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以通用土壤侵蚀方程(Universal soil loss equation,USLE)为理论基础,根据研究区实际情况建立了山地城市复杂地形条件下的土壤侵蚀敏感性评价指标体系,对重庆市2000,2005,2010年的土壤侵蚀敏感性进行评价,通过对比分析土壤侵蚀敏感性评价结果与水土流失面积以验证评价结果的精确性和科学性,并对土壤侵蚀敏感性各强度类型之间时空变化来源与去向及其与下垫面要素之间的关系进行了研究。结果表明:土壤侵蚀敏感性面积与水土流失面积总体一致;重庆市2000—2010年水土流失面积和土壤侵蚀敏感区面积分别减少了20 676.10,1 995.89km2,水土流失极强度和土壤侵蚀极敏感区面积增幅分别为63.08%,59.1%,且土壤侵蚀极敏感区域并不一定发生极强程度的水土流失;研究区土壤侵蚀敏感性降级地区主要分布于长江沿岸地区,土壤侵蚀敏感区主要分布在东南部和东北部山区,其时空分布格局与降雨侵蚀力高度一致;未利用地的土壤侵蚀潜在危险指数(Index of soil erosion potential danger,SEPDI)最大,其次是草地、林地、耕地、湿地、人工表面,总体上SEPDI值随着海拔和坡度呈先升高后降低的趋势。10年间,局部区域土壤侵蚀敏感性恶化趋势比较明显,但研究区土壤侵蚀整体情况有所改善,水土保持工作取得了初步成效。
According to the Universal Soil Loss Equation (USLE) theory, the evaluation index system of soil erosion sensitivity under the complex terrain of mountainous cities was established according to the actual situation of the study area. Soil erosion of soil in Chongqing in 2000, 2005 and 2010 The sensitivity and sensitivity to erosion were evaluated. The results of soil erosion sensitivity assessment and soil erosion were contrasted to verify the accuracy and scientificity of the evaluation results. The spatial and temporal variations of the intensity of soil erosion sensitivity between source and destination, The relationship between the surface elements has been studied. The results showed that the area of soil erosion sensitivity was consistent with that of soil erosion. The areas of soil erosion and soil erosion in Chongqing from 2000 to 2010 decreased by 20 676.10 and 1 995.89 km 2, respectively. The soil erosion intensity and soil erosion were extremely sensitive The area increase of the area is 63.08% and 59.1%, respectively, and extremely soil erosion is not necessarily occurred in the most sensitive area. The degraded area of the soil erosion sensitivity in the study area mainly distributes along the Yangtze River. The sensitive area of soil erosion mainly distributes in the The distribution pattern of temporal and spatial distribution of southeastern and northeastern regions is highly consistent with rainfall erosivity; the index of soil erosion potential danger (SEPDI) of unused land is the largest, followed by grassland, woodland, arable land, wetland, artificial On the whole, SEPDI value tends to increase first and then decrease with altitude and slope. In 10 years, the trend of soil erosion sensitivity in some areas is obvious, but the overall situation of soil erosion in the study area has been improved, and initial achievements have been made in soil and water conservation.