喀斯特山地植被变化的地形分异特征——以贵州安龙县为例

The Topography Differentiation Characteristics of Vegetation Change in Karst Mountainous Area——A Case Study in Anlong County of Guizhou Province

为了解喀斯特山地植被变化的地形分异特征,选择安龙县1990、2000以及2009三年的遥感数据提取NDVI,基于DEM生成地形因子,应用GIS叠加分析其变化特征。结果表明:2000—2009年与1990—2000年相比,(1)全县NDVI值正向变化所占比例由最小变为最大;(2)中高山区的正向变化增幅最大和无明显变化减幅最大,低山丘陵区负向变化减幅最大;(3)斜坡、陡坡和险坡的负向变化减幅较平坡和缓坡的高;(4)阴坡、半阴坡、半阳坡正向变化增幅较阳坡和无坡向的大。为改善当地的生态环境提供基础数据,同时为贵州喀斯特地区植被生态环境监测等提供技术参考。

To understand differentiation characteristics of vegetation change in Karst mountainous terrain,the remote sensing data of Anlong County in 1990,2000 and 2009 were selected to extract NDVI,the terrain factor was generated based on DEM,and the variation characteristics were analyzed by overlay GIS. The results showed that years from 2000 to 2009 compared with years from 1990 to 2000,firstly,the proportion of positive change of NDVI value in the county changed from minimum to maximum.Secondly,the increase of positive change of such elevation zone as ≥ 1600 m was the largest,at the same time,the decrease of its no obvious change was the biggest,the decrease of negative change of such elevation zone as 700 ～ 1000 m was the largest. Thirdly,compared with slope zones of ≤10°and10 ～ 20°,the decrease of negative change of slope zones of 20 ～ 30°,30 ～ 40° and ≥40° were high.Lastly,compared with gradient zones of-1,157. 5 ～ 202. 5° and 202. 5 ～ 247. 5°,the increase of positive change of gradient zones of 337. 5 ～ 22. 5°,22. 5 ～ 67. 5°,292. 5 ～ 337. 5°,67. 5 ～ 112. 5°,247. 5 ～ 292. 5° and 112. 5 ～ 157. 5° were high. They were the basic data for improving the local ecological environment. At the same time,they were the technical references for the ecological environment monitoring of the vegetation in Karst region for Guizhou.