DISCUSSION ON CLEAN WATER FLOW CHARACTERISTICS OF DEBRIS FLOW UNDER DIFFERENT RAINFALL TYPES BASED ON HEC-HMS

This study builds the basin model of Zengda gully using SCS method and Kinematic wave method in HEC-HMS.Then it calculates the clear water flow of basin model under 12 different types of rainfall and discusses the flow characteristics under different rainfall types. The results show that the peak flow rate is linear positive correlation with the arrival time of the peak of rainfall and the concentration degree of rainfall(the power number of rainfall model).The delay time of peak flow is twice correlation with the arrival time of the peak of rainfall and the concentration degree of rainfall. The two elements multiple equation fitting for the two groups of variables and the fitting effect is good. By comparing the calculated results of HEC-HMS with the results of the inference formula method, the differences between the two results and their advantages of each method are evaluated.