Delineation of water potentiality areas at Wadi El-Arish, Sinai, Egypt, using hydrological and geophysical techniques

Abstract

The position of Sinai Peninsula as an area of transit from Africa to Asia and vice-versa, is so strongly reflected on its importance on the projects of sustainable development in Egypt. Wadi El-Arish basin, largest drainage system in Sinai Peninsula, exhibits variable morphologic features due to the impact of the local lithologic, tectonic, topographic features and arid climatic conditions with intermittent flash floods. The present work attempts to determine the flood parameters: peak discharge, runoff volume and time to peak discharge. Due to lack of runoff measurement, Soil Conservation Service (SCS) unit hydrograph method is used to compute the runoff hydrographs. Rainfall data of all effective rainfall stations for 100 years design storm is incorporated in the Hec-1 hydrologic module. Also, the land use and soil type map are used to estimate the water losses and accordingly the excess rainfall which causes runoff. For that, Wadi El-Arish has been subdivided into nine sub-basins; ranging in area from 509 to 6111 km2. Drainage network, geometry and relief aspects were determined for the different sub-basins. The runoff volume ranges from 4.19 to 59.30 million m3. Additionally, geophysical technique in the form of gravity data with geological and hydrological techniques have been employed to delineate groundwater potential zones in Wadi El-Arish catchment area using GIS-based techniques. The resulting GIS model shows that the most favorable areas for groundwater potentiality are located at the southern part of Wadi El-Arish at Wadi Abu Tareifiya sub-basin and to the south of Wadi El-Azariq sub-basin.