Construction Of Distributed Hydrological Model In The Middle Route Of South-to-North Water Diversion

Watershed hydrological process is affected by climate, underlying surface and other factors, presenting large differences. The traditional lumped hydrological model does not consider the spatial heterogeneity, while distributed hydrological model make up for the deficiency, can reflect the hydrology and water resources change in space, do the calculation on the condition of underlying surface change, have more simulate function, that is to be able to transfer single water quantity change simulation to a wide range of water resources and ecological environment problems simulation.The research based on the eleven-five country important technology plan—water resources operation key techonology research, runoff process in the whole area of the Middle Route Project of South-to-North Water Diversion was simulated by distributed hydrological model—WEP-L model. The parameters were calibrated and the model was verified by observed hydrological data that prove the model is available in the research area. During the process of hydrological model development in the middle route of South-to-North water diversion, a new general watershed delineation method was proposed, which can automatic refining to narrow and long reaches and reaches without junction and refining to sub-catchments considering the positions of reservoirs and hydrological stations. The method used in the research region, and the result proved it is better than before.The new module of parameter homogeneous region was developed in the paper. The parameter homogeneous region not only the important mean to recognize hydrological regular pattern and provide foundation for water resource rational development, but also the foundation to solve hydrologic station plan and regulation, therefore improve the efficiency rate of parameter sensitivity analysis and calibration.On the basis of distributed hydrological model in the middle route of South-to-North water diversion, scenario analysis of climate change on runoff volume in the upper reaches of the Han River was done. In recent forty-five years, in the region temperature was presented as a fluctuant upper trend, meanwhile, precipitation and runoff were showed as a downward trend. At different climate change scenarios, runoff changed significantly in forty-five years, but change ratio remain in the same level and effect on runoff by precipitation is larger than temperature.