基于DEM的数字降水径流模型在——黄河小花间的应用

Digital Rainfall-Runoff Model Based on DEM:The Application to Xiaolangdi-Huayuankou Section of the Yellow River Basin

DEM是目前用于流域地形分析的主要数据,在流域地形分析及水系构建等方面形成了比较成熟的算法,基于DEM的水文模拟技术的应用给传统的水文模拟方法带来了根本性的变化。基于栅格型DEM,应用最新引进的WMS专业水文处理软件,结合Arc/info、Arcview地理信息系统工具,以黄河小花间(小浪底-花园口区间) 卢氏以上流域作为研究区,进行了数字降水径流模型的应用研究。

DEM is the main data source which is used in watershed analysis. There are many mature algorithms in watershed analysis and they can be used to delineate the drainage networks. Applications of the methods based on DEM make significant innovation in hydrological simulations. Topographic parameters which are used in hydrological models can be automatically calculated from DEM. The article introduces the main process to determine watershed geometry, drainage network and other map-type information for hydrological models. Lushi basin, located in the upper Luohe river which is a tributary of the middle Yellow River, was selected as the study region with an area of 4,623 km2. WMS6.1, a GIS hydrological tool, which is introduced to China recently, was used to develop the digital rainfall-runoff model, and other GIS tools such as ARC/Info, Arcview were also used to deal with the data. The drainage network was derived from 1:250,000 DEM, and the region was divided into seven sub-basins. HEC-1 model, a part of hydrological models in WMS, was selected to simulate the rainfall-runoff process. Curve Numbers (CNs) and other parameters were automatically calculated to input to models directly. Five historical flood events were simulated. The results demonstrate that the method was more efficient than trade method. Although it is very easy and quick to input and output data for the models, it does not mean that the hydrological model itself has high quality, so it is necessary to develop hydrological models which can be adapted to the region.