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选以丹江口库区及上游治理的38条小流域为研究对象,以2007与2010年ALOS遥感影像为信息源,借助遥感和地理信息系统技术,解译出与土壤侵蚀密切相关的土地利用类型、植被覆盖度,同时根据数字高程模型(DEM)提取坡度,将这3个因子在Arc GIS中进行叠加和统计分析,生成每条小流域的土壤侵蚀强度分级图并统计出各等级所占的面积。把各条小流域分析结果汇总,利用2007(治理前)、2010年(治理后)坡度、土地利用、植被覆盖度、土壤侵蚀的汇总结果来评价水土流失治理工程的总体成效。结果表明:治理区地形以陡坡、急坡、险坡为主,三者占治理土地总面积的74.52%;经过三年治理,林地、园地、交通用地分别增加了326.05 km2、0.54 km2和6.32 km2,耕地、草灌、城镇工矿用地分别减少了113.44 km2、206.65 km2和3.47 km2;低覆盖度、中低覆盖度、中等覆盖度、中高覆盖度林草面积均在减少,高覆盖度林草面积大幅增加,增加了451.88 km2;在各土壤侵蚀强度等级中,中等强度侵蚀减幅最大,减少了173.60 km2,2007~2010年水土流失总面积减少了339.24 km2。
In this paper, we selected 38 small watersheds managed by Danjiangkou reservoir area and the upper reaches as the research object, and took the ALOS remote sensing images of 2007 and 2010 as the information sources. With the aid of remote sensing and geographic information system technology, the land use types, Vegetation coverage, and according to the digital elevation model (DEM) to extract the slope, these three factors were superimposed and statistically analyzed in ArcGIS to generate the soil erosion intensity map of each small watershed and calculate the area occupied by each level . The results of the various watershed analyzes are summarized and the overall results of the soil and water erosion control project are evaluated using the combined results of 2007 (before treatment), 2010 (after treatment), slope land use, vegetation cover and soil erosion. The results showed that the terrain of the control area was mainly steep slope, steep slope and dangerous slope, accounting for 74.52% of the total land area. After three years of treatment, the area of forest land, garden and traffic increased by 326.05 km2, 0.54 km2 and 6.32 km2, respectively , And arable land, irrigated grassland and urban industrial and mining land decreased by 113.44 km2, 206.65 km2 and 3.47 km2, respectively; the area of forest and grass with low, medium and medium-high coverage decreased while the area with high coverage of forest and grass Which increased by 451.88 km2. Among all the soil erosion intensity grades, the decrease of middle-intensity erosion was the largest, with a decrease of 173.60 km2. The total area of soil erosion from 2007 to 2010 decreased by 339.24 km2.