Rainfall-runoff estimation by SCS-CN method: A case study

Abstract

When the precipitation rate is greater than infiltration capacity, it results in the surface runoff. The aim of this study was to estimate the runoff depth in a catchment area using Soil Conservation Service Curve Number (SCS-CN) method. This method has been extensively applied in hydrological studies due to its simplicity, computational efficiency, and reasonable accuracy in predicting runoff volumes. The total area of study is about 10 km2. The SCS-CN method involves the estimation of curve numbers, which represent the soil-water infiltration and runoff potential for different land use and soil conditions. Various factors influencing curve number determination, such as antecedent moisture conditions, land use, soil type, and hydrological region. Estimation of direct rainfall-runoff is always efficient but is not possible for most of the location in desired time. The effect of land use/land cover changes on runoff from watersheds. Rainfall and runoff are important component contributing significantly to the hydrological cycle, design of hydrological structures and morphology of the drainage system.