Sensitivity Impact Analysis of Different Objective Functions on the Parameters of WRF-Hydro Model
The combination of hydrological and meteorological forecasts can effectively improve the accuracy and forecast period of flood fore-casting.The land-surface hydrological modeling module has become the focus of research by hydrometeorologists.As a new generation of dis-tributed land-surface hydrological model,the WRF-Hydro model has broad application prospects in multi-scale flood forecasting.However,due to the complex parameterization scheme of each physical process and the large amount of calculation of the model,the current parameter sensitivity research of the WRF-Hydro model is insufficient,which also affects the simulation accuracy of the model.This study takes the Tunxi basin in the upper reaches of the Xin´anjiang River in the humid area as the research basin,constructs a set of single-objective and multi-objective functions,and combines Morris method for global sensitivity analysis to explore the parameter sensitivity of the WRF-Hydro model under different objective functions.The result shows that:soil parameters(DKSAT,SMCMAX,BEXP)mainly affect subsurface and surface runoff,and have a significant impact on runoff volume.In particular,DKSAT is the most sensitive and directly affects the movement speed of water in the soil.When increasing,the base flow rate increases significantly while the peak flow rate decreases significantly.;runoff parameters(SLOPE,REFKDT)mainly affect the distribution of surface runoff and baseflow,and have an important effect on the overall shape of the flood hydrograph;the channel routing parameter ManN affects the speed of runoff convergence to channel network and mainly controls the peak time;vegetation parameter MP has a certain influence on annual water volum;overland flow parameter OVROUGHRTFAC and groundwater parameter Zmax are the least sensitive..There are certain differences in the parameter sensitivity order and optimal parame-ter values under different objective functions.The single objective function based on relative bias focuses on the simulation of the total annual runoff and the low flow part,while Nash-Sutcliffe and Kling-Gupta coefficients focus more on the simulation of floods and high flow parts.The multi-objective function comprehensively considers the influence of different objective functions,and the results are better than the sin-gle-objective function to a certain extent.This work can provide a reference for reasonably determining the WRF-Hydro model parameter op-timization strategy.
万方数据
维普
