Freeze-thaw effect on soil water migration and groundwater level fluctuation

Different from areas of non-frozen soil, seasonal freezing and thawing of soil significantly affects soil water movement and groundwater level dynamics, resulting in altered hydraulic conditions and pollutant distribution characteristics in groundwater and soil environment. Specific quantifications in the fluctuation process of groundwater levels under freeze-thaw conditions have not been performed before. Therefore in the present work we established a device to simulate freeze-thaw cycle for moisture migration in aerated zones and aquifers, to quantitatively analyze different particle sizes and different temperature conditions. Differences in water level fluctuation due to freezing and thawing process indicated that freezing and thawing had direct effects on soil water migration and groundwater levels. Changes in groundwater levels in the freeze-thaw process corresponded to freeze-thaw stage of soil, and hysteresis was observed. Soil media conditions and temperature conditions were found to have marked effect on fluctuations in groundwater during freeze-thaw process. With larger amount of water migration, the water level fluctuations become more significant.