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为了解岷江源头区森林经过变迁对土壤侵蚀的影响,利用遥感和GIS技术分析了岷江源头区的森林景观动态(1974～2002年),应用USLE模型计算该区域同时期的土壤侵蚀变化。近30年来,随着森林景观面积的持续增加,土壤侵蚀量逐渐减少,各景观类型的散布指数也随着土壤侵蚀量的减少而增加。各不同的森林景观控制土壤侵蚀的能力存在差异,针叶林最优,阔叶林次之,针阔混交林最差。森林景观破碎度随土壤侵蚀的增长而增加,分布在较轻侵蚀区中的景观斑块具有更复杂的形状。
In order to understand the impact of forest change on soil erosion in the source region of Minjiang River, the landscape dynamics of the source region of the Minjiang River from 1974 to 2002 were analyzed by remote sensing and GIS technology. The soil erosion of the region was calculated by the USLE model. In the recent 30 years, with the continuous increase of forest landscape area, the amount of soil erosion gradually decreased and the distribution index of various landscape types also increased with the decrease of soil erosion. Different forest landscapes have different ability to control soil erosion. Coniferous forest is the best, followed by broadleaf forest and coniferous and broad-leaved mixed forest. The degree of forest landscape fragmentation increases with the increase of soil erosion, and the landscape patches distributed in the less eroded area have a more complex shape.