Abstract
The current study would use geophysical investigations and geo-informatics to assess the groundwater aquifer at Wadi Dawqah-Al Baha. The morphometric analysis of the drainage basins gives a complete picture of the best catchment areas for surface water, which consider the main feeder for the groundwater aquifer. For the area drainage basin, a digital elevation model, slope, aspect, and drainage pattern maps were developed. The drainage pattern of the study area appears to be dendritic, with five major tributaries converging at the study area. Various metrics for calculating drainage basin morphometry, such as stream number, flow order, flow length ratio, bifurcation ratio, basin length, basin area, relief ratio, streaming density, flow rate, shape factor, and circulation ratio have been studied using conventional mathematical formulas. Eighteen vertical electrical soundings (VES) were conducted using a Shlumberger array with a maximum AB/2 of 200 m. While the time domain electromagnetic (TDEM) survey was conducted at eight different locations along the Wadi using a coincident loop configuration in which signals were transmitted and received using the same loop. The effects of the interpreted VES and TDEM soundings are used to create a variety of cross-sections and maps of resistivity, thickness, and depth of the aquifer layer. These maps display a smooth distribution of aquifer resistivity values ranging from 30 to 190 omega m. The average thickness of the water saturated Wadi deposits (aquifer) layer ranges from 16 to 50 m. The aquifer depth shows moderate values ranging from 14 to 26 m. On the other hand, the presence of four geoelectric layers is detected in the built resistivity cross-sections along some profiles. The resistivity values and average thickness of each layer were identified and their corresponding interpreted geological cross-sections were constructed.