The Change Of Land Use And It's Ecological Effect In Longitudinal Range-Gorge Region

The Longitudinal Range-Gorge Region of Yunnan province is the Hengduan Mountains in southwest China and its adjacent north—south mountain-river areas.In this paper, Longitudinal Range-Gorge Region was selected as a study area, the land use data in 1986 and 2000,and DEM were applied, the natural data, social information and economy statistical data in Yunnan province were used, and with the application of RS and GIS technique, the author explained the land use actuality in 2000, analyzed the spatial change characters of land use form 1986 to 2000, and discussed the change of the soil erosion areas, ecological elastic limit and NDVI, and explored the correlation of the land use change and height, slope and social economic development. At the same time, the author also analyzed the diving forces of land use change in Xishuangbanna Thai Prefecture, after analyzed the impact from land use change on the regional ecological environment, then put forward many suggestions for the ecological environment construction.The result show that, the total land cover area is 301379.4km~2 in Longitudinal Range-Gorge Region, firstly, the mostly land use type is 184565.1km~2 woodland, and it account for 61.31%. Secondly, grassland and cultivated land, separately occupy 20.87% and 16.27%. In general, the land-use change isn't obvious from 1986 to 2000, therein, the settlement area and woodland area had the largest change range, the settlement area increased 13.18% in 14 years, the woodland area reduced 1287.69km~2, occupied 0.69%, the rest of land use types had some extent increase.From 1986, the soil erosion has been some alleviated in Longitudinal Range-Gorge Region, the area of not less than middle degree has decreased ,but the slight degree has increased, so the soil erosion still is the important ecological environment. In addition, the land use change also caused the small range decrease in the ecological flexibility, obvious decrease of NDVI, reducing biodiversity, decreasing soil content and the change of water quantity and quality.The land-use change in Longitudinal Range-Gorge Region largely occurred in that area where lower contour, slope between 15~0 ～25~0 , population density and economy density obviously change. The analysis on the driving forces of land use change in Xishuangbanna Thai Prefecture has been carried out by gray correlation analysis, the result showed that population density was the largest driving force on the cultivated land change, annual average temperature was the obvious driving force on woodland and grassland, Grain Yield was the maximal driving force on garden ploto In conclusion, the change of land use in study region is interacted by natural and social-economical factors.