Study on the Characteristics of Runoff and Sediment Production on Slope Land of Plateau Wetland Napa Lake

In order to study soil erosion and water loss on the slope land around plateau wetland Napa lake,runoff plots were employed,and runoff and sediment production caused by rainfall on different types of slope land were collected.Results showed that natural secondary forest and grass help to protect soil from erosion.The runoff of farmland was 3.6 and 2.7 times,and the soil loss 13.8 and 6.7 times as much as those from natural secondary forest and grass land respectively.Young Picea asperata plantation could decrease runoff and soil loss amounts by 42.2% and 82.1% compared to slope farmland,respectively.Soil loss increase linearly with the runoff amounts on different types of slope land,and a significant correlation was found on slope farmland.When planting shelter forests to prevent soil and water loss,single tree species should be avoided and rational and spatial combination of tree-shrub-grass should be recommended.