Study On Characteristics Of Phosphorus Loss In Non-point Source Pollution Under Different Slope And Rainfall Intensity

The increasing eutrophication of water is closely related to the emission problem of nitrogen and phosphorus in agricultural non-point source pollution.Fertilization structure is irrational,excessive and excessive application of chemical fertilizers and so will make the soil in the rich state of phosphorus.Soil retained in the soil with the soil erosion,surface runoff and leaking leaking in several ways into the surface and underground water environment and continue to accumulate,and ultimately cause water eutrophication.Therefore,it is very important to study the law of phosphorus loss in non-point source pollution.In this paper,the simulation experiment was carried out by planting the Chinese cabbage and using the artificial rainfall system.The concentrations of total phosphorus,dissolved phosphorus and particulate phosphorus in surface runoff and soil leakage under different rainfall intensity and slope gradient were measured.Summing up the analysis of its changes and influencing factorsThis paper first studied on characteristics of phosphorus loss in non-point source pollution under different slope.The conclusions are as follows:The concentration of total phosphorus and particulate phosphorus in surface runoff is positively correlated with slope gradient.And the concentration of dissolved phosphorus was negatively correlated with the slope.The concentration of total phosphorus and dissolved phosphorus in runoff water and the concentration of total phosphorus,dissolved phosphorus and particulate phosphorus in ungroundwater leakage at 20 cm and 40 cm were negatively correlated with the slope.Under different slope,the concentration of total phosphorus,dissolved phosphorus and particulate phosphorus decreased with the increase of soil depth.When the slope is large(15 °.20°),the particulate phosphorus is the main form of phosphorus loss in surface runoff.When the slope is smaller(5 °,10°),the loss of particulate phosphorus and dissolved phosphorus in surface runoff is quite.The main forms of phosphorus loss in ungroundwater leakage at 20 cm and 40 cm were dissolved phosphorus under different slope.This paper second studied study on characteristics of phosphorus loss in non-point source pollution under rainfall Intensity.The conclusions are as follows:The concentration of total phosphorus,dissolved phosphorus and particulate phosphorus in surface runoff and soil leakage at 20 cm and 40 cm is positively correlated with rainfall intensity.Under different rainfall intensity,the concentration of total phosphorus,dissolved phosphorus and particulate phosphorus decreased with the increase of soil depth.When the rainfall intensity is smaller(30 mm/h,60 mm/h),the loss of particulate phosphorus and dissolved phosphorus in surface runoff is quite.When the rainfall intensity is larger(90 mm/h,120 mm/h),the particulate phosphorus is the main form of phosphorus loss in surface runoff.The main forms of phosphorus loss in soil leakage at 20cm and 40cm were dissolved phosphorus under different rainfall intensity.Through the above research,the characteristics of the soil phosphine under certain conditions and its influencing factors were studied.This paper provides some theoretical support and guidance for the study of the effect of different rainfall and different slope topography on the pollution of rural face source.