顾及空间特征的地形特征点提取方法

Terrain feature point extraction method considering spatial characteristics

针对传统地形特征点提取方法未能全面顾及地形特征点空间特征的问题,该文提出一种顾及空间特征的地形特征点提取方法。该方法在系统分析地形特征点的空间分布差异性、空间耦合性、层次等级性的基础上,采用均值变点法确定适宜阈值,利用成熟的水文分析法提取沟谷线和山脊线。在此基础上,通过窗口分析、矢量分析等方法实现对山顶点、鞍部点、脊线源点、脊线交点、径流源点、径流节点、流域出水口点的有效提取和分级。以福建省九龙江支流吕凤溪流域30 m空间分辨率数字高程模型进行实验。从目视解译、地形模型对比、分级适宜性3个角度对提取结果进行评价,同时分析了空间分辨率对地形特征点提取的影响。实验结果表明,所提方法能有效保证地形特征点提取结果的准确性,空间分辨率对地形特征点提取结果的总数目、最高级别和分级数目以及空间位置具有重要影响。

Aiming at the problem that the traditional method of extracting terrain feature points fails to fully consider the spatial characteristics of terrain feature points,a new method of extracting terrain feature points considering spatial characteristics is proposed.On the basis of systematically analyzing the spatial distribution difference,spatial coupling and hierarchical gradation of topographic feature points,this method uses the mean change point method to determine the appropriate threshold value,uses mature hydrological analysis method to extract valley line and ridge line.On this basis,the effective extraction and classification of Peaks,saddle points,ridge source points,ridge intersection points,runoff source points,runoff nodes and drainage outlet points are realized by means of window analysis and vector analysis.Experiments on a 30 m spatial resolution digital elevation model in Lvfeng Stream basin,Jiulong River tributary,Fujian Province.The extraction results were evaluated from three perspectives:visual interpretation,terrain model comparison and classification suitability.At the same time,the influence of spatial resolution on feature point extraction is analyzed.The experimental results show that the proposed method can effectively ensure the accuracy of terrain feature points extraction.The spatial resolution has an important influence on the total number,the highest level and the number of classification as well as the spatial location of the terrain feature points.