Effect Of Temporal Scale On Flood Prediction Model In Semi-arid And Semi-Humid Drainage Basin

In the process of the watershed hydrology model developing, moist area makes more works in the south region, the calculating method of the hydrology model in this area is also relatively mature. But the works in semiarid and semi-humid area makes less than the south area. Either in the domestic or on abroad, there still have some problems about the hydrology model when it is applied in the semiarid and semi-humid area. Therefore, the studying on the hydrology simulation of semiarid and semi-humid area is very important.For our present purposes, the study toward hydrology temporal scale mostly use year, month, day for removed scale, while the research which based on flood prediction model use hour for temporal scale is extraordinary paucity. the research which based on flood prediction model use hour for temporal scale possess important value for advance precision of the flood prediction model, analyses flood forecasting scheme in different region and in different climate style , as well as research a series of problem of rainfall elapsed time, in addition developing this study on this line in favor of penetrate into known how about to found hydrologic model which be on speaking terms with different time scale, in favor of analyses the interconversion law of the parameter of identity hydrologic model at different time scale.This paper introduce the flood prediction model in semi-humid and semiarid drainage basin( SAH model for short), and use wenyu river base for case, further studies on SAH model at hydrology scale aspect. Seeing differ scale simulative demand, scaling the rainfall data, introduce fractal geometry theory, and applicate similarity theory of fractal geometry theory, upscaling and downscaling the rainfall data, be about to upscaling the foundation 1 hour rainfall data become to 2 hour, 3hour interval' rainfall data, and downscaling it become 0.5 hour interval 'rainfall data.Combine static parameter means and dynamic parameter means, study the infection of time scale to flow simulative. Simulation results proclaim runoff simulation if more sensitivity for the variation of rainfall temporal scale, when adopt rainfall data with different time scale to model, the hydrology parameter is not incapable of transplantation, must reset parameter.Variation of rainfall time has important infection to across flow simulation results, but view through static parameter model results of rating, simulation results of 1h, 2h and 3h are reasonable. So it's not right that higher distinguish (smaller scale)better simulative outcome. Modeling simulation scale should have a threshold, and the best model scale is there. Questing the threshold and the best model scale can economize excessive computation time and escape the error that brought in high resolution observation.