Prediction of runoff from Nagwa watershed using SCS-Curve Number method

A rainfall-runoff model is a mathematical model describing the rainfall-runoff relations of a catchment area, drainage basin or watershed. The soil conservation service curve number method is used for predicting the runoff by using the soil information, rainfall, storm duration, soil texture, type and amount of the vegetation cover and conservation practices. The CN method is one of the most widely used techniques in watershed hydrology. This method has been further simplified by introducing an assumption on initial abstraction which is represented by the potential retention capacity (S) of the watershed. The extensive use of the method is based on convenience and simplicity. For the prediction of runoff soil conservation service curve number method (SCS-CN) is applied to a large set of rainfall-runoff data (24 storm events) obtained from Nagwa watershed. The predicted runoff was compared with the measured runoff and exhibited strong linear relationship R2 = 0.899.