黔桂喀斯特山地与山区类型划分技术与应用

Technology and Application of Mountainous Area Divisions in Qian-Gui Karst Areas

科学界定山地和山区类型是认识山地、因地制宜促进山区可持续发展的基础,可为山区分类开发、分类施策提供依据。本文采用均值变点法确定滑动窗口尺寸,运用空间分析工具对SRTM进行处理以获取山地坡度、起伏度,并提取了黔桂喀斯特各类山地空间范围和规模,以此对县级层面黔桂喀斯特山区类型进行了划分。主要结论如下:(1)二次使用均值变点法确定移动窗口面积与平均地形起伏度拟合的对数曲线拐点,其表征的是黔桂喀斯特山区地形起伏度最佳统计单元—移动窗口面积为6.50 km^2。(2)黔桂喀斯特山地占比大,山地与非山地面积之比约为89:11,且山地省际空间分异明显,贵州喀斯特山地以中山、中低山为主,占贵州部分的57%;而广西喀斯特山地以丘陵为主,占广西部分的59%。(3)黔桂喀斯特山地区均为山区县,其中,18个纯丘陵县、10个半山区县、15个准山区县、21个显山区县、32个整山区县。整山区县个数多,多分布于乌蒙山区和黔桂峰丛洼地山区,多数为国家扶贫开发工作重点县。

Reasonably demarcating mountain types and mountainous areas can provide reasonable basis for exploring land resource and carrying out policies in mountainous regions, respectively. In this study, mean change point method was used for best statistical window. We obtain the slope and the degree of fluctuation form SRTM data by using spatial analysis tools, and extract spatial scope and scale in Qian-Gui karst areas. In addition, we also divide Qian-Gui karst areas into different types of mountainous area at county level. The results are as follows： （1） quadratic mean change point method is used to determine the logarithmic curve inflection point of which the best statistical window is demonstrated to be 6.50 km2 between changing window size and mean relief degree in Qian-Gui karst areas. （2） Qian-Gui karst areas have high proportion of mountainous land, and the ratio of mountainous land to non-mountainous land is 89：11. However, there is an obvious spatial distribution difference between Guangxi and Guizhou province. Karst mountain region in Guizhou is mainly consisted of middle-low mountain and middle mountain which account for 57%. Instead, the hill which accounts for 59% is the primary part of Guangxi karst mountain region. （3） Qian-Gui karst areas are all mountainous counties, including 18 pure hilly counties, 10 semi-mountainous county, 15 quasi-mountainous counties, 21 apparent mountainous counties and 32 entire mountainous counties. The entire mountainous county that is almost national key counties for poverty alleviation and development distribute majorly in Wumeng mountainous areas and Qian-Gui karst peak-cluster depressions.