Groundwater Potentiality of Wadi Fatimah, Western Saudi Arabia: Geophysical and Remote Sensing Integrated Approach

Abstract

To detect groundwater-bearing potential zones in Wadi Fatimah, western Saudi Arabia, geophysical data from three profiles of two-dimensional electrical resistivity tomography (ERT) and remote sensing data were gathered, integrated, and evaluated. The DEM and slope maps indicate that Wadi Fatimah has a high potential to store great amounts of groundwater. The maximum elevations range from 0 to 933 m, with an average elevation of 466 m AMSL. The amount of surface water that infiltrates into the ground is affected by the slope. Rainwater can be collected in low-sloped areas and percolate into the subsurface, replenishing groundwater. In the study area, the slope ranged from 0° to 38°. The slopes of Wadi Fatimah ranged from 0° to 9.1°, with highlands having slopes ranging from 9.1° to 38°. Wadi Fatimah has a high stream density. Furthermore, because it is unconfined, the groundwater-bearing zone reaches the ground surface and recharges continuously during the rainy season. The drainage density is 0.433 km/km2, which is considered normal for coarse drainage. Lithology, infiltration capacity, and topographic relief all have an impact on drainage texture. Because of the basement rocks’ low slope, a coarse drainage texture of 0.059 was calculated, indicating additional groundwater recharge from precipitation. Moreover, based on the 2D inversion results of the ERT data, Wadi Fatimah’s unconfined aquifer has a high potential for groundwater. This aquifer is distinguished by a zone of low resistivity (less than 100 Ω.m) and a depth of up to 50 m below the ground surface. This aquifer is underlain by the weathered/fractured and/or fresh basement rocks. Wadi Fatimah basin is recharged by rainfall creating a promising or strategic area for groundwater supply for future planning and urbanization projects in surrounding areas.