基于DEM的流域水系分维计算与结果分析

利用ArcGIS8.3和ArcVIEW3.2中的水文分析模块,根据不同最小河流长度,提取晋江流域河网信息,采用传统的网格法计算提取的不同河网的分维,研究以最小河流长度所提取的不同河网密度与分维的关系,确定晋江流域分维,分析流域地貌的演变。

Study on Reationship Between Extracted River Network and Fraetal Dimension Based on DEM

River network is a kind of natural fractal. It has become more and more popular in deriving basin characteristics from DEM. The Jinjiang River basin is selected as a study area. The river networks are extracted from DEM at a scale of 1∶100 000 with ten different minimum river lengths varying from 30m to 1 500m. The extraction is based on the function of the ArcGIS8.3 and ArcVIEW3.2 which can get much more information of the dimensions of the river networks. The fractal dimensions of the river networks is investigated by the box counting method firstly,and then the relationships between different minimum river lengths and fractal dimensions based on DEM are discussed. It depicts that there is a critical minimum river length for the determination of the fractal dimension of a river network. The value of the Jinjiang River basin is 150m. The results also show that methods of both box counting method and the Horton's Law are feasible to study the fractal dimensions and it is revealed that the evolution of physiognomy in the Jinjiang River basin is in its initial stage.