三峡库区水系形态分形特征及地貌发育指示

Fractal Characteristics of River System Morphology and Indication of Landscape Evolution in the Three Gorges Reservoir Area,China

水系结构特征是研究水文过程与地貌过程的基础,基于DEM数据和Arc GIS软件平台,运用河流发育系数、河流不均匀系数和信息维数分析了三峡库区水系结构特征、形态分形特征及其地貌发育指示意义。结果表明：（1）三峡库区水系河道主要以1级和2级为主,分别占河道总数的77%和17%;1级水系长度最长,占水系总长度的51%,2级-5级水系长度分别占水系总长度的26%、13%、4%和6%。（2）三峡库区各级水系发育程度不一致,水系发育系数分别是1级水系8.62、2级水系4.41、3级水系2.22和4级水系0.72。（3）三峡库区库首、库中和库尾两岸汇入干流的水量均存在差异,不对称系数分别是2.21、0.39和0.87。（4）三峡库区库首、库中和库尾水系分形维数分别是1.027、1.026和1.022,地貌发育均处于幼年期。

The study on the characteristics of river system structure is the basis for understanding the hydrological and geomorphologic processes. River development coefficient, non-uniform coefficient and the box- counting dimension are adopted to investigate the river system structure and fractal characteristics in the Three Gorges Reservoir area of China, based on the DEM data and Arc GIS software platform, and further analyzed landscape evolution significance. The results shown that 1） river channels are mainly composed of class 1 and class 2, form perspective of quantity, account for 77% and 17% of the total number of river channels, respectively. The total length of class 1 reaches is longest, accounted for 51% of the total length of drainage, and class 2 to 5 reaches accounted for 26%、13%、4% and 6%,respectively. 2） Drainage network development inconformity in this region, class 1 to 4 river system development coefficient is 8.62, 4.41, 2.22 and 0.72, respectively. 3）Water into the main stream（Yangtze River） from two sides tributary unbalance at each parts, the non-uniform coefficient of head, middle and tail part of The Three Gorges Reservoir area is 2.21, 0.39 and 0.87, respectively. 4） Box- countingdimension value is 1.027, 1.026 and 1.022 of head, middle and tail part of the Three Gorges Reservoir area, each parts of this region all in infancy of geomorphic evolution.