基于DEM的地形因子分析与岩性分类

Topographic variable analysis and lithologic classification based on DEM

地形因子作为对地形地貌特征进行数字表达的定量参数,对岩性识别精度的提高具有重要的意义。在对已知岩性类别区域的高程、坡度、剖面曲率、地表粗糙度和地表切割深度等10个地形因子的分类有效性和相关性进行评价的基础上,对地形因子进行筛选并将最佳尺度下的地形因子用于岩性的分类。结果表明,高程、剖面曲率、地表切割深度、地表粗糙度和平面曲率这5个地形因子的组合更具良好的分类效果,且都对应有识别性最好的岩性。在识别岩性类别时加入充分表达其地形特征的最佳地形因子组合有利于提高岩性的识别与分类能力。

Lithologic identification and classification can provide important basic information for regional geological survey and mineral resource exploration. Topographic variables constitute the quantitative parameters of digital expression for topography,and are very important in improving the accuracy. Based on the classification validity and correlation of 10 topographic variables such as elevation,slope,profile curvature,surface roughness,and surface cutting depth in the known lithologic area,the authors screened the topographic variables and used the variables under the best scale for the classification of lithology. The result shows that the combination of elevation,profile curvature,surface cutting depth,surface roughness and plane curvature is very useful and,in terms of the capability of identification,each variable has the corresponding lithology. The adding of the best terrain variables combination to fully express terrain characteristics in identifying each type of lithology is helpful to improving the recognition and classification of lithology.