基于DEM的贵州沟壑特征及其空间分异规律研究

Research on Gully Characteristic and Spatial Differentiation Rule in Guizhou Province Based on DEM

采用USGS发布的贵州省1∶24万DEM数据,以贵州省喀斯特高原二级流域单元及地(州、市)行政单元为界线,分别采用集水面积阈值1 000和500来计算沟壑密度,构建基于DEM的沟壑特征信息提取模型。并通过贵州省1∶25万水系及2005年贵州省石漠化空间分布数据进行了比对,分析了集水面积阈值随喀斯特地貌复杂度变化而变化的规律,并研究了汇流阈值与沟谷网络总长度的量化关系。尝试摸清了河网密度、石漠化分布与沟壑密度之间的关系,并对贵州喀斯特流域地貌的整体空间分布特征提出了一个更新的认识。

Based on the data from digital elevation model with the ratio of 1 ： 240000 which was published by the U. S. geological survey and taking the secondary river unit and district （state, city） administrative unit in the karst plateau of Guizhou province as boundary line, the article calculates the gully density by the drainage area threshold of 1000 and 500 respectively and constructs a DEM--based gully characteristic information extracting model. Through the comparison of 1 ： 250000 water system and spatial distribution data of karst rocky desertification during the year 2005 in Guizhou province, the article analyzes the change rule of drainage area threshold according to the karst landform complexity and also studies the quantitative relationship between conflux threshold value and total gully network length. The article tries to figure out the relationship among drainage density, distribution of karst rocky desertification and gully density. In addition, the article aims to have a new understanding of the overall space distribution characteristic in karst river basin landform in Guizhou province.