西双版纳土地利用/土地覆被变化时空格局分析

Spatial-Temporal Pattern Analysis of Land Use and Land Cover Change in Xishuangbanna

西双版纳土地利用/土地覆被变化对于区域土地资源合理利用和生态环境保护以及边境安全保障具有重要意义。基于Landsat TM/ETM遥感数据,采用决策树分类方法,获得西双版纳1990年、2000年和2010年3期的土地利用/土地覆被分类数据;从结构变化、类型变化、空间变化3个角度,系统分析1990-2010年间西双版纳的土地利用/土地覆被时空变化规律,并对轮歇地、茶园和橡胶园3个典型地类进行了重点讨论。研究表明:①西双版纳土地利用/土地覆被呈现以"林地-园地-耕地"为主导的地域结构特征,有林地是最为重要的土地覆被类型,橡胶园是最为主要的土地利用类型;②1990-2010年间,土地利用/土地覆被变化速度呈加快趋势,土地利用强度呈增加趋势,近10年来则更为显著;③1990-2010年间,土地利用/土地覆被变化的主要特征是有林地不断减少,橡胶园、旱地和茶园不断增加;有林地为面积减少最多的地类,橡胶园为面积增加最多的地类,轮歇地为增速最快的地类,灌木林地为减速最快的地类;④1990-2010年间,土地利用/土地覆被类型发生转化的地类主要是轮歇地、灌木林地和有林地,主要的转化方向是轮歇地向有林地和灌木林地转化,橡胶园和茶园的主要来源是有林地和灌木林;⑤1990-2010年间,土地利用/土地覆被空间变化较显著的地类是有林地、灌木林地、橡胶园、茶园和轮歇地;有林地呈以减少为主要特征的"南退北进"的空间变化特征,灌木林地呈先增加后减少为主要特征的"西退东进、南退北进"的空间变化特征,橡胶园呈以增加为主要特征的"以景洪市区为中心,北上南进,西拓东扩"的空间变化特征。

The study of land use and land cover change in Xishuangbanna is significant to the reasonable land resources development, regional and ecological environmental protection and border security. Land use and land cover classification maps were extracted by interpreting Landsat TM/ETM images from 1990, 2000, and 2010 using a decision tree model classifier based on 3S technology. Spatial-temporal changes in land use and land cover were analyzed systematically from the perspective of structure, type conversion and spatial pattern, especially focusing on swidden land, tea garden and rubber plantation. We found that： ①Regional structure of land use and land cover in Xishuangbanna was forest land - garden plot - cultivated land; woodland is a major land cover type and rubber plantation dominates land use. ②Between 1990 and 2010, changes in land use and land cover accelerated. Land use intensity was enhanced generally, especially in the past 10 years. ③From 1990 to 2010, the main characteristics of land use and land cover change were woodland （decreasing） and rubber plantation, dry land, and tea garden （increasing）. Woodland experienced the largest area reduction, while rubber plantation had the largest area increment. Swidden land showed the fastest growth, and shrubland the fastest deceleration. ④ The major conversion land types were swidden land, shrubland, and woodland. Swidden land was mainly transferred into woodland and shrubland, and woodland and shrubland were the main sources of rubber plantation and tea garden. ⑤ Woodland, shrubland, rubber plantation, tea garden and swidden land were in the significant changing distribution from 1990 to 2010. Woodland and shrubland were both destructed mainly in the southern and western regions, while woodland with gradual leading decreasing spatial pattern and shrubland from increasing to decreasing. The distribution characteristics of rubber plantation varied from concentrated to dispersed and expanded further in all directions with Jinghong City as an expanding center.