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土壤侵蚀是造成东北林草交错区生态脆弱的重要原因。论文应用GIS技术,综合降水、地形、土壤可蚀性、植被覆盖等因子,分析和评价了1990—2005年研究区土壤侵蚀敏感性时空变化过程,并通过叠加排序方法定量识别关键因子。结果表明:研究区以中度敏感为主,其次是轻度和高度敏感;中度敏感地区以大兴安岭山地为主,轻度敏感地区分布在东、西部平原地区,高度敏感地区主要分布在燕山山地和大兴安岭南部山地的林草交错区;从时间变化过程看,轻度、中度敏感地区面积增加,高度敏感地区面积减少,生态环境状况总体好转;地形起伏度和植被覆盖作为研究区土壤侵蚀关键因子,起主导作用。
Soil erosion is an important reason for the ecological fragility in the crisscross region of forest and grass in Northeast China. In this paper, the spatial and temporal changes of soil erosion sensitivity in the study area from 1990 to 2005 were analyzed and evaluated based on the integrated precipitation, topography, soil erodibility and vegetation cover, and the key factors were quantitatively identified by the additive ranking method. The results showed that the study area was mainly moderately sensitive, followed by the mild and highly sensitive areas. The moderately sensitive areas were mainly the Greater Xing’an Mountains and the mildly sensitive areas were located in the eastern and western plains. The highly sensitive areas were mainly distributed in the Yanshan Mountains And the forest-grass mixed area in the mountainous area of southern Daxinganling. According to the time course, the area of mild and moderately sensitive areas increased, the area of highly sensitive areas decreased, and the ecological and environmental conditions were generally improved. The topographic relief and vegetation coverage were the key factors of soil erosion in the study area Factors, play a leading role.