中文摘要：

坡面形态演化是坡面系统过程作用的体现,是流域地貌系统研究重要内容之一。该文运用复杂网络方法构建坡面形态空间演化结构,探讨坡面系统演变规律。采用近景摄影测量方法得到模拟黄土坡面的9期地形数据,运用面向对象分割方法,得到了7种坡形类型空间分布图。以坡形为节点,边为坡形之间的空间连接关系,构建坡面空间网络图。研究结果得到坡面网络模型属于无标度网络,具有异配网络特征,其中陡坡是坡面网络的关键节点,控制着网络空间结构。网络演化中双直形坡的平均度下降显著,陡坡节点发育影响着系统输沙量。网络结构熵开始急剧增大,经历平缓增大到稳定状态,依据网络结构熵的变化将网络演化分为发育期、发展期和成熟期3个阶段。降雨强度增大使得坡面网络的结构熵变化显著,加剧了坡面系统演化。研究表明复杂网络框架是研究地貌系统演化一种有效途径。

英文摘要：

The evolution of slope is the result of slope process and one of the issues of geomorphic system for drainage basin. In the present study, a complex network method was adopted to build up the spatial structure of slope system in order to explore the evolution rules of slope system. Data were high-resolution digital elevation model（DEM） of 9 stages, which were gathered by close range photogrammetry during different stages of the runoff experiment. Slope form was classified into 7 slope types, i.e. flat slope, steep slope, double-straight slope, double-concave slope, double-convex slope, convex-straight slope and concave-straight slope. Slope unit was further segmented using object-based image analysis method with the terrain factors including slope, plan curvature and profile curvature. Scale parameter of slope segmentation was set to 10 units depending on change rate of local variance on segmentation model. The classification map of slope forms was completed based on the classification rules of slope unit. Slope networks referred to objects composed of slope units and connection between these units. Each node represented slope form which was the terrain condition of sediment transfer. Edges illustrated the spatial link relations between slope forms. Nine slope networks were established in 9 stages, and average degree, degree-relation and structure entropy were taken as network indices to measure network characteristics. Results showed that the degree distribution of slope network fitted power law, so it was a kind of scale-free network. Steep slope was one key node which controlled the structure of network. New nodes preferred to connect with the node with high average degree under gravity erosion, therefore, double-straight slope was apt to transform into steep slope. Moreover, slope network is a disassortative network as minus assortative factor. Slope form with low degree was easily distributed around node with high degree. In the evolution of slope system, new slope forms constantly emerged and network st