Abstract
The current study presents special information about the conditions of surface water flow represented by the depth and volume of runoff of the basin of Wadi Al-Sahliah located in Iraqi western plateau, which has an area of 6019.3. Many mathematical models have been formulated by specialists to describe the hydrological work of the water basins and the affecting factors where their results have received wide acceptance and an effective tool in decision-making with respect to estimating the volume and depth of surface runoff and preventing flood risks.
Therefore, one of the important methods used in calculating surface runoff in hydrological studies is the curve method. This model is developed by the US Soil Conservation Service in 1986. This method is used in calculating the volume of surface runoff for Wadi Al-Sahliah through (CN) values and rain quantity recorded in Rutba station. The highest single rain fall recorded during the period from (2003-2013) on (12/29/2013) is adopted as it reached (40 mm), where the depth of surface runoff in the Wadi Al-Sahliah basin for the same rainfall reaches (17.74 mm), and the volume of surface runoff reaches (106.782.380 billion m2). In order to obtain accurate results according to the model adopted, the data is analyzed to achieving integration between a set of modern software represented by remote sensing data and geographic information systems (GIS) outputs which clearly affect the analysis of the hydrological characteristics of the basin and then reveal the relationship between the type of land cover and the types of hydrological soils.