APPLICATION OF THE GIUH APPROACH FOR THE COASTAL PLAIN OF SYRIAN ARAB REPUBLIC

Abstract

The mam objective of this study is to predict the discharge hydrographs for the wadis of AI Kebir AI Shemali River Basin at the western part of the Syrian Arab Republic. The Geomorphologic Instantaneous Unit Hydrographic (GIUH) approach has been utilized for this purpose. Two different presentations of the infiltration losses in watershed channels were tried. The first presentation is the 0 - index method, and the second infiltration presentation is Philip's expression. The input parameters of Philip's infiltration expression are estimated from the available soil and geologic data. The 0 - index was estimated from the available rainfall -runoff data of the basin. Based on the two infiltration expressions and the GIUH, two discharge hydrograph simulation models were derived via the convolution transformation. The models were applied for two gauged watersheds in AI Kebir AI Shemali basin; namely wadi Kferyeh (64.6 km 2 ), and wadi AI Heffeh (94.223 • km 2 ). The Geomorphologic parameters were obtained from topographic maps with a scale of 1:50,000. A comparison between the simulated and the available observed hydrographs was made. The models result were found in a good agreement with the observed hydrographs. However the 0-index, because of its simplicity, was found preferable to the Philip's infiltration expression.