基于SRTM-DEM的我国地势起伏度统计单元研究

Statistical Unit of Relief Amplitude in China Based on SRTM-DEM

地势起伏度是描述地貌形态的重要指标,也是地质灾害评价的最佳地形指标,其计算关键在于统计单元的选择。本文以SRTM-DEM数据为例,对统计单元计算模型的准确性和适用性进行了详细研究,提出了中国地势起伏度的最佳统计单元。研究分析表明:采用人工作图法判断最佳统计单元时应该寻找趋于稳定的点;人工作图法和均值变点法是相对比较有效的方法,最大高差和模糊数学法已不适用;基于90 m分辨率的SRTM-DEM数据提取中国地势起伏度的最佳统计单元面积为2.25 km2。

Relief amplitude is an important indicator to describe geomorphic morphology and the optimum topographic indicator for geological hazard assessment. The calculation of relief amplitude lies in the choice of statistical unit. Taking SRTM-DEM data for example,this paper researched the accuracy and applicability of calculation model for statistical unit in detail,and determined the optimum statistical unit of relief amplitude in China. Research shows that:We should look for a stable point when using artificial drawing method to determine the optimum statistical unit. Moreover, artificial drawing method and mean change point method are more effective,compared to maximum elevation difference method and fuzzy mathematics method. The optimum statistical unit area of relief amplitude in China based on SRTM-DEM data of 90 meters resolution is 2.25km2.