Study on the Response of Soil Conservation under Regional LUCC——A Case Study in the Yulin Region

Based on the technologies of 3S(RS,GPS and GIS) and universal soil loss equation(USLE),in this paper the values of soil erosion and soil conservation perunit area in different ecosystems in the Yunlin region in 1987,1999 and 2002 are estimated and was integrated.The results show that the soil conservation per unit area of all the ecosystems was in an order of garden plots woodlands shrubberies grasslands.The interannual difference of precipitation and the spatial difference of landforms were the dominant factors resulting in the interannual change and spatial difference of soil conservation per unit area in all the ecosystems.The total quantities of soil conservation per unit area in all the ecosystems in the Yulin region in 1987,1999 and 2002 were 2.22×108 t,1.96×108 t and 2.07×108 t respectively.During the whole study period from 1987 to 2002,the ratio of soil conservation per unit area in all the ecosystems in the Yulin region was continuously increased,but there was some spatial difference.that means the total quantities and efficiencies of soil conservation of all the ecosystems in 6 counties in the south in 1987 and 1999 were significantly higher than that in 6 counties in the north,but they were slightly higher in 6 counties in the north than that in 6 counties in the south in 2002.During the whole study period,the efficiencies of soil conservation in all the ecosystems in 6 counties in the north were significantly increased,But not in 6 counties in the south and even slightly decreased in 2002.Comparatively,there was more natural restriction in making further soil conservation efficiency in 6 counties in the south than that in 6 counties in the north.