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The current study focuses mainly on understanding the hydrogeological framework of southeast Hiw, Qena, Egypt, as one of the promising regions for land reclamation and future development. This includes defining the groundwater aquifers and delineating their lateral extents, depths, and thicknesses, as well as getting some information on the groundwater quality in the area. These objectives have been accomplished by the integrated interpretation of remote sensing imagery and vertical electrical sounding (VES) data. The digital elevation model (DEM) of the Shuttle Radar Topography Mission (SRTM) was processed to calculate the surface gradient and delineate the structural lineaments and drainage channels. Moreover, VES data were measured at 32 locations using Schlumberger configuration. The result of the VES survey has been presented in the form of 2D cross-sections, 3D fence diagram, and hydrogeophysical contour maps. They reveal that the Quaternary sand is the main groundwater aquifer in the region. It has a depth of 30 to 58 m, a thickness of 30 to 68 m, and a resistivity range of 48 to 93 Ω.m. Furthermore, an empirical resistivity–salinity relationship was developed. Accordingly, total dissolved solids (TDS) values vary from 600 to 1500 ppm. This study improves the understanding of the subsurface geology of the region and serves as a guide for further studies regarding digging new wells and groundwater management in such an arid environment. [ABSTRACT FROM AUTHOR]

Abstract Due to the overpopulation in the main cities and shortage of water in Egypt, finding new possible reclamation areas becomes an urgent necessity. The area northwest of El Sadat city can be considered one of the most promising new reclamation areas. This study focuses on detecting the groundwater aquifers, delineating the best localities to drill groundwater boreholes, and evaluation of the groundwater quality. To achieve these goals, an integrated study of vertical electric sounding (VES), time domain electromagnetic (TEM) sounding, and hydrochemical analyses has been executed. The results show that the Pliocene aquifer is the main groundwater aquifer in the survey area where it is divided into two sub-aquifers. The first aquifer is encountered at depth ranging from 30 m to 70 m, where it's thickness range is 20–60 m and its resistivity is varying from 28 to 70 Ωm. The second aquifer is recorded at depth range from 95 m to 135 m with resistivity values of 33–57 Ωm. Moreover, the suitability of 57 groundwater boreholes for drinking and irrigation purposes was assessed as they were compared with the known standard guidelines values. Piper's tri-linear diagram shows the dominance of Alkaline earth (Ca2++Mg2+) and strong acids (SO 4 2− + Cl−) in most of the water samples. According to the concentrations of major ions, the water types in the area are: Ca HCO 3 (22.8%), Ca SO 4 (17.5%), Na SO 4 (15.8%), Na Cl (14.0%), Ca Cl (14.0%), Na HCO 3 (10.5%), Mg HCO 3 (3.5%), and Mg SO 4 (1.8%). The electric conductivity (EC) and the total dissolved solids (TDS) values suggest fresh to brackish water. The groundwater is classified according to its total hardness (TH) based on the calcium carbonate concentration into moderately hard, hard and very hard water. Water quality indices such sodium adsorption ratio (SAR), sodium content (SC), permeability index (PI), and residual sodium carbonate (RSC) were considered to evaluate the groundwater quality for agricultural activities. These parameters suggest a safe and suitable groundwater for agricultural activities. Before exploitation further studies are however essential in order to establish a sustainable level of abstraction from the aquifer, as well as assessing the vulnerability to protect it from pollution. Highlights • The use of VES and TEM techniques to detect Pliocene aquifer and its properties. • Evaluation of the groundwater quality using hydrochemical analysis. • Results suggest a safe and suitable groundwater for agricultural activities. • The southwestern sector is the most suitable place for drilling new boreholes. • A linear equation was constructed to calculate TDS value directly in the field. [ABSTRACT FROM AUTHOR]