFLOW software to assess the potential effect of increasing pumping discharges on GW level in the Nile Delta Aquifer (NDA). In this study, the current state of the irrigation canals and GW recharge are considered in the GW model. The simulated GW level was compared with the observed GW level for model validation. Three vertical cross sections in western central and eastern areas of the ND are selected to check the impacts of GW pumping on variations of GW level. Ten scenarios of increasing the abstraction rates in all areas of the ND are tested. The results confirmed that increasing the pumping discharges has a substantial effect on decreasing the GW level in central and southern areas of the NDA. In addition, the tenth scenario is considered the last case where the drawdown of GW level reached 1.32, 1.59, and 2.41m in the southern boundaries. The findings of the study should be considered when studying the management of GW resources and the impacts of climate change on the ND.