坡度对坡面侵蚀产沙响应的研究

Response of Slope to Slope Erosion and Sediment Yield

坡度是影响坡面土壤侵蚀的重要因素，在一定条件下，坡面土壤侵蚀随着坡度的增大而增加，但存在一个临界坡度，当超过这个坡度后，坡面土壤侵蚀量反而随着坡度的增大而减少。国内多数学者认为这个临界坡度介于25°～29°之间，这对我国25°以下坡耕地水土保持措施的配置以及超过25°坡耕地退耕还林还草计划的实施具有一定的理论指导意义。在坡面上不同坡度范围内配置合适的水土保持措施可以削弱坡度对坡面土壤侵蚀强度的影响，即在缓坡上实施保护性耕作措施，在25°以下坡耕地合理布设水平梯田及植物篱，25°以上的坡耕地实行退耕还林还草，可以有效地控制坡面土壤侵蚀的发生，促进坡耕地的可持续利用和改良。

Slope is an important affecting factor for slope soil erosion.Under a certain condition,slope soil erosion increases along with the increase of slope.But,there is a critical slope.When it is exceeded,the slope soil erosion will decrease along with the increase of slope.The majority domestic scholars deem that the critical slope is 25°~ 29°,which has guiding significance on theory for layout of soil and water conservation measures for <25°sloped land and the implementation of conversion of cropland to forest and grassland on >25°sloped land in China.The suitable soil and water conservation measures for different slopes can reduce the influence of slope to the intensity of slope soil erosion,i.e.,implementation protective farming measures on gentle slope,rationally planning leveled terraced and hedgerows on >25° sloped land,conversion of cropland to forest and grassland on >25° sloped land can effectively control soil erosion of slopes and promote the sustainable utilization and improvement of sloped land.