Compound effects of river routing and local rainfall-runoff for inflow simulation of a large reservoir

Reservoir inflow simulation is challenging due to complex flood wave propagation near reservoirs and limited observed data. This study focuses on Wuqiangxi Reservoir in Hunan Province, China, and evaluates three flood routing schemes. The results indicate that the LIE_land+LIE_river approach showed the best performance, followed by the KW_land+LIE_river approach, and the poorest performance was obtained using the KW_land+KW_river approach. To explore effects of rainfall-runoff processes near the reservoir, the performance of the wflow_sbm model with low calibration effort was compared to the calibrated Xin’anjiang model. The results showed the simulation accuracy of both models reached the second-level standard (the NSE 0.7~0.9) according to the WMR regulations, and the wflow_sbm model demonstrated performance comparable to Xin’anjiang. The results indicate the wflow_sbm model can effectively simulate reservoir inflow floods under various inflow conditions and has significant potential for inflow flood forecasting in ungauged reservoir areas.