An artificial neural network and SCS-CN-based model for runoff estimation: a case study of the Peddavagu watershed

The accurate prediction of runoff from rainfall events is crucial for effective water resource management, especially in regions with diverse climatic patterns like India. This study proposes a novel approach by integrating the soil conservation service (SCS)-curve number (CN) method with artificial neural networks (ANNs) to model rainfall-runoff relationships. In this research, an SCS-CN method is utilized to estimate initial runoff volumes, accounting for local soil and land-cover characteristics. Subsequently, an ANN-based model is developed to capture the complex nonlinear relationships between rainfall inputs and runoff outputs. Taking the rainfall of the watershed as the inputs, an ANN model was developed in MATLAB for runoff simulation at the main outlet of the Peddavagu watershed. A feed-forward back-propagation method is employed in the ANN model. The architecture with a 1-10-1 configuration based on tan-sig transfer function performed well in terms of MSE 0.019 and R-2 values, which were 0.96 and 0.98 for the training and testing phases, respectively. The model efficiency was satisfactory with the coefficient of correlation (R), 0.96 for training, 0.98 for validation, and 0.98 for testing period. The overall value of R (0.96) indicates the utility of this ANN-SCS-based coupled model for rainfall-runoff simulation.