不同地形分级下的尉犁县土地覆被变化特征分析

选取新疆尉犁县作为研究区,以1980年和2007年两个时相Landsat MSS/TM遥感影像及1∶5万地形图为主要信息源,利用遥感图像处理技术和GIS空间分析技术,定量分析了研究区1980—2007年近30 a地形(高程和坡度)分级下的土地覆被时空格局变化特征。研究结果表明,耕地、林草地、水域及居民点和工矿用地变化明显,耕地主要是由林地草地转入,水域主要转为林草地;居民点和工矿用地向高海拔区域扩张;耕地与居民点和工矿用地在坡度分布上具有耦合性,二者变化趋势趋于一致,均向坡度增大的区域蔓延;林草地在坡度小于3°区域面积增加明显,而在坡度大于3°区域面积有减少趋势;水域面积整体呈缩减趋势。说明利用地形图和社会经济辅助数据来预测区域内土地覆被空间分布已成为可能。

Land Cover Changes on Different Topographic Grades in Yuli County

Based on two Landsat MSS/TM remote sensing images from 1980 to 2007 and 150000 topographic map,a quantitative research on land cover spatial temporal changes pattern of different elevation and slope grades of Yuli County during 1980-2007 was conducted with remote sensing and geographic information system technologies.Results showed that (1)Cropland,wood-grassland,water body,built up land changed prominently during the past three decades,cropland was mainly converted from wood-grassland,water body was mainly transferred into wood-grassland;(2)Built-up land expanded in high elevation area;cropland and built-up land distributed consistently on each gradient,change direction of both land covers was identical,and expanded into the region of steeper slope;(3)Wood-grassland increased dramatically at locations below 3,but it showed a decline trend at position above 3;(4)Water body kept shrink across the whole region.It is feasible to predict the spatial distribution of land cover based on topographic data,remote sensing images and social economic data.