典型河网形态特征与分布

Morphological feature and distribution of typical river networks

河流网络系统是地表流水地貌的重要组成部分,具有开放性、随机性、自相似性等特点。不同地区具有其独特的自然环境条件,从而形成了各种外观上迥然不同的河网形态。本文以卫星地图上的平面拓扑结构为依据,划分了3种典型河网形态:羽状河网、叶状河网和枝状河网,并在Horton定律的基础上对这3种典型河网形态的平均Horton比和流域外型参数进行了定量统计分析。此外,进行了中国大陆范围内各种典型河网形态的分布研究,从而探讨了影响河网形态产生的环境条件。

Three typical river network morphologies including Feather, Leave and Branch, were classified from planar topological view in satellite images in order to study the differences of evolutionary mechanism among them. The Horton＇ s ratios and basin shape parameters of these morphologies were calculated. The results indicate that the average bifurcation ratios, length ratios and area ratios tend to be constant 4, 2 and 4 respectively for large river networks, which are independent of environmental conditions. However, the differences of the Horton＇ s ratio among small river basins were enormous, so that the Horton ＇ s ratio can be used to express the influence of environmental conditions in small scale. On this basis, the distributions of various typical river networks morphologies in China were studied for investigating the influence of environmental conditions on morphological feature.