Evaluation of soil erosion risk in Karst regions of Chongqing, China

摘要

Eco-system in karst regions is unstable, and karst-desertificaton induced by soil erosion is an important threat in southwest China. Evaluation of soil erosion is necessary for planning of soil and water conservation for sustainability of land resources and eco-system in those regions. This paper was to estimate risk of soil erosion and understand its spatial distribution in karst regions in Chongqing where are typical area with crisp eco-system in the southwest China. Land use/land cover data was deduced from remote sensing data of TM images of study area in 2000. Soil erodiable K values were estimated from soil texture and' organic matter. The data of erosivity of precipitation, terrain, land use/land cover, soil erodible K values was used in this study with rectified USLE model and grid calculation of ArcGIS9 software to evaluate the soil erosion risk and analyze its spatial distribution in this region. The results showed that the risk of soil erosion was severe in the mass and its spatial difference was obvious due to integrative effect of rainstorms, Soil erodibility, topography, and land use/land cover in karst regions in Chongqing. The distribution of soil erosion risk class was closely related to the terrain, land use/land cover in those Karst regions. The large risk rate happened in areas where the terrain is steeper and the human activities were frequent for the agriculture was intensified. This must be paid more attention to by local government and people to take measures for regional soil and water conservation and sustainable development of eco-environment in karst regions in Chongqing.