蒸发条件下不同地下水位夹砂层土壤水盐运移特性研究

针对滨海盐碱地地下水位浅，春秋易强烈返盐，园林绿化需微区换土和铺设隔盐层的特点。通过室内土柱试验，研究了夹砂层的级配和地下水埋深等因素对土壤水盐迁移特性的影响。结果表明，地下水位相同时，夹砂层对水分和盐分的抑制率为石硝>细砂>液态渣，即水盐的迁移率随砂层级配的变差而增大；砂层级配一致时，地下水埋深为110cm的各夹砂层的水分和盐分抑制率均大于地下水位为80cm的。砂层对水分的抑制率随蒸发历时的延长而减小，但各砂层对盐分的抑制率随蒸发历时的延长而增加；蒸发30d后，同一历时砂层对水分的抑制率小于对盐分的抑制率。该研究为滨海盐碱地的改良以及灌溉和排水等措施的制定提供了参考。

Characteristics of water and salt transport in sand-layered soil underevaporation with the different ground water level

Considering the fact that there were the coastal saline-alkali soil characteristics of shallow groundwater levels,spring and autumn easy to back salt intensely,micro-area required to change soil and lay across sand layer separated salt for landscaping.The impacts of sand porticle distribution of sand-layered soil and groundwater depth on water and salt migration characteristics were analyzed through the indoor soil columns experiment.The results show that the sand inclusion level of the water and salt inhibition rate was stone glass> small sand > liquid slag at the same ground water phase,namely, the migration rates of water and salt were intensified for the treatments with the worse sand distribution;when the sand-level distribution was consistent, the inhibition rates of water and salt in the groundwater table of 110cm were higher than the groundwater level of 80cm’s. The sand on the inhibition rate of water reduced with the evaporation lasted extension,however, the sand on the salt rejection increased with the extension of duration increased evaporation;after 30d’s evaporation,the effect of the sand layer against salt transport was more than the effect against water transport at the same evaporation duration. The study had provided a reference for coastal saline-alkali soil’s improvement as well as irrigation and draining water formulations.