裸地蒸发过程土壤盐分运移的实验及数值模拟研究

本文利用农田灌溉研究所洪门试验场地中渗透仪,对不同地下水埋深条件下裸地蒸发过程粉砂壤土的盐分运移进行了实验及数值模拟研究。结果表明,对于三种地下水埋深,即150cm、200cm和250cm,在无降雨裸地蒸发情况下,表层积盐均不明显;但在有小水量降雨和裸地蒸发情况下,地下水埋深为150cm的表层积盐强烈。地下水埋深为200cm及250cm的表层土壤虽有积盐,但积盐量较小,这种积盐主要是上层土壤中盐分的重新分布。

Studies through Experiments and Numerical Simulation on the Movement of Salt under Condition of Open-air Evaporation

Experiments and numerical simulation on the movement of salt under the condi-tion of different ground water tables and open-air evaporation are introduced, using lysimeter located at Hongmen Experiment station of Farmland Irrigation Research In-stitute. The result indicated that under the condition of open-air evaporation,there was no significant salt accumulation in soil surface when depths to the ground water table were 150cm. 200cm and 250cm respectively.Under the condition of open-air evapora-tion with small amount of precipitation,significant salt accumulation occurred in the surface layer, when depth to ihe ground water table was 150cm. For the other two ground water tables. There were slight salt accumulation in sail surfatce as the result of salt redistribution in the top soil.