الخصائص الجيومورفولوجية لحوض وادي العقيق بمنطقة المدينة المنورة

Abstract EN

The absence of hydrometric stations to gauge the surface runoff of the Wadis in Saudi Arabia is the problem preventing the exact identification of hydrological characteristics of surface drainage systems in arid basins.

Therefore, this research seeks to identify the relief and morphometric characteristics that control the hydrological characteristics of the wadi A1 Aqiq floods using Digital Elevation Model data with resolution of 30 m, and the outputs of Spatial Analysis in ArcGIS ArcHydro extension , the (WMS) Watershed Modeling System and available rainfall data in the stations of A1 Faqir , Umm A1 Biraq, A1 Musaijid and A1 Madinah A1 Munawarah gauged over from 1974 to 2004 (31 years).

The watershed of Wadi A1 Aqiq has been selected because of its hydrological importance with a drainage area of 5130.8 km2 and its drainage area contained A1 Madinah A1 Munawarah urban area and the Holy Mosque.

In the absence of the hydrometric stations in the drainage area of Wadi A1 Aqiq basin this research is based on the SCS dimensionless unit hydrograph to compute the discharge peak of the sub-basins of Wadis Rym , A1 Yatmah, oAl Ash and Shuaib Slim .

In order to achieve the objectives of this study the digital elevation model outputs with a resolution of 30 m are used to calculate the morphometric and relief variables needed in the experimental equations of the hydrological model applied in this study.