The Construction And Application Of The Distributed Model Based On Excess Storage-excess Infiltration

Flood disasters is a frequentily, widely and destructive natural disaster. Flood forecasting provides decision-making scientifically for flood regulation and control. Hydrological model as an important method of flood forecasting, has been an important branch of the hydrological science. Distributed hydrological model as an important hydrological model, not only can reflect the spatial distribution of the basin underlying surface, but also can be coupled with climate and meteorological data easily, and therefore it has been one of the hotspot issues.This research is founded on National Natural Science Foundation of China (51079131)"The sensibility research on the hydrologic processes to extreme weather events" and The China Meteorological Administration Special Climate Change "The response of the Hydrological processes to extreme precipitation events in henan province", in this paper. A distributed hydrological model is build, which is a loosely coupled distributed hydrological model for the semiarid subhumid features, based on the infiltration excess and saturation excess runoff mechanisms, unit lines and Muskingum method. The watershed of Luhun reservoir is taken as an example to validate the model. Statistics and analysis on every sub-basin outflow and precipitation has been carried on. The region flood level has been divided, some related suggestions and measures to flood risk management in the region are made.(1) The river network is extracted from DEM data using of ArcGIS software. The area is divided into13sub-basins based on characteristics of watershed topography, land use, soil and vegetation distribution.(2) A loosely coupled distributed-hydrological model, which is taken into account the infiltration excess and saturation excess runoff mode, is built base on the DEM. The model was applied in the watershed of Luhun reservoir, and compared with the empirical model simulation. The results show that the simulation accuracy of distributed-hydrological model is higher than that of the empirical model. Therefore, the simulation results of the distributed-hydrological model can provide guidance on the reservoir for flood control, and the empirical model simulation can be used as a reference.(3) Spatial distribution of rainfall, runoff and flood characteristics of the Luhun reservoir are analyzed, and the flood is divided into five levels. The results show that the flood peak, which is more than1609m3/s, has a big risk, but the flood peak, which is less than1609m3/s, has a little risk. The rainfall center in the upstream of the watershed happen frequently, the others is few. The flood risk management is analyzed, and a few proposals and measures are taken, which is taken into account the characteristics of Luhun reservoir basin.