Interaction of soil water and groundwater during the freezing–thawing cycle: field observations and numerical modeling

Abstract. Freezing-induced groundwater-level decline is widely observed in regions with a shallow water table, but many existing studies on freezing-induced groundwater migration do not account for water-level fluctuations. Here, by combining detailed field observations of liquid soil content and fluctuations at site the Ordos Plateau, China, numerical modeling, we showed that interaction dynamics was controlled wintertime atmospheric conditions topographically driven lateral inflow. With an initial table depth 120 cm inflow rate 1.03 mm d−1, freezing thawing-induced level are well reproduced. By calculating budget groundwater, mean upward flux loss 1.46 d−1 93 d, while recharge as high 3.94 32 d. These results could be useful local resources management when encountering seasonally frozen soils future two- or three-dimensional transient flow semi-arid regions. comparing models under series conditions, found magnitude decreases increases We also fixed-head lower boundary condition would overestimate shallow. Therefore, accurate characterization critical to quantifying contribution hydrological ecological processes cold