Monitoring And Evaluation Of Soil And Water Loss About Wind Farm In Piedmont Alluvial Plain

Based on the theory and method of soil and water loss monitoring,through the field investigation and monitoring research for 12 months(2018.01-2018.12)during the construction period of the project,according to the monitoring results,the soil and water loss situation in the project area is analyzed,and the main factors leading to soil and water loss and their influence degree in the construction process of the project area are analyzed.Two different monitoring methods were used to monitor soil erosion in the project area.The results were analyzed through 12-month monitoring.The main results are as follows:During the 12-month monitoring period,according to the different disturbance conditions of six zones in the project area(tower base area,tower base construction area,cable tunnel area,stretching field area,spanning construction area and construction accessory area),runoff plot method and simple slope surface measurement method were used to monitor sediment volume.Runoff plot method is based on the sediment entrained by rainwater runoff,and then the monthly sediment amount is calculated.The sediment amount before and after disturbance in each plot is sorted out,and the corresponding soil erosion modulus is calculated.Simple slope measurement method calculates the amount of erosion by measuring the length,width,depth and number of erosion gullies,thus determining the modulus of soil erosion in the project area.The disturbed surface area of the project is 8.69 hm2,and the total amount of excavation and filling is 60.5 million m3.Before disturbance,the soil erosion modulus of each zone was 434t/(km2a),376t/(km2a),595t/(km2a),451t/(km2a)in cable tunnel area,770t/(km2a)across construction area,582t/(km2a)in construction sidewalk area.After disturbance,there are 2816t/(km2a)in tower base area,2512t/(km2a)in tower base construction area,3026t/(km2a)in cable tunnel area,2343t/(km2a)in traction area,2003t/(km2a)across construction area,2615t/(km2a)in construction sidewalk.According to the disturbance time,the total amount of soil and water loss during the construction period can be calculated to be 52.23 t,and the additional amount of soil and water loss is 42.80 t.The total amount of soil and water loss during natural recovery period is 242.75 t,and the additional amount of soil and water loss is 119.32 t.From the amount of soil erosion,it can be seen that the project construction has brought serious soil erosion and endangered the local environment.