Study On Characteristics Of Soil Erosion And Its Control Measures Of Large Hydropower Stations In The Ya-long River Basin

In this study,the status of soil and water loss,soil and water conservation,Layout of control measures in Jin-ping II hydropower station and Jiang-bianhydropower station located in Ya-long River were studied by means of field surveysand statistical analysis,and based on the characteristics of the Ya-long River basin,theconcrete measures of soil and water conservation for different control zoning of hydropower projects of Ya-long River Station were designed.The main conclusions are as follows:(1)The water erosion is the main erosion type in Ya-long River hydropower station construction project,and there are also some gravity erosion.Deep valley rainfall and shallow soil,soil anti erosion ability,poor vegetation cover conditions and other natural factors and human factors such as engineering construction activities are the main factors of soil erosion.(2)The surface disturbance area of the Jin-ping II hydropower station and the Jiang-bian hydropower station is the largest during the preparation period,indicating the preparatory period is the main period of surface disturbance period of Ya-long River hydropower station construction project.The water and soil loss of Jin-ping ?hydropower station and Jiang-bian hydropower station is the largest in the preparation period and construction period,indicating preparation period and construction period are the main periods of soil erosion in Ya-long River basin hydropower project construction station.(3)The abandoned slag yard area is the main division of soil and water loss,and it should be protected and governed in the Layout and design of soil and water conservation measures for the Ya-long River Hydropower Station Construction Project.In addition,the main area of construction activities and the main source of earthwork such as the construction of the road area,construction temporary facilities area,hub project area should also be the main area of soil erosion prevention andcontrol.(3)After the completion of the construction of the Jin-ping II hydropower station and the Jiang-bian hydropower station,the overall implementation of its water and soil conservation measures is in good condition.The total control degree of soil erosion were 98.34%and 98.81%respectively,the control ratio of soil erosion were 1.30 and 1.19 respectively,the rate of slag control was 97,86%and 97.76%respectively,the rate of remediation of disturbance land were 98.94%and 98.50%respectively,and the coefficient of vegetation restoration was 98.05%and 96.74 respectively,the forest vegetation coverage rate of 42.12%and 49.19 respectively.All the soil and water conservation effects reach the standard of prevention and control,showed that the soil and water conservation measures of Jin-ping ? hydropower station and Jiang-bian hydropower station could control the soil erosion caused by the station in the Ya-long River basin hydropower construction project effectively,and it could provide reference for the prevention and control of soil erosion of hydropower station construction project in Ya-long River Basin.(4)Summary the prevention measures of soil and water conservation of the Jin-ping ? hydropower station and Jiang-bian hydropower station layout showed that the prevention measures need to pay attention to the slope protection,drainage system,slag protection,and the plant measures should also be followed up in time.According to the characteristics of soil erosion and the natural conditions in the Ya-long River Basin,and referencing to the control layout of soil and water conservation measures of the Jin-ping ? hydropower station and the Jiang-bian hydropower station in the Ya-long River Basin,the specific soil and water conservation measures were designed for different control zones to provide reference for the prevention and control of soil erosion in construction project of hydropower station in Ya-long River basin.