基于DEM的横断山县域山区类型划分

Mountainous area divisions at county level in Hengduan Mountains based on DEM

科学界定山地和山区类型可为山区因地制宜施策提供参考。运用均值变点法,确定最佳统计单元面积,利用ArcGIS的空间分析工具处理DEM数据,提取横断山各类山地面积,以县级行政单元对横断山山区类型进行划分。研究表明:使用均值变点法确定移动窗口面积14.98km^2为横断山地地形起伏度最佳统计单元面积;横断山山地面积占比大,山地与非山地面积之比约为94∶6,山地省际空间分异明显,四川省的山地类型以次高山、高山为主,西藏自治区的山地类型以高山、极高山为主,云南省的山地类型以中山和次高山为主;横断山县级行政单元多数是山区县,其中有16个半山区县,6个准山区县,11个显山区县,65个整山区县,只有1个非山区县。整山区县的数量最多,主要分布于横断山地的中部及其以北地区。

Scientifically demarcating mountain types and mountainous areas types can provide reference for mountainous regions according to local conditions. In this study,we use spatial analysis tools of ArcGIS to process DEM data,and extract various areas of mountain types in Hengduan Mountains. In addition,we also divide Hengduan Mountains into different mountainous areas types at county level. The results are as follows：Mean change point method for the second time is used to determine the best statistical window which is demonstrated to be 14 . 98 km2 of mean relief amplitude in Hengduan Mountains. Hengduan Mountains has high proportion of mountainous land,and the ratio of mountainous land to non-mountainous land is 94∶6. However,there is an obvious spatial distribution difference be-tween Yunnan province,Sichuan province and Tibet. Sichuan province is mainly consisted of sub-high mountains and high mountains;Tibet is mainly consisted of high mountains and extremely high mountains;Yunnan province is mainly consisted of middle mountains and sub-high mountains. The counties are mostly mountainous counties in Hengduan Mountains,only including 1 non-mountainous county. There are 16 mid-mount counties,6 quasi-mount counties,11 apparent-mount counties and 65 whole-mount counties. The number of the whole-mount counties is the largest,which mainly distribute in the middle and north in Hengduan Mountains.