Wadi Bany Omair is located within Makkah quadrangle, between Longitudes 39º 54' 39.4" E & 40º 03' 41" E, and Latitudes 21º 39' 31" N & 21º 41' 01.7" N. This wadi acquires its importance from its location near the Holy Makkah town by about 20 km. It is one of the most important tributaries of wadi Fatima, which contributes in feeding the western parts of Saudi Arabia with groundwater. The study area lies within the western central section of the Arabian Shield which, consists of plutonic igneous rocks of Precambrian age, volcanic rocks from Miocene and Paleocene age as well as Quaternary sediments.
The main objective of this study is to asses the groundwater potentiality through locating the most suitable sites for drilling productive wells in the wadi. The ground magnetic and DC resistivity methods were used to achieve this aim. The wadi was covered by about 41 ground magnetic profiles perpendicular wadi direction and about 106 vertical electrical soundings (VES) with Schlumberger configuration in a total distance about 20 km along the wadi. The total magnetic intensity data were subjected to regional-residual separation at two depths, determined from power spectrum curve for each profile. The VES data analysis was performed using two geoelectric software; ATO program of Zohdy (1989) to construct the multi-layer models and IPI2Win program (2001) for layering models.
The combined geophysical study revealed that the maximum depth to the basement is 68 m, and the minimum is 8m, with an average value of 35m. Also, the average thickness of the water-saturated zone reaches 14 m and the depth to the water table is 30m. The study succeeded to postulate 25 promising sites, which represent the most appropriate locations for exploratory wells in the region.