干旱区生态环境知识资源中心(Arid): 基于COMSOL软件的绿洲盐渍化土壤中多离子耦合运移模型构建

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	基于COMSOL软件的绿洲盐渍化土壤中多离子耦合运移模型构建
其他题名	Modeling of multiple ions coupling transport for salinized soil in oasis based on COMSOL
	焦会青 1; 盛钰 2; 赵成义2 ; 李保国 1
来源期刊	农业工程学报
ISSN	1002-6819
出版年	2018
卷号	34 期号:15 页码:100-107
中文摘要	了解盐分离子在土壤中的迁移规律可以为盐渍土的综合治理以及高效利用提供科学依据,在COMSOL多孔介质和地下水流模块模拟非饱和土壤水流的基础上,自定义偏微分方程组构建盐渍化土壤SO_4~(2-)、Ca~(2+)、Na~+ Cl~-、Mg~(2+)耦合运移模型,考虑阳离子交换过程以及硫酸钙的沉淀溶解反应,并通过新疆绿洲膜下滴灌田间试验对模型进行检验,对比不同活度系数估算方法对模拟结果的影响。结果表明,各离子模拟值与实测值吻合较好,平均相对误差介于9.15%~28.57%,决定系数介于0.41~0.88,该模型能够较好地反映土壤中盐分离子的动态变化规律;在膜下滴灌条件下,膜下0~40cm土层的盐分离子有不同程度的淋洗,Cl~-和Na~+的淋洗效果好于Ca~(2+)和SO_4~(2-);活度系数的估算对模拟结果的准确性有重要影响,尤其是盐分含量较高时,采用通用的函数关系可能会带来较大的模拟误差。
英文摘要	Soil salinization constrains sustainable development of agriculture in arid area. Understanding dynamics of soil salt ions is helpful for the comprehensive treatment and high-efficient utilization of salt-affected soils. COMSOL is a flexible numerical simulation software based on finite element theory, with which one can freely define any type of function capable of describing material properties, sources or sinks, and boundary conditions. In addition, one can define a unique set of partial differential equations for describing certain physics phenomena that are not included in the preset modules in COMSOL. Based on these strengths, we reported a modeling study of SO_4~(2-), Ca~(2+), Na~+,Cl~-,and Mg~(2+) dynamics in salt-affected soil using COMSOL. Soil water flow was described using the Richards equations in porous media and subsurface flow module. Salt ions transports were simulated by the advection-dispersion equations in the presence of cation exchange, precipitation and dissolution of calcium sulfate, which were built in the user-defined partial differential equations module. The cation exchange was described by the Gapon equation, and the chemical reaction between Ca~(2+) and SO_4~(2-) was described using the second-order equation. We further verified the model with an example of mulched drip irrigation with different irrigation amounts. The simulated soil water contents and ion concentrations in soil solution were generally in good agreement with the experiment measurement. The mean absolute error values for soil water contents ranged from 0.023 to 0.033 cm~3/cm~3, and the root mean square error values for those ranged from 0.030 to 0.040 cm~3/cm~3. For all the ions in soil solution, the mean relative error values ranged from 9.15% to 28.57%, and the coefficients of determination ranged from 0.41 to 0.88. It indicated that the model was capable of describing the dynamics of soil salt ions under field conditions. In the mulched drip irrigation system, all the concentrations of salt ions in soil solution decreased in the upper layer (around 40 cm) of the mulched soil after the irrigation, and then increased gradually due to water uptake of root and chemical reaction, or both. As Ca~(2+) and SO_4~(2-) in soil solution were replenished by the dissolution of calcium sulfate, their concentrations increased more rapidly than those of Cl~- and Na~+,which indicated that Cl~- and Na~+ were leached more easily. However, all the ions gradually accumulated on the exposed soil surface, and the accumulation amount of Cl~- was the biggest due to its strong mobility in soil. In addition, the simulation results based on different activity coefficient equations, i.e., Davies equation and the exponential equation fitted from the measured values, were compared. The activity coefficient values calculated from the Davies equation were generally larger than those calculated from the fitted exponential equation. As a result, the simulated Ca~(2+), SO_4~(2-), Na~+, and Mg~(2+) concentrations in soil solution based on the Davies equation were generally lower than those based on the fitted exponential equation, especially for Ca~(2+) and SO_4~(2-). The results suggest that the calculation method of activity coefficient has obvious effect on the model accuracy, and general activity coefficient equation might lead to considerable simulation errors for saline soil.
中文关键词	土壤 ; 灌溉 ; 模型 ; 盐分离子 ; 离子运移 ; 离子反应 ; 膜下滴灌
英文关键词	COMSOL soils irrigation model salt ions COMSOL ions transport ions reaction mulched drip irrigation
语种	中文
国家	中国
收录类别	CSCD
WOS类目	AGRICULTURE MULTIDISCIPLINARY
WOS研究方向	Agriculture
CSCD记录号	CSCD:6290230
来源机构	中国科学院新疆生态与地理研究所 ; 中国农业大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/237985
作者单位	1.中国农业大学资源与环境学院, 农业部华北耕地保育重点实验室;;国土资源部农用地质量与监控重点实验室, 北京 100193, 中国; 2.中国科学院新疆生态与地理研究所, 乌鲁木齐, 新疆 830011, 中国
推荐引用方式 GB/T 7714	焦会青,盛钰,赵成义,等. 基于COMSOL软件的绿洲盐渍化土壤中多离子耦合运移模型构建[J]. 中国科学院新疆生态与地理研究所, 中国农业大学,2018,34(15):100-107.
APA	焦会青,盛钰,赵成义,&李保国.(2018).基于COMSOL软件的绿洲盐渍化土壤中多离子耦合运移模型构建.农业工程学报,34(15),100-107.
MLA	焦会青,et al."基于COMSOL软件的绿洲盐渍化土壤中多离子耦合运移模型构建".农业工程学报 34.15(2018):100-107.