贵州喀斯特地区河网分布规律及其主控要素分析

为揭示喀斯特地区河网的空间分布规律及其与主控自然要素的关系,运用GIS为主要分析手段,以贵州为研究样区,通过数字矢量化1∶5万水系图、降雨量分布图、地貌类型图、坡度图、岩性图等,进行空间叠加分析,定量计算了不同类型区河网密度值,分析了贵州河网的空间分布特点。结果表明:贵州平均河网密度为781.84m/km2,受构造运动影响较为明显,整体呈现出"东密西疏"的特点。非碳酸盐岩地区河网密度为1000.43 m/km2,石灰岩地区为597.16 m/km2,白云岩地区为779.41m/km2,河网密度与岩性具有明显的相关性,非碳酸盐岩地区河网密度要远远高于碳酸盐岩地区,白云岩地区河网密度高于石灰岩地区;在垂直空间上,坡度≤2°时,河网密度最大,为1237.36m/km2,而坡度≥25°时,河网密度为379.37m/km2,随着坡度的增加河网密度明显降低。

Drainage Network Distribution and Its Master Natural Factors in Guizhou Province

In order to analysis the characteristics of the spatial distribution of drainage network in karst area,the mean value of drainage network density in each type was calculated based on the overlay analysis of 1:50000 drainage network map and precipitation pattern,landform map,tectonics chart,slope map,lithology diagram,and the characteristics of spatial distribution of drainage network was analysed,by using GIS as the major analysis methods in Guizhou province.By calculating,the average density of drainage network is 0.78 km/km2,affected by tectonic movement,it presents the characteristic of dense in eastern.The drainage network density in non-carbonate area is 1000.43 m/km2,the limestone area is 597.16 m/km2,the dolomite area is 779.41 m/km2,the drainage network density and lithology has an obvious correlation that drainage network density in non-carbonate area is far higher than carbonate area,and drainage network density in dolomite area is higher than limestone area;In vertical space,When the slope is ≤2°,drainage network density is the largest,1237.36 m/km2,and when slope is≥25°,drainage network density is 379.37 m/km2,with the increase of slope,the drainage network density decreases obviously.