Applicability Analysis of Different Runoff Schemes of the Gulang River Basin in Arid Region of Gansu Province, China

[Background] Mountain torrent disasters are one of the deadliest weather-related natural in world, often causing extremely serious economic and property losses casualties; recent years, due to heavy rainfall complex geological geomorphological conditions, mountain have occurred frequently Gansu Province. An effective rainfall-runoff model is key prevent them. There still many problems about how establish suitable hydrological models arid basin China. [ Methods ] Therefore, Gulang River Basin Province was selected as research area construct HEC-HMS model; through screening different runoff methods, schemes were established explore optimal algorithm for basin; there mainly SCS-CN method, initial constant Green Ampt method exponential loss generation; SCS unit hydrograph Clark methods slope transform, kinematic wave lag algorithms channel routing, totally 16 schemes. Three floods analyze simulation effect Basin. Results ]1) If Nash-Sutcliffe efficiency coefficient evaluation index, best results 1 20180826 flood, 2 20190626 flood 3 20190911 flood. percentage peak error 9 6 13 4 flood.If depth indicator, 8 7 2)The mean value obtained by generation, transform routing 0.8, 0.65 0.65, respectively; absolute errors 9.29%, 9.71% 8.47%, 6.07%, 7.17% 7.74%, time difference 1.21 hour 1.5 hour, respectively.[ Conclusion ]The most scheme combination routing. The can provide a certain reference prevention region