Estimation of the surface runoff depth of the Valley Abu Ghar basin using remote sensing and geographic information systems

Abstract

The SCS-CN method is an important model used to estimate the depth of runoff for river basins. This model was developed by the Soil Conservation Service of the United States Department of Agriculture in 1986. This method was adopted to estimate the depth of runoff. The study area is based on the CN values and the amount of recorded rainfall for the station (Hafr Al-Batin) located near the sources of the basin, as the rain data for the above station were dealt with three axes. The first axis included a study of the depth of the surface runoff resulting from a regular rainstorm that was calculated from the average rainfall for days and which It amounted to (11.8 mm / day) and the second axis includes a study of the depth of surface runoff resulting from the highest rain storm for the period (2009-2019), which was recorded on 11/21/2017, reaching (123.9 mm / day), while the third axis includes a study of the depth of runoff Annual surface area based on the average annual total rainfall over the basin. This model depends mainly on the type of land cover, and soil physics (soil tissue). The researcher chose this model for its accuracy and potential in estimating the depth of surface runoff at the level of each value (CN) by the area it represents.