基于SRTM的沅江流域水系提取与分形特征研究

Study on River Systems Extraction and Fractal Characteristics of Yuan River Basin Based on SRTM

摘要: 为完善沅江流域治理的基础数字地形信息，同时为沅江流域地理信息系统建设提供一定的信息支持，基于沅江流域的SRTM数据，利用ArcGIS软件的水文分析模块和提取分析模块等，提取了沅江流域的河网水系，同时采用网格法和分叉比河长比2种方法，计算了沅江流域的水系分维数，对比分析了网格法和分叉比河长比两种方法，并判断了此流域的发育情况、构造运动程度和侵蚀旋回阶段。研究表明，两种方法计算的沅江流域水系的分形维数分别为1.9327和1.9412，满足分支比河长比计算方式大于网格法计算方式的规律，前者计算工作量大于后者，但可靠度较后者高。从水系分维值可以判断出研究区的流域发育阶段属于老年期，该水系的发育情况较为完善，构造运动强烈，属于侵蚀旋回四级阶段。

Abstract: To perfect Yuan River basin based digital terrain information, at the same time for Yuan River basin geography information system construction to provide certain information support, based on Yuan River basin SRTM DEM data, using the hydrological analysis module and extracting analysis module of ArcGIS software, etc., to extract the Yuan River drainage basin, at the same time, using the grid method and bifurcation is longer than the river than the two methods. The fractal dimension of the river system in the Yuanjiang River Basin was calculated, the grid method and the bifurcation to river length ratio were compared and analyzed, and the development of the basin, the degree of tectonic movement and the cycle stage of erosion were judged. Research shows that: the fractal dimensions of the Yuanjiang River drainage system calculated by the two methods were 1.9327 and 1.9412, respectively, which satisfied the rule that the branch-to-river ratio calculated by the two methods was larger than that calculated by the grid method. The calculation workload of the former method was greater than that of the latter, but the reliability of the former method was higher than that of the latter. According to the fractal dimension of the river system, the development stage of the basin in the study area belongs to the old age, the development of the river system is relatively perfect, the tectonic movement is strong, and it belongs to the four stages of erosion cycle.