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以云南洱海流域为研究对象,根据已有的流域DEM、Landsat-5 TM卫星数据和当地降雨、土壤类型等资料,在GIS、Erdas及ArcView软件支持下,应用USLE模型计算了洱海流域1989—2006年土壤侵蚀变化并对其土壤侵蚀特征进行了分析。研究表明:轻度侵蚀由占总面积的13.89%下降到6.47%,中度侵蚀由占总面积的6.49%增至14.04%,微度和极强烈侵蚀小幅增加,强烈和剧烈侵蚀小幅减少;微度、轻度、强烈和剧烈侵蚀多转化为中度侵蚀,面积分别为22.20、123.539、.68和22.91 km2,中度侵蚀多转化为微度侵蚀,极强烈侵蚀多转化为剧烈侵蚀;18年来,土壤侵蚀强度与面积年均变化率以中度侵蚀最大(6.46%),轻度、强烈、剧烈和微度侵蚀年均变化率分别为-2.97%、-0.11%、-0.10%、0.056%,极强烈侵蚀年均变化率最小(0.020%)。
Taking the Erhai Lake in Yunnan as a research object and using the data of the existing DEM, Landsat-5 TM satellite data, local rainfall and soil types, and GIS, Erdas and ArcView softwares, the USLE model was used to calculate the spatial distribution of the Erhai Lake Basin in 1989-2006 Annual soil erosion changes and their soil erosion characteristics were analyzed. The results show that slight erosion decreased from 13.89% of the total area to 6.47%, moderate erosion increased from 6.49% to 14.04% of the total area, micro and extremely intense erosion increased slightly, intense and severe erosion decreased slightly. Moderate, severe, and severe erosion. The areas were 22.20,123.539, .68 and 22.91 km2, respectively. Most of the moderate to severe erosion was transformed into micro-erosion, and the most intense erosion changed into severe erosion. In 18 years , And the annual average rate of change of soil erosion intensity and area was moderately eroded (6.46%). The annual average rates of mild, intense, intense and slight erosion were -2.97%, -0.11%, -0.10% and 0.056% , The annual average rate of very strong erosion is the least (0.020%).