The Study Of Soil Erosion In Dongchuan Region Using RS And GIS

As one of the serious environmental problems in the world, soil erosion has attracted national attention. There are many quantitative analyses on the area for many years at home and abroad. With the improvement on the remote sensing and geographic information systems, both of them was applied to the regional survey on the soil erosion, effectively improve the accuracy and speed of survey.Dongchuan area, because of its natural conditions and long-term mining activities, soil erosion is much more serious. On the base of collecting data related to the geographical area, remote sensing image, soil and other data, the paper extract related information and then obtain the erosion factors. Then, using GIS technology to establish USLE model (USA Soil Loss Equation), synthesize these erosion factors and extract the quantitative information on soil erosion. The research includes:(1) Extract vegetation coverage from remote sensing image. Combining spectral characteristics extracted from remote sensing image with previous research results, and using FCD model to extract NBSI vegetation index in order to estimate vegetation coverage information in the study area. The results show that the FCD model has high precision on vegetation cover information extraction and can reduce the interference of the shadow information.(2) The acquisition method of soil erosion factor. Make use of remote sensing images and terrain data to extract the dominant factors that affecting soil erosion: vegetation cover, land use types, topographic features, reference of the soil distribution and previous research results for the soil erosion factor.(3) Quantitative study on soil erosion. Use USLE soil erosion model to extract soil loss information in the study area. The results show that the USLE-based remote sensing survey has fully theory base and excellent effection on investigation. Meanwhile the paper also analyz the level of soil erosion in the study area and the spatial distribution of soil erosion from the size of the topographical features and the distribution of residents.(4) The relation between soil erosion and factors. Considered from the landscape, soil erosion is mainly distributed in the terrain slope from 7 to 25 between hilly areas, taking into consideration from the vegetation, soil erosion mainly distributed in the vegetation coverage rate below 0.60. In addition, the relationship between the soil erosion and land use / cover relationship was analyzed and the results show that the low vegetation cover and bare land prone to take place soil erosion.(5) According to the distribution and occurrence of soil erosion features in the study area, the paper proposes some corresponding control program.