关键词: 数字高程模型, 数字水系模型, 洼地, 平地, 出流代价, 流域特征

Abstract:

The extraction of drainage network,catchment properties information and the simulation of distributed hydrological process of catchment based on DEM have been a hot spot over the last ten years,the construction of digital drainage network model of catchment based on DEM and the extraction of drainage network of catchment are important premises of simulating catchment's distributed hydrological processes.The structure of digital drainage network model suitable for extracting catchment properties and simulating hydrological process of catchment is proposed.The methodology and algorithm suitable for the topography of complex catchment are designed to overcome the shortcomings in the efficiency,validity and effects of existing methods,such as classification of raster drainage,classification and amalgamation of depression area,valid fill-up of depression,classification of flat area,the method of out-flow cost of constructing direction and order of raster drainage in flat areas of river valley,which considers ambient terrain and astringency toward potential waterway.These methodologies and algorithms are applied and implemented in the software systems developed,and the systems are successfully used in constructing digital drainage network model and extracting catchment properties information including classified waterway,subbasins raster,the vector polygon borders and properties parameters of subbsins of Huangtuling catchment in Zhejiang province.The result of test shows the proposed methods in the paper can cope with and handle various catchments with complex terrain,the drainage network extracted matches well with the natural drainage network in Huangtuling catchment.The shortcoming of parallel,odd waterways and deformation waterways created in the existing methods can be effectively overcome and solved.The research result can provide a basis for the simulation of the distributed hydrological processes for catchment.

Key words: Digital Elevation Model, digital drainage network model, depression area, flat area, out-flow cost, catchment properties