基于树形结构的地形骨架线分级方法研究

Skeleton line gradation method based on tree structure

以绥德韭园沟流域1∶104的数字高程模型(DEM)数据为例,提出了一种基于树形结构的地形骨架线——山脊线的分级方法.首先,依据不同尺度间流域的空间包含关系构建树形结构模型;其次,选取能够代表流域特征信息的流域面积、起伏度以及流域在"树"模型中的位置3个特征参数作为山脊线分级的依据指标,对其进行标准化处理,并通过树形结构模型对这些指标进行综合分析;最后,根据河网分级与支流数确定山脊线等级数,并运用K-Means聚类分级法对山脊线等级进行分级,对分级结果进行对比验证.结果表明:该方法获得的山脊线分级能够准确反映研究样区的地形特征,基于"树"形结构的山脊线分级取得了较好的效果.

In this paper,based on tree structure model,a new method of skeleton gradation namely ridge line gradation was proposed.The method was applied to 1∶104 DEM,which is located in Jiuyuangou area in northern Shaanxi.The study was divided into three stages.Firstly,tree structure was constructed based on the spatial relationships among different scales.Secondly,three standardized parameters named watershed area,waviness,and watershed location in the tree structure were taken as the indexes of ridge line gradation,and were analyzed based on tree structure.Lastly,the number of ridge line gradation was identified by river network and tributary number,and then ridge line gradation was determined using the method of K-Means cluster classification.The division result was contrasted with He＇s method,and the new method was proved to be a precise and quick division approach.The results show that the topographic feature can be reflected correctly by the extracted ridge line gradation.For the first time,this paper combined tree structure with skeleton grade division.Novel methods introduced here may guide future research directions for digital terrain analysis.