Study on Hydraulic Soil-Erosion with Remote Sensing Information for Jiangxi Province

Rich of quaternary red soil with sticky clay,low water permeability and abundant precipitation caused soil erosion extensive in Jiangxi Province.USLE have been used in evaluating soil erosion for several decades with a multiplication formula by 5 parameters characterizing annual erosion power of precipitation,annual vegetation factor,topography,measure of land management and Soil erodibility respectively.Considering that most of precipitation happened during from May to August in Jiangxi Province and the growth of the vegetation show seasonal temporal pattern,improving USLE with a monthly model was attempted for Jiangxi Province with the monthly EVI composited from the 8-day MODIS EVI product in 2005.Results showed that:(1)Soil erosion is still serious in Jiangxi Province,serious erosion was widely happened over the upper and middle reaches of Ganjiang River,Huhe River,Xinjiang River,Raohe River and Xiuhe River and the amount of soil erosion is about 1.346×109 ton p.a.;(2)about 21.4% of the area in Jiangxi Province is in soil erosion.The region with a area of 14906km2 is in over-moderate soil erosion,in which the area of moderate soil erosion is 8374km2,of intensive soil erosion is 3089km2,of extreme intensive erosion is km2 and of drastic intensive erosion is 1356km2;(3)though the Monthly-USLE is more reasonable because of the seasonality of precipitation and vegetation growth,the soil erosion happened in Jiangxi Province from Monthly-USLE is not similar with that from Yearly-USLE.The soil loss estimated by Monthly-USLE is smaller than that by Yearly-USLE.