Regional Quantitative Assessment Of Soil Erosion Based On GIS And CSLE Model

The type of soil erosion in Guangxi is hydraulic erosion, and its territory ismainly Karst areas and red soil regions. Both the Karst and red soil are the ecologicalenvironment fragile zone. Furthermore, because of unreasonable land use mode andstrong influence factor, these areas are easily induce soil erosion, leading severe rockydesertification and soil and water loss. Therefore, develop a set of methods ofquantitative assessment of soil erosion to identity the status of soil erosion in Guangxi,and master the distribution, area and intensity have important theoretical and practicalsignificance. In view of this, by using remote sensing and GIS technology, takingCSLE model as the theoretical guidance, explore the CSLE model whether availablein the Karst area and red soil region. The research is supported by the first nationalsurvey of soil and water conservation of Guangxi. And on this basis, establish adatabase of quantitative assessment of soil erosion in Guangxi and the calculation andanalysis platform of soil erosion impact factor. Finally, take Karst area Dahua and redsoil region Cenxi as a example for empirical study. In this paper, the main conclusionsare as follows:1.Design and set up a database of quantitative assessment of soil erosion inGuangxi. Based on remote sensing and GIS technology, design and build a databaseof quantitative assessment of soil erosion in Guangxi. Using GIS, Geodatabase modeland database technology, in accordance with the principle of hierarchicalclassification, establishing database of quantitative assessment of soil erosion inGuangxi, the main data are basic geography, soil erosion impact factors, satelliteimages, weather, soil erosion intensity raster, vector, attributes and documentation.This can be provide the basis data and technical support for calculation of soil erosionfactor, evaluation of soil erosion and ecological construction.2.Based on Chinese Soil Loss Equation(CSLE), integrated use of.Net, Python,ArcPy site package, Python Add-in programming technology and Workflowtechnology. Using raster data analysis, tread surface analysis and geostatistical analysis algorithm, design and develop the calculation and analysis model of therainfall erosion force R, soil erodibility K, slope and length factor LS, biological,engineering and tillage measure of soil and water conservation, vegetation coverageand rocky desertification factor. This model can automate and analysis the soil erosionimpact, and can provide a automation platform for quantitative assessment of soilerosion at a regional scale.3.Based on the established database and analysis platform, taking Dahua andCenxi as an example to carry out the pilot study of regional soil erosion evaluation.According to the actual situation and the status of the study area, the use of differentcalculation methods and formulas to determine Dahua and Cenxi soil erosionquantitative evaluation of each factor value, calculated on the basis of soil erosion inthe study area modulus and accuracy verification, the result indicates that thesimulation result is good. The Dahua and Cenxi soil erosion of total area is amountedto2744.13km2、2710.83km2in2010, its annual average soil erosion is1059.96t/(km2.a)、1106.23t/(km2.a). Reveals the DaHua and CenXi relationshipbetween soil erosion and major influence factors.(1) the higher elevation in the studyarea, soil erosion area is smaller, decrease relations;(2) in general, each more than15°area in the study area is the key of the prevention and control of soil erosion, shouldstrengthen the prevention and control of soil erosion of the region;(3) DaHuacompared with CenXi, DaHua belongs to typical cause Karst mountainous, soilerosion characteristics of different land use types and the Karst area has biggerdifference;(4) DaHua and CenXi soil erosion in the main soil types of lime soil (rock)respectively, latosolic red;(5) Soil erosion characteristics of different vegetationcoverage Dahua County has significant differences with Cenxi, vegetation cover50to60percent and60to70percent is focused on the type of soil erosion intensitydistribution, erosion intensity in the50to70percent of the vegetation coveragethresholds exist, erosion intensity and non-karst areas which increases soil vegetationcover decreases the characteristics of the opposite, forming a unique karst vegetationcover large areas but soil erosion intensity characteristics.