Transformation between phreatic water and soil water during freeze–thaw periods
Date
2018Author
Chen, Junfeng
Gao, Xuguang
Zheng, Xiuqing
Miao, Chunyan
Liu, Ping
Du, Qi
Xu, Yongxin
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Show full item recordAbstract
During freeze–thaw periods, the exchange between shallow groundwater and soil water is
unusually strong and bidirectional, which causes soil salinization and affects the accuracy of water
resources assessment. The objectives of this study were to explore the laws of transformation between
phreatic water and soil water through nine different groundwater table depths (GTDs) and three
kinds of lithologies during three successive freeze–thaw periods using field lysimeters. The results
showed that phreatic evaporation increased with smaller average soil particle sizes. The differences
between phreatic evaporation and recharge to groundwater (DPR) and GTDs were well fitted by the
semi-logarithmic model, and the regression coefficients A and B of the model were well fitted by the
linear relationship with the average soil particle size. With the increase of soil particle size, the change
of DPR decreased with the change rate of soil particle size. The extent of transformation between
phreatic water and soil water decreased with the increase of soil particle size. During the whole
freeze–thaw period, the negative value of DPR increased with an decrease in GTD. The groundwater
depths of zero DPR (D-zero) of sandy loam, fine sand and sandy soil during the freeze–thaw periods
were 2.79 m, 2.21 m and 2.12 m, respectively. This research is significant for the prevention of soil
salinization disasters and the accurate assessment of water resources.