中文摘要：

山脊线是构成地形骨架的主要地形特征线之一,它与沟谷线共同控制着地形整体走势。山脊表现为与沟谷类似的层次分支结构,但却不具备沟谷线水流方向明确的特性。本文在借鉴沟谷线分级思想基础上,提出一种基于DEM脊点跟踪的山脊线编码分级方法,通过修正流域边界线提取山脊线,找到各等级脊线起始点,搜索并编码出相应等级的完整山脊线。通过宜君和韭园沟两个小流域进行验证,并与流域边界最高级分级法对比。结果表明,本文编码方法可以有效反映出山脊线层次,山脊线等级划分相对细致,与同一阈值下沟谷线等级匹配性较好。该研究可为地形结构特征分析提供方法参考,为多尺度地形综合提供技术支撑。

英文摘要：

Being one of key features constructing the terrain skeleton,ridge lines interworking with valley lines control the terrain movements on the whole. Despite being with many branches of different orders similar to valley lines,the ridge lines don＇t extend like the direction of valley lines which flow from high locations to low ones and converge to the outlet. Referring to the thought for classifying valley lines,a DEMs-based method for ordering and coding ridge lines was proposed to search and order them by extracting them from modified watershed boundary,finding the starting point of each ridge line being of different order,then searching and encoding each ridge segment with the starting point＇s order. Taking two watersheds named Yijun and Jiuyuangou as test areas and one existed algorithm ordering ridge lines named highest-level watershed boundary as comparison,the method presented in this paper was verified and evaluated. The results show that the method can describe the relationship of ridge lines with different orders clearly with more details and the ridge lines ordered by this method match the corresponding order valley lines extracted with same accumulation threshold value and ordered by Strahler approach very well. The research is helpful to analyze the terrain structure based on terrain features and construct multi-scale DEMs.