Land Use/Land Cover Change and Soil Erosion Impact of Karst Area In Guanling County, Guizhou Province

There is a very serious ecology degradation caused by overuse of land in the Karst area, which is one of the main ecology fragile in southwest of China. This article focuses on a local site—Guanling County, Guizhou province —as a background, and land use/ land cover change as well as its ecology environment impact of the past 12 years in that area is fully researched based on 1987 and 1999 TM images and other relative data. There are some conclusions below: ① Land use has been changed dynamically and obviously, indicated by LUDC (Land Use Dynamic Change) index, which is 1.36% per year; ② The dynamic changes of dry land and grass land are main forms. The dynamic change of reclaimed and abandoned dry land is wilder than that of static change of increased dry land drastically; ③ Land use condition in mountain area is effectively evaluated by the LB (Land Center) index created by the author; ④ The ratio of bare soil is decreased, while the ratios of vegetation cover and naked rock are increased. Besides, the decrease of bare soil is caused partly by the plantation and the soil loss, the latter can make the bare soil turn into naked rock; ⑤ The staggering soil loss contributes the desertification from 22.50% to 26.58%, especially in the dry land where there is a fastest development; ⑥The antierosion life of the bare soil isn't longer than 45.5a by the erosion velocity during 1987-1999 and all the soil will be corroded completely in 86.5a.