Estimating the Volume of Surface Runoff Using the SCS-CN Model for Wadi Ain al-Marrat Basin in Najaf Governorate

Abstract

The research aims to estimate the volume of surface runoff and its spatial distribution, as the research problem focuses on the climatic fluctuation of rainfall, as the world is witnessing climatic changes represented by rising temperatures and lack of rain, which has led to the expansion of large areas of barren areas. The Ain al-Marrat basin is administratively located within the Najaf Governorate between two longitude lines (20° 50° 43° - 30° 6° 44°) to the east and two latitudes (20° 51° 31° - 3° 1° 32°) to the north. It is considered one of the seasonal basins with an area of ​​(160.5 km2), where the (SCS-CN) method was relied upon, as it is one of the important methods for arriving at accurate estimates. To determine the volume of surface runoff, to determine the hydrological type of soil, and to determine the type of vegetation cover. This method was applied to Wadi Ain al-Marrat using geographic information system software (ArcGis10.4). And remote sensing techniques, which require several stages of equations, procedures, and the approved mathematical formula to measure surface runoff in the study area.