长江上游生态系统土壤保持重要性评价及分区

长江上游是我国西部重要的生态屏障,开展该区的生态系统土壤保持重要性评价级及分区将为长江上游生态系统功能保护区规划的制定提供科学依据。在长江上游土壤侵蚀敏感性评价的基础上,结合土壤侵蚀现状,滑坡泥石流的危害,以及土壤侵蚀对河流、水库等洪水调控能力的影响程度,确定土壤保持重要区域,并根据河流泥沙输移能力分布情况以及土壤保持重要性相同等级成片集中分布且地貌类型一致原则,将长江上游生态系统分为土壤保持极重要区、重要区、较重要区、中等重要区、一般重要区总共5个类型区,对科学地开发利用长江上游土地资源有重要的指导意义。

Significance Evaluation and Zoning of Ecosystem Soil Conservation in the Upstream of the Yangtze River

Significance evaluation and zoning of ecosystem soil conservation will provide scientific basis for the planning of ecosystem protection regions in the upstream of Yangtze River,  the ecological shelter of west China. The following factors were selected as the evaluation indexes: rainfall erosivity, soil erodibility, topographic relief degree, and vegetation cover. Based on the sensitivity assessment of soil erosion, and in association with hazards of landslide and debris flow, and impact degree of soil erosion on the flood control capacity of rivers and reservoirs, as well as river sediment transport capacity, and soil conservation significance level and landform consistency, the upstream area of Yangtze River was divided into 5 zones according to the significance levels. This result will be important guidance for the utilization of land resources in the upstream of Yangtze River.