Simulation on flood processes based on three rainfall runoff schemes: A case study of Sunshui River Basin in Southwest China

Accurate simulation of floodpeak and its hydrograph is crucial for flood control and disaster reduction analysis. The selection of rainfall loss and runoff generation model is often critical for flood process simulation. To evaluate the applicability of different rainfall loss and runoff generation models in the Sunshui River Basin in Southwest China, this study constructed three rainfall-runoff modeling schemes (scheme 1: SCS Curve Number method+Snyder Unit Hydrograph method, scheme 2: Initial Constant Rate method+Clark Unit Hydrograph method, scheme 3: Green-Ampt method+SCS Unit Hydrograph method). The HEC-HMS model was used to simulate 15 flood events from 2007 to 2018. The results showed that Schemes 1 and 2 demonstrated satisfactory performance in simulating the flood hydrographs in the study area, with Scheme 1 performing better for single-peak flood events and Scheme 2 performing better for double-peak flood events. In comparison, Scheme 3 exhibited inadequate simulation performance. The findings of this study can provide reference for flood simulation and prediction in similar areas.