GBHM模型原理及其在中尺度流域的应用

A Distributed Hydrological Model-GBHNM and Its Application in Middle-Scale Catchment

分布式水文模型核心之一是对流域的离散方法.基于地形分析和单位线概念,GBHM利用面积函数和宽度函数概化流域地形特性,将流域划分为一系列内部均一的流带和流条,形成均质坡面流单元,使模型可用一维水份运动方程描述降水产流过程.模型在永定河流域的应用表明,其原理和效率均较为满意.

Watershed dispersion is a key issue of distributed hydrological model. Based on geomorphology analysis, a GBHM （GeomorphologyBased Hydrological Model） was established. The GBHM employs the area function and width function to lump the topography and divides catchments into a series of flow interval-hillslopes. Each interval-hillslope as a basic hydrology unit is a unique hydrological unit, which can be described by 1-D SVAT. The application of the model in the Yongding River basin shows that GBHM is of high efficiency. The Yongding River basin, a 41 692 km^2 semi-arid catchment, is located in North China as a part of Hai River Basin, which is selected as the typical catchment to test the GBHM. The distribu ted physics-based hydrological model is used to simulate the hydrological process, together with hydrological fieldwork, GIS and RS data and distributed parameters. A 30 m× 30 m grid DEM, a 1 ： 250 000 landuse map, a 1 ： 5 000 000 surface soil map, 108 rainfall survey spots with daily data and 14 evaporation survey spots with monthly data are used as model input. 18 discharge survey spots are selected to make calibration and validation. Through applying the model in the Yongding River basin to simulate natural water circle, the features and the applicability was well verified. The using of Basic Hydrology Unit could not only reflect the human activities impacting the rainfallrunoff process with physics-based parameters, but also greatly reduce the computation time. In the case study, the computation time of simulating the whole year water circle by one hour step and 150 m grid is less than three hours in the Yongding Rive basin. It is revealed that the model can be used in larger catchments.