Runoff Estimation by Using the (SCS-CN) Method with GIS and RS for Wadi Shuieb Watershed
Noah M. Al-Sababhah and Alaa A. Al-omari, Department of Geography, Yarmouk University, Irbid, Jordan.
Abstract
The goal of this study is to estimate surface runoff using (SCS-CN) and Geographic Information System and remote sensing (GIS &RS) in Wadi Shuieb Basin which is located within the dry region in central Jordan. The maps of the hydrological soils and land use / land cover were used within the GIS environment toolbox to produce table and map of the curve number (CN). The model of the curve number was then used to estimate the runoff which corresponds to the rain storms within the watershed.
Due to the inconsistence records of runoff within the study area, the SCS-CN model was found to be an effective method for estimating the runoff generation. The results show that the SCS-CN method provides high-precision results in estimating surface runoff which particularly based on rain storms. The corresponding values were (57.7), (76.5) and (88.4) under dry, normal and wet conditions respectively. This in turns influences the surface storage (S) and the initial loss (Ia). The results furthermore, illustrate that the highest rate of surface runoff (64940 m3) was in Salt meteorological station, whereas (Ira) meteorological station has the lowest rate of surface runoff (14580 m3).
Key Words: Surface Runoff, Curve Number, Wadi Shuieb, Hydrologic, Soil Conservation Service Model.