本文提供了基于栅格数字高程模型(DEM)提取流域空间结构, 进行流域自动分割的技术方法。该方法包括地貌形态结构定义、流域结构定义和算法设计3个部分。基于本文设计的算法, 可以从DEM提取完整的汇流网络和分水线网络, 两者组成的多边形集把流域分割成具有拓扑结构的多个子汇流区, 这个子汇流区集作为存贮流域信息的基本地貌单元, 是流域信息进入地学数据库的框架, 也是进行空间分布式机理──过程流域分析模型的基础。并以山西离石黄土丘陵沟壑区的王家沟流域为试验区, 获得了较为满意的结果。

In this paper,the authors present a technique of watershed structure extraction and watershed partition automatically based on gird digitial elevation model(DEM) data . This technique consists of three parts:definition of topographic structure; topographic structure; definition of watershed structure; and algorithm design which is used to extract the characteristics of topography from DEM data. The authors consider that the channel network and the divided network as the two basic frameworks of a watershed. The polygons constructed by the above networks are corresponding to the catchments which make up the watershed. The framework consisting of these catchments, the basic topographic units, and their topologic relationship can be used to store the watershed information and to construct spatial distributed mechanism-course models. The watershed of Wangjiagou in Lishi Gounty of Shanxi Province, located in a gully area in loess plateau, was selected as a pilot study area, and the final results are in accordance with the real condition of the case study area.