基于DEM的2种提取地形特征线算法对比研究

以云南省昭通市昭阳区1∶5万的DEM规则数据作为数据源,分别利用平面曲率与坡形组合提取法(基于平面曲率、坡向变率)、地形地表几何形态分析和流水物理模拟结合分析法提取其地形特征线(山脊线、山谷线),并根据提取效果选取研究区的西北区作为效果比对样区.对3个提取效果进行对比后发现:①分级阈值的合理判定是正确提取地形特征线的关键；②基于地形地表几何形态分析和流水物理模拟结合分析法提取的地形特征线效果最佳,而基于平面曲率、坡向变率提取的地形特征线效果各有优缺.

Comparative Study on Two Line Algorithm Methods of Terrain Feature Extraction Based on DEM

Taking 1:50000 DEM image of Zhaoyang District of Zhaotong City in Yunnan Province as data sources,separately using plane curvature and slope shape combined extraction method(based on plane curvature,slope variability),terrain surface geometry analysis and flowing water physical model analysis to extract the study area topography lines(ridge lines,valley lines),and choose northwest study area as the contrastive sample area in view of extraction effects,compared the three extraction effects.The results showed that:(1) A reasonable classification threshold is the key to correctly extract topography lines;(2) The best effects of topography lines are extracted based on terrain surface geometry analysis and flowing water physical model analysis,while topography lines extracted from plane curvature and slope variability have advantage and disadvantage respectively.