| Soil is the basis of human development and survival, and the soil erosion is the important factor to cause land degradation, destruction of land resources and a series of environmental problems, all of these restrict the process of human sustainable development and ecological civilization construction. Therefore, monitoring and prediction of soil erosion is essential,and the treatment of soil erosion is also urgent.The rapid development of geographic information system and remote sensing technology provides a strong technical support for real-time monitoring of soil erosion and intuitive observation of spatial pattern.The Panxi area located in Sichuan province, where the geological structure is complex and heavy rain. Based on the RUSLE model, the paper aims to calculate the amount of the soil erosion and the soil erosion modulus, then, analyze spatial distribution characteristics of soil erosion intensity with the technology of remote sensing and GIS. On that basis, using the factor detector and interaction detector of geographical detectors analysis the relationship between amount of the soil erosion and the various factors. The main conclusions are as follows:(1) The average soil erosion modulus of the study area was equaled to 26.96 t · h-2 · a-1 which belonged to the mildly erosion. It is larger than that allowed soil erosion modulus which was 5 t · hm2 · a-1 made by the national regulations in southwest region. The mildly erosion was the mainly degree of the soil erosion in the study area, which occupy 37.37% of the soil erosion area. The slightly erosion and moderate erosion occupy 20.43% and 20.39% of the soil erosion area which mainly distributed in the middle and lower reaches of the river which is more extensive alluvial plain area and the valley area of Anning River, Yalong River and Jinsha River regions. Sum of area percentage is 21.81% of intensive erosion, extremely intensive erosion, extremely intensive erosion, severe erosion, which distributed mainly in area with north-south orientation of large slope and low vegetation coverage in central area of Panxi area.(2) The change trend of soil erosion intensity present reduced in size on different elevation. Soil erosion intensity showed a trend of wave shape change on different slpoe. With the change of slope, the same intensity of soil erosion area has been changed. But with the increase of vegetation coverage, the greater of the soil erosion intensity the proportion is falling. Under the condition of different land use types and soil erosion intensity is different too. The Paddy field, residential areas, construction land, urban land, lakes, canals, reservoirs, bare land, unused land, beaches which belonged to the mildly erosion; and the dry land is mainly composed of mildly erosion and slightly erosion; With the increase of altitude and gradient, human activity is less and less. The soil proportion of forestland,high coverage grassland,shrub land, open woodland, moderate coverage grassland, low coverage grassland and other varieties of woodland, which the proportion of the mildly erosion,moderate erosion, intensive erosion is greater than the other land use types.(3 ) The factor detector of geographical detectors reveals that the relative size and explanatory power of different geographical factor layers to the amounts of soil erosion is: slope (0.9578) > rainstorm frequency (0.7534) > catchment basin area(0.4616) > land-use types (0.3127) > soil type(0.1499) > River network level(0.013) > Distance from the river (0.066) > Distance from the catchment point(0.0025) . And the interaction detector reveals the interactions between various factors is greater than the single factor's influence on the soil erosion. |
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