基于COMSOL的低渗性盐土内设砂柱洗盐定量模拟  

Simulation of Salt Leaching in Coastal Saline Soil Denoting Sand Columns Based on COMSOL

作　　者：孙雪雁[1,2] 李品芳[1] 李保国[1] 薛元霞[2] 邵蕾[2] 

机构地区：[1]中国农业大学农业部华北耕地保育重点实验室,北京100193 [2]中国农业大学烟台研究院,烟台264670

出　　处：《农业机械学报》2014年第7期111-117,124,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：'十二五'国家科技支撑计划资助项目(2012BAD05B02);国际原子能机构国际联合研究计划资助项目(CRP D1.20.13-17865)

摘　　要：滨海粘壤质盐土具有质地黏重、渗透性差等特点,工程实践中一种有效的措施是在其土体中建构砂性土柱(简称砂柱)加速其脱盐。针对此工程措施,基于2-D土壤溶质运移模型,应用COMSOL软件模拟了饱和淋洗条件下3种类型砂柱设置的排盐效果,并进行了定量分析。结果表明:内设中竖砂柱、单斜对角砂柱和双斜'X'型长砂柱,经过24h淋洗后,其淋洗效率分别是不设砂柱的1.24、1.29和1.45倍;95%盐分的淋出时长分别为不设砂柱的0.88、0.83和0.78倍。这说明内设砂柱能显著提高脱盐效率,不同砂柱构建对脱盐效率也有显著影响,3种砂柱相比,内设双斜'X'型长砂柱的构型最有利于盐分的淋洗,也最节省水资源。Based on COMSOL （3.5）, two-dimensional transient cross-sectional models were used to investigate water and solute transport in the soil column coupled with variable sand column forms, with ＂a＂ denoting no sand column, ＂b＂ with one vertical middle sand column, ＂c＂ with one long slanged sand column, ＂d＂ with two long slanged X-shaped sand columns. The results showed that sand column obviously increased the transport efficiency of water and salt, which may attribute to the higher hydraulic conductivity and higher diffusion coefficients in sand columns than clay-loam coastal saline. The efficiency of sand column depends on its position and its angle accordingly. The slanted columns were overall superior to the vertical ones in transport efficiency. Generally, ＂d＂ is the best type, ＂e＂ is the second best and ＂b＂ is the third, according to the efficiency of salt leaching and the efficiency of the utilization of water resources.

关 键 词：滨海盐土 溶质运移 COMSOL 2-D砂柱 数学模拟 

分 类 号：S156.42[农业科学—土壤学]