基于遥感技术的三峡库区土壤侵蚀量评估及影响因子分析

摘要

基于遥感和地理信息系统技术,利用修正通用土壤流失方程对三峡库区的土壤侵蚀进行定量评估,并进一步分别利用MODIS、TRMM遥感数据对其变化影响的主要因子植被覆盖和降雨侵蚀力变化进行了分析.结果表明:2005年土壤侵蚀总量为11 979.19×104t,平均土壤侵蚀模数为2 087 t/(km2·a),与2000年土壤侵蚀模数2 381 t/(km2·a)相比,减少了294 t/(km2·a).库区东部长江两岸大部分地区植被出现增长趋势,位于研究区边缘附近植被变化不明显;库区降雨侵蚀力总体呈增加趋势,同时降雨侵蚀力年际变化存在较明显的空间差异性.%Based on remote sensing (RS) and geographic information system (GIS), this paper employed the revised universal soil loss equation (RUSLE) to assess quantitatively the soil erosion amount in Three Gorges Reservoir Area. Furthermore, we applied the MODIS and TEMM datasets to analyze the most primary factors, which affected the erosion results in short period, the vegetation coverage and rainfall erosivity. The results were as follows:1 ) the total amount of soil erosion in this area was 11 979.19 × 104 t in 2005, and the average annual modulus of soil erosion was 2 087 t/ (km2 · a) in 2005 reduced by 294 t/(km2 · a) compared with the 2 381 t/(km2 · a)in 2000; 2) for the great proportion in east region and the beach of Yangtze river, the vegetation coverage increased, but the edge of reservoir area was non-significant; 3 ) on the whole, the rainfall erosivity had being increased, and the spatial characteristics of annual rainfall erosivity was very obvious.