Soil Erosion Change And Prediction In Hubei Section Of Three Gorges Reservoir Area Based On CSLE Model

Water and soil resources are not only the fundamental conditions for human survival and development,but also the necessary basic resources for the sustainable development of economy,society and ecological environment.Soil erosion has huge risk potentially,which leads to increasingly severe damage about global environmental change.Nowadays,degraded soils are the most common and constant environmental issues people ever faced.Soil erosion and conservation in Three Gorges Reservoir area is a great measure related to ecological environment improvement and the long-term safe operation of the Three Gorges Project.Thus studying the process of soil erosion is the key to solving local water and soil problems.The study relies on the Hubei area of the Three Gorges Reservoir.Combining CSLE model with GIS,the factors affecting soil erosion and the amount of soil erosion are obtained and calculated,and then can classify three periods of 2005,2010 and 2015 about soil erosion intensity.Simultaneously,study current situation of land use in such area at the same time as well as analysis the relationship about the transformation of land use and growth and decline of soil erosion.Along with three periods of soil erosion's data,using CA-Markov model,simulate and predict soil erosion in 2020 in IDRISI,ultimately propose relative measures and advice according to the predicted consequences.The main conclusions of this paper are as follows:(1)From 2005 to 2015,soil erosion intensity was mainly slight erosion(61.00%~75.01%)and mild erosion(13.32%~16.68%),with increased erosion taking 20.17%.The proportion of moderate and above erosion areas increased first and then decreased,but the decrease of severe erosion was not significant.Generally speaking,the soil erosion intensity level in the study area tends to migrate to lower erosion intensity level.(2)In research area,forestry was the widest during three periods,next were farmland and meadow.Generally,from 2010 to 2015,the migrated area around any type of land use took up 0.80%of total land area,which was apparently heightened compared to 2005 to 2010.In the same time,the variety of land use was reflected in the transformation from forestry and farmland to construction sites.The minor varied range of land use illustrated quicken urbanization rate compared to 2005 to 2010 obviously.The field area increased at 13.65 km~2,in order to develop economy vigorously,they constantly imported adaptive local fruit trees such as oranges.(3)By overlying variation diagram of land use and soil erosion,it reaches statistics and analysis about the effects of transformation between different land use types on the growth and decline of soil erosion.The result shows that it is similar with changed situation of soil erosion intensity area in different land use types from 2005 to 2010 and2010 to 2015.There exists relation between land use variety and soil erosion intensity variety to some extent.(4)Soil erosion forecasting results show that the soil erosion intensity is expected in 2020 than in 2015,the most moderate and strong erosion into micro and mild erosion,there are 82.86 km~2,moderate above erosion area is reduced,and visible effect of soil and water conservation,should continue to increase the intensity of soil and water conservation,prediction results of soil and water conservation planning and land arrangement work.