Use of Numerical Groundwater Modeling to Assess the Feasibility of Aquifer Storage and Recovery (ASR) in the Wadi Watir Delta, Sinai, Egypt

Abstract

The lack of water resources in Egypt's Sinai Peninsula is a major constraint for further socioeconomic development, and flash floods in this region can damage roads and infrastructure. The Wadi Watir basin is the main water source for the groundwater aquifer, which supplies fresh water to Nuweiba city, where demands for groundwater are increasing. The objective of this research was to assess the hydrogeological suitability of installing Aquifer Storage and Recovery (ASR) systems in the Wadi Watir delta by using numerical groundwater models. The developed models were used to evaluate the effects of hydrogeological and operational parameters on the recovery efficiency of ASR systems at five potential locations in the study area. As the estimation of recovery efficiency depends on the salinity of recovered water, the recovered water salinity limit was assumed as 150% of the injected water salinity, where 150% refers to the point at which recovery has ended because the concentration of recovered water reached 150% of that of injected water. The most important output from the model runs was that the recovery efficiency of these ASR systems ranged from 25% to 54% with a longitudinal dispersivity of 10 m, volume of injected water of 12,000 m 3 , and storage period of 180 days. The main conclusions are as follows. 1) Using coupled numerical groundwater flow and solute transport models is an effective tool for predicting the effects of mixing between injected water and ambient groundwater in ASR systems.2) The groundwater aquifer in the study area is not suitable as strategic area for ASR systems because the thickness of the water storage layer is relatively small and the distance to the sea is very close; consequently, it is recommended that artificial recharge systems be developed with existing technology to replenish the groundwater aquifer in the Wadi Watir delta.

Delineating MAR Sites Using GIS-MCDA for Nuweiba Alluvial Fan Aquifer, Sinai, Egypt

“…The suitability map has been compared with the previous study conducted by Sallam [6], who studied the feasibility of installing ASR in the study area. The comparison shows that the highly potential MAR site locations on the suitability map are near to the suggested ASR site locations "A1", "A2" and "A3" proposed by Sallam [6] (Figure 6).…”

“…The suitability map has been compared with the previous study conducted by Sallam [6], who studied the feasibility of installing ASR in the study area. The comparison shows that the highly potential MAR site locations on the suitability map are near to the suggested ASR site locations "A1", "A2" and "A3" proposed by Sallam [6] (Figure 6). Sallam [6] concluded that the "A1", "A2" and "A3" site locations are characterized by a high recovery efficiency at low dispersivity compared to the latter, especially "A1", using the numerical modeling method.…”

“…The hydraulic conductivity values were estimated by Khalil [14] as 54 m/day by interpreting geo-electrical data, and 1 to 12 m/day by Himida [15] via interpolating the pumping test analysis results. These results were calibrated using groundwater flow models by Eissa et al [1] and Salam [6] as 4 m/day for the three upper layers, 11 m/day for the fourth layer, and as 0.001 for the lowermost layer. Additionally, Himida [15] calculated the transmissivity parameter such that the value ranged from around 65 to 500 m 2 /day.…”

“…Himida [15] mapped the vertical permeability, groundwater table, transmissivity, and storativity. In addition, hydraulic conductivity data were collected from Eissa et al [13] and Sallam [6] by calibrating the groundwater flow model. The groundwater hydraulic gradient was processed by ArcGIS 10.7.1 (developed by ESRI (Environmental Systems Research Institute) located in Redlands, California, USA) by using the groundwater table as input data.…”

“…Eissa et al [1] modeled the groundwater system using Modular Finite Difference Groundwater Flow (MODFLOW), Net Geochemical Reactions Along a Flow Path (NETPATH), and Simulation of Three-Dimensional Variable-Density Groundwater Flow and Transport (SEAWAT) models to understand the recharge sources to the aquifer. Sallam [6] modeled the suitability of Aquifer Storage Recovery (ASR) to the system using the linkage between MODFLOW, MODPATH, and Three-Dimensional Multi-Species Solute Transport (MT3DMS) to evaluate the recovery efficiency when injecting freshwater into the aquifer. Elewa and Qaddah [7] mapped the groundwater potential for Sinai using RS and GIS in order to assess the groundwater resources.…”