论文部分内容阅读
建立了土壤热、湿、气及盐分耦合运移的数学模型,通过数值模拟研究了地下水深度分别为0.5 m,1.0m,1.5 m和2.0 m,地下水矿化度为5.0×10-3,以及土壤盐分初始质量分数为0时,5 a后土壤溶液中NaCl,KCl,CaCl2和MgSO4分别沿土壤剖面的质量分数分布.计算结果表明相同深度处4种盐分的质量分数大小顺序为:KCl>NaCl>CaCl2>MgSO4,可见扩散系数越大的盐分,其质量分数也越高;地下水位较高时这种差别更大.此外,还分别采用单组分和多组分模型对KCl和NaCl在土壤中的运移进行了比较,发现多组分效应对NaCl的影响更大,而对KCl的影响较小,因此采用多组分模型能够提高NaCl的预报精度.
The mathematic model of the coupling of soil heat, moisture, gas and salt was set up. The groundwater depths were 0.5 m, 1.0 m, 1.5 m and 2.0 m, and the groundwater salinity was 5.0 × 10-3 by numerical simulation. After 5 years, the contents of NaCl, KCl, CaCl2 and MgSO4 in the soil solution along the soil profile were distributed respectively when the initial mass fraction of soil salinity was 0. The calculated results showed that the order of the mass fractions of the four salts at the same depth was KCl> NaCl > CaCl2> MgSO4, the higher the diffusion coefficient is, the higher the mass fraction is, and the higher the groundwater table is, the more obvious difference is between the single and multi-component models, The results show that multicomponent effect has a greater impact on NaCl and less impact on KCl. Therefore, using multicomponent model can improve the prediction accuracy of NaCl.