摘要
[目的]有效混合深度是量化与预测溶质流失的重要参数,量化质地差异土壤的有效混合深度,探究土壤侵蚀产流产沙和溶质流失有效混合深度的响应对农业面源污染模型的研究具有重要意义。[方法]以丹江口库区5个质地差异的旱耕地表土为研究对象,采用溴离子示踪法,根据溴不同的施放深度[0(表层)、0.5、1、2、5 cm],通过模拟降雨试验量化质地差异土壤的有效混合深度及其动态变化,测定土壤侵蚀产流产沙及溶质流失过程,分析其对有效混合深度的响应。[结果]在设定的试验条件下,随着黏粒质量分数的增加,降雨过程中有效混合深度分别分布在0.32~0.72、0.11~0.57、0.44~2.41、0.11~1.04、0.13~0.28 cm,土壤质地显著影响有效混合深度(F=39.27、p<0.001),但因不同质地土壤入渗及产流过程的差异,二者并未表现出明显线性关系。有效混合深度在降雨过程中呈动态变化,随降雨历时呈明显的幂函数关系(R^(2)>0.80)。不同有效混合深度下的土壤侵蚀产流产沙过程也存在显著差异(F>12.068、p<0.001)。回归分析表明,平均有效混合深度与土壤累计径流量和累计溴流失量呈显著线性关系(R^(2)>0.92),与产沙率、泥沙浓度及累积产沙量呈显著指数函数关系(R^(2)>0.94)。[结论]质地差异土壤的有效混合深度存在显著差异,并且有效混合深度与侵蚀产流产沙和溶质流失指标间存在显著的线性或指数函数关系,可通过侵蚀产流产沙特征对有效混合深度反演,以提高溶质流失模型预测精度。
[Objective]The effective mixing depth is an essential parameter for quantifying and predicting solute loss.It is of great significance to quantify the effective mixing depth of texture-differentiated soils and investigate the response of effective mixing depth to soil erosion,and solute loss in the modeling of agricultural non-point source pollution.[Methods]The topsoils of five texturally distinct dry croplands in the Danjiangkou Reservoir Region were selected as the research object.The bromine ion tracer method was employed to quantify the effective mixing depth and its dynamic changes in texturally distinct soils.Simulated rainfall tests were conducted according to different bromine application depths[0 (soil surface),0.5,1,2 and 5 cm]to determine the process of soil erosion and solute loss and analyze their responses to the effective mixing depth.[Results]Under the experimental conditions established in this study,the effective mixing depths during rainfall exhibited a range of 0.32—0.72,0.11—0.57,0.44—2.41,0.11—1.04,and 0.13—0.28 cm.The effective mixing depths were found to be significantly affected by the clay content and soil texture (F=39.27,p<0.001).However,the effective mixing depths of different textured soils were significantly affected due to the differences in infiltration and flow production processes of different soil textures.Consequently,a significant linear relationship was not observed between the two.Furthermore,the effective mixing depth demonstrated a dynamic variation during the rainfall process,and exhibited a pronounced power function relationship with rainfall duration (R^(2)>0.80).Furthermore,a notable distinction was observed in the soil erosion and sand production processes across varying effective mixing depths(F>12.068,p<0.001).Regression analysis demonstrated that the mean effective mixing depth exhibited a significant linear correlation with cumulative soil runoff and cumulative bromine loss (R^(2)>0.92),as well as a significant exponential function relationship with sand production rate,sediment concentration,and cumulative sand production (R^(2)>0.94).[Conclusion]The effective mixing depths of various textured soils exhibit notable disparities.A substantial linear or exponential correlation exists between the effective mixing depth,soil erosion,and solute loss indices.This correlation can be inverted through the runoff generation and sediment yield characteristics of the effective mixing depth,thereby enhancing the precision of the solute loss model.
作者
王杰
郑好
李梓涵
任少聪
王硕果
连啟洁
魏玉杰
蔡崇法
WANG Jie;ZHENG Hao;LI Zihan;REN Shaocong;WANG Shuoguo;LIAN Qijie;WEI Yujie;CAI Chongfa(College of Resource and Environment,Huazhong Agricultural University,Wuhan 430070,China)
出处
《水土保持学报》
北大核心
2025年第2期65-73,81,共10页
Journal of Soil and Water Conservation
基金
国家自然科学基金项目(42077067)
国家级大学生创新创业训练计划项目(202410504020)。
作者简介
第一作者:王杰(1992-),男,博士研究生,主要从事水土保持及面源污染研究。E-mail:wj6377@163.com;通信作者:魏玉杰(1989-),女,副教授,主要从事水土保持与崩岗侵蚀研究。E-mail:wyj@mail.hzau.edu.cn。
