Performance Assessment of Modest Event-Based Rainfall-Runoff Model

Abstract

A very simple and widely used SCS-CN method is a time-independent method that is used to calculate accumulated runoff corresponding to a single rainfall event. The method requires only two parameters initial abstraction coefficient (λ) and the potential maximum retention (S) expressed in terms of curve number (CN). The CN value incorporates many factors in its own and can be adopted for different climatic conditions. In the present study, a modest and easy to use non-linear event-based rainfall-runoff model is used which consist a single parameter α without taking into consideration of initial abstraction coefficient (λ) and curve number (CN). The quantitative model performance was assessed and compared based on RMSE, NSE and PBIAS (per cent bias) value. Based on the statistical criterion, the proposed model without CN concept reveals more statistically significant results (low RMSE, high NSE and statistically significant PBIAS values) and depicted improved performance than the conventional CN model.