西双版纳地区土地利用的空间分析

利用西双版纳地区2003年TM数据，对土地利用结构及土地利用与海拔、坡度、水系等自然地理要素相互关系的空间进行分析.结果表明，耕地、林地和草地是该地区土地利用的主体，其中林地面积13 420 km²，占研究区总面积的74%；草地面积3 251 km²，耕地面积2 332 km²，分别占13%和18%.林地、耕地和草地面积随海拔高度具有单峰变化的曲线特征，在海拔1 000～1 200 m处林地分布最多，耕地和草地面积达到峰值时的海拔约为900 m.受人为活动影响强的用地类型坡度指数较低，城乡建筑用地和耕地的坡度指数为5°和14°，人为活动影响较弱的林地草地坡度指数较高，分别为22°和20°.河谷内随缓冲距离增加，土地利用呈现规律性变化，耕地、城镇居民点、未利用地3种土地利用方式主要集中在河谷底部近水域处，远离河谷林地草地组分增加明显.西双版纳地区自然生态系统相对原生，具有林地为基质，河流为廊道，坝区、沟谷农业景观镶嵌分布的特点.

Spatial analysis on land use in Xishuangbanna

Based on remote image and GIS technology, this paper analyzed the relationships between land use system and natural topographic factors such as elevation, slope, and river system in Xishuangbanna. The results showed that the land use system in the study region was dominated by forestland, cropland and grassland. The area of forestland was 13 420 km2, accounting for 74% of the total, and that of cropland and grassland was 3 251 km2 and 2 332 km2 , accounting for 13% and 18% of the total, respectively. The areas of these three land use types varied with elevation in single-peaked curve. Forestland mainly distributed around the elevation of 1 000~1 200 m, while cropland and grassland centralized at the elevation of 900 m. Urban land and cropland, which were greatly influenced by human activity, had lower slope index than forestland and grassland. Besides elevation and slope, river system in valley had effects on land use condition. With increasing buffer distance in valley, a strong spatial pattern of land use type was presented, i.e., cropland, urban land and unused land concentrated greatly adjacent to water, while forestland and grassland were far away from valley. A landscape with relatively primary status, which was comprised of forestland as matrix, river as corridor, and cropland as patch, would come into being.