长江三峡库区土地覆被类型对坡面产沙的影响

 为探讨长江上游三峡库区的产沙时空变异与环境变化的关系,选择重庆四面山为试验地点,分析不同土地覆被类型对坡面产沙的影响。针对当地不同地类,设置30个小型坡面土壤流失观测区,分析不同土地覆被坡面的产沙差异。结果表明,当地坡面流失的泥沙主要来源于坡耕地和裸地,25°以上陡坡耕地侵蚀的泥沙量,约占坡面产沙总量的50%。土地覆被状况对于泥沙的产生有重要影响,同等条件下,若林地土地覆被率达到70%～80%,则能够减少71.05%～95.58%的泥沙产生量。

Effects of land-cover types on sediment yield in the Three-Gorge Region of Yangtze River

The effects of land-cover change on sediment yield in Simian Mountain were studied to probe into temporal and spatial variation rule of sediment yield and the relation to environment change in the Three-Gorge Region of Yangtze River.Thirty soil erosion plots were located.The influence of different vegetation types on sediment yield was studied by analyzing process of rainfall,and soil erosion on different degrees slopes under different land-use condition.Results showed that sediment yielded from slope chiefly come from arable land and bare land located at slope,and the quantity of sediment yielded from arable land located at the slope above 25°accounted for about 50% of the total sediment yielded from slope.Land cover types had significant effects on sediment yield of slope.At the same time,the amount of sediment could be decreased 71.05%-95.58% if the forest cover rate reached 70%-80%.