Application And Comparison Of Xinanjiang Model And NAM Model Over The Zishui River Basin

The area controlled by the Xinning hydrological station at the Zishui River was selected as the target region. Based on the 30s-resolution grid-based digital elevation model data, the digital drainage network was generated.Then the subcatchments were carved up and the topological relation table of the drainage network was generated.The Xinanjiang hydrological model and the NAM hydrological model are used to simulate the streamflow processes at the Xinning hydrological station. The years from 1980 to 1985 are selected as the calibration period and the years from 2001 to 2003 are selected as the verification period for daily streamflow simulation. 18 flood events are selected for hourly flood simulation through the xinanjiang and NAM models. The the analysis and comparison on simulated results from The Xinanjiang hydrological model and the NAM hydrological model is performed. Results show that the NAM model could obtain higher accuracy than the Xinanjiang model.The simulated streamflow are analyzed and compared by using information entropy. When the information entropy is computed, the residual square between the simulated results and observed streamflow series is calculated and normalized, and the potential information and the relative information entropy of the simulated streamflow series is derived. Results show that the higher value of relative information entropy could indicate larger similarity of simulated and observed discharge series in the vertical direction, and would not mean higher Nash-Sutcliffe coefficient and lower relative error of runoff volume.The parameters of the NAM hydrological model are researched on affecting the depth of runoff volume, flood peak flux and flood peak appearance time. The result shows that the influence of maximum water content in root zone storage is least on depth of runoff volume; the overland flow runoff coefficient, time constant for interflow and time constant for routing interflow and overland flow have remarkable impacts on flood peaks; the influence of maximum water content in surface storage and maximum water content in root zone storage is less on flood peak flux; the...