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岷江上游属于我国西南山区典型的脆弱生态系统,土壤侵蚀敏感性评价对保护山区生态环境和维护生态安全具有重要意义。利用GIS和RS技术,采用通用土壤侵蚀方程(RUSLE)计算土壤侵蚀敏感性综合指数,综合评价和分析了1995、2000、2005、2010、2014年岷江上游土壤侵蚀敏感性,并分析了汶川地震和人类干扰对土壤侵蚀敏感性的动态影响。结果表明:1)岷江上游土壤侵蚀敏感性以轻度敏感和中度敏感为主,高度敏感和极敏感区域主要分布于岷江上游的干旱河谷区和高山裸土区。1995-2014年土壤侵蚀敏感性整体上较稳定,变异系数平均值为0.05,但土壤侵蚀敏感性综合指数总体呈下降趋势;2)汶川地震使地震烈度较高区域的土壤侵蚀敏感性增强,到2014年,较高敏感性等级的面积变化比例减小,生态恢复明显;3)由人为干扰引起的土地利用变化使土壤侵蚀敏感性增强,环保工程引起的土地利用变化使敏感性降低。
The upper reaches of the Minjiang River belong to typical fragile ecosystems in mountainous areas of southwestern China. Evaluation of soil erosion sensitivity is of great significance for protecting the ecological environment in mountainous areas and maintaining ecological security. Using GIS and RS techniques, the general soil erosion equation (RUSLE) was used to calculate the comprehensive index of soil erosion sensitivity, and the soil erosion sensitivity of the upper reaches of Minjiang River in 1995, 2000, 2005, 2010 and 2014 were comprehensively evaluated and analyzed. The Wenchuan earthquake and Dynamic Impact of Human Disturbance on Soil Erosion Sensitivity. The results showed that: 1) The sensitivity of soil erosion to the upper reaches of Minjiang River was mildly sensitive and moderately sensitive, while the highly sensitive and extremely sensitive areas were mainly distributed in the arid valley and the alpine bare soil in the upper reaches of Minjiang River. The sensitivity to soil erosion was generally stable from 1995 to 2014, with an average coefficient of variation of 0.05, but the overall index of soil erosion sensitivity was generally declining. 2) The Wenchuan earthquake enhanced soil erosion sensitivity in areas with high seismic intensity In 2014, the proportion of area change with higher sensitivity level decreased, and the ecological restoration was obvious. 3) The change of land use caused by human disturbance increased the sensitivity of soil erosion and the change of land use caused by environmental protection project reduced the sensitivity.