摘要
溶质运移参数[水动力弥散系数(D)和延迟因子(R)]是预测土壤养分等溶质运移与分布的关键指标,对指导精准灌溉和科学施肥具有重要意义。基于亮蓝染色剂示踪的边界层方法具有花费时间少、应用简单且估算参数唯一等优势。然而,由于亮蓝在土壤运移可能存在滞后现象,无法很好地反映示踪离子的运移特征,从而导致边界层方法估算土壤溶质运移参数存在误差。基于此,以Cl^(-)作为示踪离子,采用5个NaCl溶液浓度梯度作用下(1、2、3、5和10 g/L,分别表示为S1、S2、S3、S5和S10)土壤溶质穿透试验和亮蓝染色剂试验,比较了Cl^(-)溶质穿透曲线和亮蓝示踪Cl^(-)溶质锋运移特征,评价了3种边界层解(二次多项式、三次多项式和指数边界层解)估算精度,并对边界层方法进行了优化。结果表明,NaCl溶液浓度显著影响Cl^(-)运移,表现为浓度越高,Cl^(-)在红壤中越易穿透。与精确解相比,边界层解估算的溶质运移参数和相对浓度剖面差异较大,D的相对误差(RE_(D))、R的相对误差(RE_(R))和Cl^(-)相对浓度(C_(r-Cl))剖面的相对均方根误差(RRMSE)分别为-0.92~0.24、24.73~108.33和0.923~1.396。亮蓝示踪红壤Cl^(-)运移的滞后效应是导致边界层方法误差的主要原因。基于线性优化后的边界层解估算溶质参数的精度显著提高,RE_(D)、RE_(R)和C_(r-Cl)剖面的RRMSE分别为-0.87~6.02、-0.03~2.85和0.008~0.967,其中指数边界层解的优化效果最好,且优化后的边界层方法对S5的溶质运移参数估算效果最好。研究结果可为提高边界层法估算溶质运移参数精度,以及农田水肥精准管理提供科学依据。
The solute transport parameters(hydrodynamic dispersion coefficient D and delay factor R)are key indicators for predicting solute transport and distribution of soil nutrients and other solutes,providing essential guidance for precision irrigation and scientific fertilization.The boundary-layer method using brilliant blue dye tracing offers distinct advantages,such as less time spent,simple application and unique parameter estimation.However,due to the potential hysteresis in brilliant blue transport through soil,its tracing could not accurately reflect the transport characteristics of target ions,leading to some errors in the estimation of soil solute transport parameters using this method.Based on these,the transport behavior of Cl^(-)as a tracer was investigated in a red soil through a breakthrough experiment and a brilliant blue dye experiment with five NaCl concentrations(1,2,3,5,and 10 g/L,denoted as S1,S2,S3,S5,and S10,respectively).The breakthrough curve and the transport characteristics of solute front traced by brilliant blue for Cl^(-)were compared.Moreover,the estimation accuracy of three boundary-layer solutions(quadratic polynomial,cubic polynomial,and exponential boundary-layer solutions)was evaluated,and the boundary-layer was optimized.The results indicated that NaCl concentration significantly influenced Cl^(-)transport,with higher NaCl concentrations facilitating Cl^(-)breakthrough in red soil.Notable discrepancies were observed in the estimated solute transport parameters and Cl^(-)relative concentration(C_(r-Cl))profiles between the boundary-layer solutions and exact solution.The relative error of D(RE_(D))and R(RE_(R)),as well as the root mean square error(RRMSE)of C_(r-Cl) profiles were-0.92-0.24,24.73-108.33,and 0.923-1.396,respectively.The hysteresis of brilliant blue in tracing Cl^(-)transport in red soil was identified as the primary source of boundary-layer method errors.Linear optimization significantly improved the accuracy of parameter estimation,with RE_(D) of-0.87-6.02,RE_(R) of-0.03-2.85,and RRMSE of 0.008-0.967.The optimized exponential boundary-layer solution demonstrated better performance,especially in S5.This study could provide a scientific basis for improving the accuracy of the boundary-layer method in solute transport parameter estimation,as well as for irrigation and fertilization management in agriculture.
作者
高震涛
黄育坤
张卓奇
陈绍民
谭帅
GAO Zhen-tao;HUANG Yu-kun;ZHANG Zhuo-qi;CHEN Shao-min;TAN Shuai(Faculty of Modern Agricultural Engineering,Kunming University of Science and Technology,Kunming Yunnan 650500;Key Laboratory of Efficient Utilization of Agricultural Water Resources and Intelligent Control in Yunnan Province,Kunming Yunnan 650500)
出处
《中国土壤与肥料》
2025年第12期49-60,共12页
Soil and Fertilizer Sciences in China
基金
国家自然科学基金青年科学基金(52009039)
云南省基础研究计划项目(202401AT070325)
云南省科技计划项目(202449CE340014)
国家级大学生创新创业训练计划项目(202310674056)
昆明理工大学2024年学生课外学术科技创新基金(2024ZK118)。
关键词
溶质穿透曲线
亮蓝
边界层方法
溶质运移参数
breakthrough curve
brilliant blue
boundary-layer method
solute transport parameter
