摘要:基于RS和GIS技术,采用RUSLE模型的月模式,计算岷江上游2000,2005,2010年的土壤侵蚀量,对其时空格局动态变化进行分析,并从坡度、土地利用类型、高程3个方面系统分析土壤侵蚀现状。结果表明:(1)岷江上游土壤侵蚀与地形因子和土地利用方式密切相关,对于岷江上游而言,海拔2 000 m以下和4 000?5 000 m且坡度在25°?45°区域内的稀疏植被、裸土、草原以及旱地是土壤侵蚀的重点防治区。(2)岷江上游2000,2005,2010年的土壤侵蚀模数分别为2 275.38,2 664. 73,3 309.26 t/(km~2 ? a),土壤侵蚀呈现加剧的趋势。(3)退耕还林还草工程的实施使得2005年比2000年的土壤侵蚀量减少9. 27* 10~4 t,汶川地震使得2010年比2005年的土壤侵蚀量增加了33.4* 10~4 t,国家实施的退耕还林还草工程在改善水土保持功能上取到了很大的成效,汶川地震加剧了土壤侵蚀程度。

The combination method of GIS,RS and RUSLE was used to calculate the amount of soil erosion in 2000,2005 and 2010,and the states of soil erosion were studied from three aspects, including slope, land use patterns and elevation. The results showed that : (1) The soil erosion of Minjiang watershed closely related with slope and land-use pattern, and area with intense soil erosion mainly distributed in the region with slope between 25° and 45°, altitude below 2 000 m and between 2 000?3 000 m, as well as land-use patterns of sparse vegetation, bare soil, grassland and dry land. (2)Soil erosion modulus in 2000, 2005 and 2010 were: 2 275. 38,2 664.73,3 309. 26 t/(km~2 ? a),respectively, and showed increasing trend of soil erosion. (3)The amount of soil erosion in 2005 reduced 9. 27X10~4 t than that in 2000 since the implementation of grain for green project, however, the amount of soil erosion in 2010 increased 33. 4* 10~4 t than that in 2005 because of the Wenchuan earthquake. It showed that the grain for green project improved water and soil conservation function and the Wenchuan earthquake exacerbated the degree of soil erosion.