Simulation And Control Technology Of Non-point Source Pollution In The Drinking Water Of Tieshan Reservoir Based On RUSLE

Tieshan Reservoir is an important drinking water source in Yueyang City and Yueyang County.It has great significance to protect the water quality of reservoirs and carry out research on non-point source pollution simulation and control in reservoir basins.Based on ARCGIS technology and the modified soil loss equation RUSLE,this paper simulates the soil erosion amount and the soil nitrogen loss pollution load generated by slope soil in the reservoir area,and proposes the returning farmland to forest and returning grassland to forest.The fertilization technology of cultivated land and the rational arrangement of nitrogen and phosphorus pollutant control technologies such as stable ponds.The main results of the study are as follows:(1)By establishing a soil erosion model in the Tieshan Reservoir area,the results show that the soil erosion area in the reservoir area is dominated by light erosion,accounting for 47.54%of the total area,but the erosion amount only accounts for 33.20%of the total erosion;The extreme strength and severe erosion area accounted for 0.45%and 2.01%,respectively,and the erosion amount accounted for 2.64%and 43.38%of the total erosion,respectively.The soil erosion amount contributed the most with the severe erosion.Among them,the extreme intensity and severe area of erosion are mainly grassland,and the small part is cultivated land with steep slope.(2)Through the established soil erosion model in the reservoir area,the concept of sediment transport was introduced,and the nitrogen and phosphorus loads on the slope farmland in the reservoir area were estimated.The adsorption load of nitrogen and phosphorus in the reservoir area was 90.81t and 35.24t,respectively.The overall law of soil-adsorbed nitrogen and phosphorus load is basically similar to the overall law of spatial distribution of soil erosion,mainly for grassland and sloping land.The soil and water conservation effect is general,and the soil erosion is steep,so the soil erosion caused by rainfall is more Large,adsorbed nitrogen and phosphorus lost more.(3)Compared with the re-classification of land use in the Tieshan Reservoir area,the soil erosion area was reduced by 78.08%,and the soil erosion caused by severe erosion was reduced.84.38%,the effect of returning farmland to forests and returning grass to forests on soil erosion is obvious.(4)By improving the fertilization technology of cultivated land,the cultivated land in the reservoir area will change the fertilization formula,and under the premise of ensuring no reduction in production,the reservoir area can reduce the input of nitrogen 22.35t and reduce the input of phosphorus 1.75t per year.The reduction rates of nitrogen and phosphorus are 29.10%and 15.97%respectively,effective control of the loss of nitrogen and phosphorus pollutants from the source.(5)Estimate the required stable pond design capacity from the relationship between rainfall and runoff,optimize the layout of the stable pond,properly plant aquatic plants in the pond,and regularly harvest and recover the aquatic plants in the pond.