Uncertainty Analysis Of Runoff Simulation In Controlling Basin Of Shizhandao Hydrological Station

Hydrological model is an important method and means to study hydrology and plays an important role in understanding hydrologic cycle and solving practical problems of hydrology.With the further development of hydrological theory and science and technology,hydrological models consider more comprehensive factors,but it is still difficult to fully describe the real hydrological process,and the uncertainties in hydrological simulation and predictions are still prominent.Therefore,it is of great practical significance to analyze the input data,model parameters and model structure of the hydrological model and evaluate the influence degree of each uncertainty source on hydrological simulation,which can provide reference information for the improvement of model and simulation accuracy.In this paper,the VIC model is used as a tool to select the control basin of the Shizhandao Hydrological Station on the Zhuozhang River as the research area.After verifying the VIC model in the study area based on the effectiveness of the runoff simulation,we can analyze the influence of different resolution digital elevation model(DEM)and different rainfall interpolation method on runoff simulation,determine the optimal DEM resolution and optimal precipitation interpolation method for VIC model hydrological simulation,and compare it with the runoff simulation results of SCS-CN model from the perspective of the input data.Discuss the influence of model structure on hydrological simulation,summarizes the application characteristics of two kinds of hydrological models and the suitable conditions.Determine the hydrological model most applicable to the study area.The main research results are as follows:(1)With the decrease of DEM resolution(0.5'~5.0'),basin feature accuracy,number of grid cells and monthly runoff simulation accuracy all show different degrees of decline.However,when the resolution exceeds 4.0',basin feature information distortion will be caused by the intensified degree of topographic relief in each grid,and the relative error of runoff simulation will increase sharply.Considering the accuracy of hydrological simulation and the operating efficiency of VIC model,it was concluded that DEM with 1.0'resolution is the best input data.(2)Runoff simulation was performed on the precipitation data after interpolation,and the NSE,R~2,and Re ratios of the inverse distance weighted method and ordinary kriging method were found to be 0.890,0.891,4.659%and 0.856,0.902,-2.707%in rate regular,respectively.During the verification period,it is 0.908,0.912,3.344%and0.912,0.947,-3.780%.The runoff simulation accuracy of the two precipitation interpolation methods is not much different,but the runoff simulation results of the ordinary kriging method are still slightly better than the inverse distance weighting method.Precipitation is also closer to the actual rainfall.(3)The runoff simulation effect of SCS-CN model is very poor,and the NSE,R~2and Re in the rate period and verification period are 0.686,0.842,-29.394%and 0.632,0.955 and-37.351%,respectively.In comparison,the NSE,R~2 and Re in the rate period and verification period are 0.890,0.891,4.659%and 0.856,0.902,-2.707%,respectively.The runoff simulation accuracy is higher,which is more suitable for this study area.