Application of HEC-HMS Parameter Regionalization in Small Watershed of Hilly Area

To explore the applicability of HEC-HMS and its parameter regionalization in small ungauged watersheds in hilly areas, this paper takes hydrological divisions III and IV of Henan Province as the research area. The HEC-HMS model is applied to three typical small watersheds in Luanchuan, Gaocheng and Xiahecun. On the basis of verifying the validity of the model, the regression relationships between model parameters and underlying surface characteristics are established and verified in the Zhongtang small watershed. The results show that the qualified rates of runoff depth, flood peak flow, peak occurrence time and NSE in flood simulation are higher than 75%, and the accuracy reaches the grade B level regardless of the HEC-HMS model test or the parameter regionalization method verification. In summary, the HEC-HMS model can be applied to simulate the rainfall-runoff process of small watersheds in hilly areas, and the parameter regionalization method can effectively deduce the model parameters of HEC-HMS for small ungauged watersheds in hilly areas.