Effect of seasonal freeze-thaw process on spatial and temporal
distribution of soil water and its infiltration to recharge groundwater
Abstract
Clarifying the distribution and dynamics of soil moisture during the
freeze-thaw process is crucial for surface ecology and is an objective
requirement to investigate the mechanism of changes during the
groundwater recharge process in a freeze-thaw zone. Based on the
monitoring data of soil moisture and temperature in the Changbai
Mountain area, the freeze-thaw process is classified into four periods.
This study investigates the hydrothermal migration processes during
different periods. The simultaneous heat and water model is used to
simulate and analyze the infiltration of soil moisture into groundwater
under five precipitation guarantee rates. The results are as follows:
(1) The smaller the soil depth, the stronger is the correlation between
soil temperature and air temperature during the freeze-thaw process. (2)
The redistribution of soil moisture before and after freeze-thaw is
significantly affected by the soil texture, and soil permeability
affects the recharge of soil moisture from the upper region to the lower
region during the thawing period. (3) Groundwater receives vertical
infiltration recharge mainly during non-freezing and is supplied by
freezing and snowmelt recharge during the stable thawing period. The
percentage of soil water infiltration during the stable thawing period
in the total annual infiltration increases gradually with the
precipitation guarantee rate.