Study On The Simulation Of Agricultural Non-point Source Pollution In Huaihe River Basin In Henan Provice

Non-point source pollution lead to eutrophication of lake, surface flow and groundwater pollution, seriously threaten the safety of drinking water and water environment, and the development of China's economic and social. Simulation of agricultural non-point source pollution characteristics and quantifying its pollution load in Huaihe river basin in Henan province has an important meaning for environment planning and management, guiding sustainable development of economy and society in this region.Based on the summary of non-point source pollution concept, research status and significance, this paper selected the common soil in Henan province of cinnamon soil, fluvo-aquic soils , Shajiang black soil, Yellow cinnamon soil and Yellow brown soil, the agricultural non-point source pollution with different precipitin intensity of simulated 0.5, 1.0, 1.5, 2.0, 2.5, 3 mm·min-1, the organic, nitrogen and phosphorus loss with the surface flow was also studied .At the same time, this paper also studied the influence of straw counters field and soil types on nutrient loss. The results shows as follows:(1)Tested soil Initial permeability, Stable penetration of size: Yellow cinnamon soil > Yellow brown soil > fluvo-aquic soils > cinnamon soil > Shajiang black soil. Soil bulk density and negatively correlated soil permeability, soil water infiltration performance and soil the capillary porosity was positively associated with capillary porosity a negative correlation.Permeability declines greatly at the beginning stage, with the passage of time, the declines gradually decreases, and finally achieve steady infiltration, and generally in 20³0min achieve steady infiltration.(2)Summarizes the produce and runoff sediment yield in the loss of sediment nutrient elements, and accordin power exponent equation and linear equation five kinds of soil types runoff and sediment quantity, between runoff and nutrient losses, with nutrient loss accorting to the quantitative relationship between.(3) Research cinnamon soil and fluvo-aquic soils two farmland soil, straw countersfield of runoff sediment yield after runoff, and the influence of nutrient loss. Points out that straw counters-field measures, can reduce the runoff sediment production, but runoff nutrients increasing concentration of nutrient, if encounter summer rainfall can cause greater nutrient losses. Joining the straw stalk after 60min ,the total phosphorus content loss in runoff, when the precipitation intensity is 1.00mm·min^-1 ,increased 289.28 %;1.5 mm·min^-1 increased 160.40 %, 2.5 mm·min^-1 increased 67.83%. The total nitrogen content loss in runoff, 1.0 mm·min^-1 increased 8.00 %, 1.5 mm·min^-1 increased 0.54 %, 2.5 mm·min^-1 increased 38.34%. 1.0 mm·min^-1 60min average COD value increased 522.23%, 1.5 mm·min^-1 increased 369.98%, 2.5 mm·min^-1 increased 337.47%.(4) Research cinnamon soil, fluvo-aquic soils, shajiang black soil andyellow cinnamon soil, yellow brown soil, under different rainfall intensity, runoff sediment and nutrient loss characteristics. Found in the same slope, the runoff, farmland produces less than woodland, but the difference is small; And farmland sediment is less than woodland; The erosion of nutrients with the runoff, the difference is smaller beteen farmland and woodlands; With silt erosion nutrients, farmland far outclass woodland. Compaire Farmland soil to woodland soil, sediment discharge increased 1178%^-16018%.Sediment ; the loss of TN with sediment discharge, increased 3620%¹1598%; the loss of TP with sediment discharge 1010% 81.40%; the loss of organic matter with sediment discharge increased 2063% ¹4648%.(5) The main losing of nutrient way in cinnamon soil, fluvo-aquic soils, shajiang black soil is losing with sediment discharge, but in yellow cinnamon soil and yellow brown soil, nutrient with runoff lose more than with sediment discharge. For farmland soil, compare sediment discharge to runoff, the loss of TN increased 670%²555%; the loss of TP increased 5397%¹0992%;the loss of organic matter increased 280%⁸50%.For woodland soil, compare sediment discharge and runoff, the loss of TN reduce 13%²2%; the loss of TP increased 184%⁶60%; the loss of organic matter reduce 4%¹4%.(6)Through the research suggests that should be considered when straw counters-field denagrowth time, make completely suitable decay time and rainfall season stagger. Woodland although nutrient loss, but far less farmland, forest area, by the influence of river in formulating should be considered when the load on the farms and woodland river comprehensive load.