高原山区水系结构及连通性初探——以滇池流域为例

基于2000年1∶10 000地形图中水系数据,借助GIS平台,采用Strahler水系分级,选取水系形态、水系密度、水系复杂度及水系连通度等结构指标,探讨了所属高原山区的滇池流域水系空间维度上的特征及其与沿海平原河网的差异性,并分析与评价了流域内水利工程对区域的水系结构及功能的影响,提出了基于连通性内涵的评价指标F,同时在流域内进行了应用。结果表明:滇池流域内水系结构基本满足Horton定律,水系形态在空间维度上的差异性不显著;相比沿海地区,滇池流域的水系密度较低,水系整体发育程度不高;蓄水工程增大了流域水面率,提高了流域调蓄能力,Hurst指数能较好地反映这种变化;连通性评价指标F能较好地反映工程对流域连通性的作用,对其他工程的规划决策及评价具有一定的参考意义。

Preliminary Research on the Drainage Structure and Connectivity of the Plateau Area: A Case Study of Dianchi Lake

According to the 1 : 10000 topographic map in 2000 and the Strahler river classification, the spatial-di-mensional features of Dianchi Lake basin which belongs to plateau mountainous area and its differences with coastal plain river network were analyzed based on GIS platform from aspects of drainage pattern,river density, river system complexity and drainage connectivity. Moreover, the influences of water conservancy projects on the regional river structure and function were evaluated, and an evaluation index F based on connectivity connotation was proposed and applied to the basin. Results showed that:1) the river structure in Dianchi Lake basin conforms with Horton law, and the difference of drainage pattern in spatial dimension is not significant;2) compared with those of coastal areas, the drainage density is low in the basin, and the drainage development degree is not high;3) reservoir pro-jects increase the rate of water surface and storage capacity in the basin, which can be reflected well by the Hurst index;4) the evaluation index F could well reflect the role of projects in basin connectivity.