周访滨, 肖智文, 刘学军, 马国伟, 张珊珊. 栅格DEM山顶点提取的坡向分布特征法[J]. 武汉大学学报 ( 信息科学版). doi: 10.13203/j.whugis20210479
引用本文: 周访滨, 肖智文, 刘学军, 马国伟, 张珊珊. 栅格DEM山顶点提取的坡向分布特征法[J]. 武汉大学学报 ( 信息科学版). doi: 10.13203/j.whugis20210479
ZHOU Fangbin, XIAO Zhiwen, LIU Xuejun, MA Guowei, ZHANG Shanshan. Method for Mountain Peak Extraction of Grid DEM Based on Aspect Distribution Feature[J]. Geomatics and Information Science of Wuhan University. doi: 10.13203/j.whugis20210479
Citation: ZHOU Fangbin, XIAO Zhiwen, LIU Xuejun, MA Guowei, ZHANG Shanshan. Method for Mountain Peak Extraction of Grid DEM Based on Aspect Distribution Feature[J]. Geomatics and Information Science of Wuhan University. doi: 10.13203/j.whugis20210479

栅格DEM山顶点提取的坡向分布特征法

Method for Mountain Peak Extraction of Grid DEM Based on Aspect Distribution Feature

  • 摘要: 山顶点提取方法决定着山体部位划分结果的正确性和微地形自动分类效率。以高程和等高线为参考提取山顶点方法存在伪山顶点剔除不完全和局部山顶点丢失的问题,依据山顶点邻域坡向呈均匀分布规律提出了基于坡向分布特征的山顶点提取方法,构建了以山顶点为中心的邻域坡向顺时针逐渐递增模型,并以山脊线拟合和深度优先搜索(Depth First Search,DFS)算法的递推思想,剔除提取结果中的伪山顶点。顾及实体DEM地形破碎对提取方法的影响,采用了模拟DEM和实体DEM分别实验和分析。实验结果表明,坡向分布特征法避免了传统基于封闭等高线提取山顶点时主观选取阈值的不确定性;模拟DEM因其连续、光滑,山顶点提取准确率可达到100%,而实体DEM沿用模拟DEM机制因其地形破碎导致不可适性,通过调整坡向分布约束条件可予以改善,实验提取准确率平均可达到96.1%。

     

    Abstract: Objects:  The mountain peak extraction technology determines the accuracy of the hill position classification results and the efficiency of automatic classification of micro-landform. On account of the limitations of elevation and contour lines, such as loss of local mountain peaks and incomplete removal of false mountain peaks, it must be mined other landform factors to express the distribution feature around the mountain peaks.   Methods:  Based on the uniform distribution feature of the aspect around the mountain peaks, an efficient mountain peak extraction model is proposed in this paper, in which the aspect is centered on the mountain peak and gradually increases clockwise. Moreover, according to the ridge line fitting method and the recursive thought of depth first search algorithm, the false mountain peaks in the extraction results are removed, while the real mountain peaks are retained.   Results:  Considering the negative influences of the terrain fragmentation of the entity DEM, this paper experiments and analyzes with simulated DEM and entity DEM respectively. The result shows that the proposed method overcomes the uncertainty of subjective threshold when extracting mountain peaks based on closed contour lines. The accuracy of extracting simulated DEM mountain peaks can achieve up to 100% due to its continuity and smoothness. Considering that the terrain fragmentation of entity DEM will make it ill-posed, we improve it by adjusting the aspect distribution constraint condition and obtain average extraction accuracy of 96.1%.   Conclusion:  An efficient mountain peak extraction model is proposed in this paper based on the digital terrain analysis technology and the uniform distribution feature of the aspect around the mountain peaks, and the topographic feature points are extracted from the perspective of terrain geometry. Compared with the traditional mountain peak extraction methods, the method based on aspect distribution feature is relatively accurate and simple, effectively reducing the false mountain peaks appearing in the results.

     

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