从规则格网DEM自动提取汇水区域及其子区域的方法

从DEM自动提取的汇水区域及其子区域信息对进一步的水文分析有着重要的辅助作用.在经过洼地处理的DEM及得到水流方向矩阵的基础上,本文提出并实现了一种汇水区域及其子区域的提取算法.该算法首先提取整个DEM区域内每条河流的汇水区域,然后按照不同的要求划分子区域.经过试验,与现有的方法相比,该算法在提取效率和结果准确性方面都有明显提高.

The Extraction of Catchment and Subcatchment from Regular Grid DEMs

As a fundamental problem in hydrologic analysis, hydrographic patterns extraction including drainage network and catchments boundary has to be done efficiently and accurately. In this paper, a hydrographic patterns extraction approach from regular grid Digital Elevation Models (DEMs) is presented. At first, this paper gives a brief introduction of current hydrographic patterns extraction algorithms based on hydrological flow modeling method, in which the main task is to generate three matrices: elevation matrix without depression, flow direction matrix and flow accumulation matrix. The main part of this paper discusses an algorithm, which extracts a number of catchments and subcatchments properties from depressionless DEMs to assist in the rapid parameterization of hydrologic runoff models. The algorithm firstly identify the catchment area of each river in the grid DEM data. Then it delineates the catchments, and divided them into subcatchments as required. At last the algorithm is tested with a set of DEMs of different sizes, and the result proves that the massive data processing capacity, computing efficiency and result accuracy are better than existing methods.