三峡库区不同土地利用背景下的土壤侵蚀时空变化及其分布规律

发布时间：2018-09-01 12:56

【摘要】：土壤侵蚀是影响三峡库区土壤养分流失、河道淤积等一系列生态环境问题的重要原因,本文基于GIS技术,采用通用土壤流失方程,对三峡库区1990、1995、2000、2005和2010年的土壤侵蚀进行计算,并对研究区1990—2010年不同土地利用背景下土壤侵蚀强度的时空变化和分布规律进行定量分析。结果表明:1990—2010年,三峡库区平均土壤侵蚀模数与土壤侵蚀量呈减少的趋势,多年平均土壤侵蚀量为18 356.450 7万t,属于中度侵蚀;从空间上看,研究区微度、轻度侵蚀等级分布面积最广。在同一年分内,6种不同土地利用下土壤侵蚀模数依次为:旱地草地林地未利用地水田建设用地;不同土地利用下的土壤侵蚀差异显著,不同土地利用对土壤侵蚀的贡献率相差很大;各土地利用类型中,微度侵蚀的面积逐渐增加,中度侵蚀及以上侵蚀等级的侵蚀面积,都不同程度的向低等级转移;随着退耕还林还草及大量农村劳动力的外出,库区的土壤侵蚀总体上呈现转好的趋势,但是局部地区的治理工作仍需加强。
[Abstract]:Soil erosion is one of the most important factors affecting soil nutrient loss and river siltation in the three Gorges Reservoir area. Based on the GIS technique and the general soil erosion equation, the soil erosion in the three Gorges Reservoir area in 2005 and 2010 is calculated. The temporal and spatial variation and distribution of soil erosion intensity under different land use background in the study area from 1990 to 2010 were analyzed quantitatively. The results show that the average soil erosion modulus and soil erosion amount in the three Gorges Reservoir area decreased from 1990 to 2010, and the average soil erosion volume was 18 3.564507 million tons per year, which belongs to moderate erosion. Mild erosion grade is the most widely distributed area. In the same year, the modulus of soil erosion under 6 different land uses was as follows: dry land, grassland, forest land, paddy field construction land, and soil erosion under different land use were significantly different. The contribution rate of different land use to soil erosion is very different, in each land use type, the area of micro-degree erosion increases gradually, and the erosion area of moderate erosion and above erosion grade transfers to low grade in different degree. With the conversion of cropland to forest and grassland and the exodus of a large number of rural labor force, the soil erosion in the reservoir area shows a trend of improvement in general, but the management work in some areas still needs to be strengthened.
【作者单位】：重庆师范大学地理与旅游学院;三峡库区地表过程与环境遥感重庆市重点实验室;
【基金】：国家水体污染控制与治理科技重大专项课题“三峡库区及上游流域农村面源污染控制技术与工程示范”(2012ZX07104-003)
【分类号】：S157.1

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