降雨强度对小流域土壤溶质流失的影响评估

Impacts of Rainfall Intensity on Soil Solute Loss in a Small Basin

[目的]研究降雨强度对土壤溶质流失的影响。[方法]利用Hydrus-1D模型,对不同降雨强度下太湖宜兴梅林流域水文过程与土壤溶质流失过程进行模拟,并验证了该模型的可靠度。然后,应用该模型模拟了不同雨强下土壤中TN的迁移规律。[结果]Hydrus-1D模型可以很好地反映降水过程中不同深度土壤的水运动过程以及土壤溶质流失过程。次降雨过程中,土壤表层(0～20 cm)TN的流失量占总流失量的95%以上。土壤TN的流失量随着雨强的增大而增加,但是当雨强增至0.030 0 cm/min后,随着降雨强度继续增加,TN流失量仅有微小增加。[结论]该研究为农业非点源污染的治理提供了理论依据。

[Objective] The study aimed to analyze the impacts of rainfall intensity on soil solute loss.[Method] Hydrus-1D model was used to simulate surface runoff process and soil solute loss process under different rainfall intensities in Meilin basin,Yixing City,and its reliability was verified.Afterwards,the model was used to simulate the movement of total nitrogen（TN） in the soil under various rainfall intensities.[Result] Hydrus-1D model had a good effect in the simulation of soil moisture and TN content in surface soil.During the rainfall,TN loss from surface soil（0-20 cm） accounted for above 95% of total loss from the whole soil（0-100 cm）.In addition,TN loss increased with the enhancement of rainfall intensities.However,TN loss tended to be stable when rainfall intensity exceeded 0.030 0 cm/min.[Conclusion] The research could provide theoretical references for the control of agricultural nonpoint source pollution in future.