Research of Sensitivity Analysis Module of SWAT Model in Middle-scale Watershed——A Case Study of Hongmenchuan Watershed in Miyun County

The soil and water assessment tool(SWAT) is a physically-based continuous event hydrologic model.This paper mainly introduces the sensitivity analysis model of the module AVSWAT 2005 principle,application and verified in Hongmenchuan watershed.Based on the sensitivity analysis,the main parameters affecting the simulated values in this watershed were determined,the CN2、the SOL_AWC and the SOL_K were the significant and sensitive parameters.Adjusting the parameters based on the analyzed results,using 1991 to 2006 continuous simulations on monthly runoff,satisfied simulation results were obtained with the relative error was under 15%,Nash-suttcliffes coefficient(Ens) more than 0.7,and correlation coefficients R2 exceeding 0.8,SWAT model of Yunzhou reservoir basin simulation result is good.Therefore,the application of sensitivity analysis module of SWAT model in soil-gravel area in middle-scale watershed of smaller area has improved the accuracy of simulation dramatically.