What happens to the water table during periods of heavy rainfall in an unconfined aquifer?

During periods of heavy rainfall, the water table in an unconfined aquifer rises. An unconfined aquifer is directly influenced by surface water and precipitation because it is not confined by an impermeable layer above it. When heavy rainfall occurs, the excess water from the surface infiltrates into the ground, replenishing the aquifer and leading to an increase in the volume of water that fills the pore spaces in the soil and rock. This influx of water results in a higher water table, which can lead to the saturation of soils and potentially contributes to surface water bodies like lakes and rivers also rising due to increased groundwater levels.

On the other hand, the other options are not applicable during heavy rainfall. The water table does not remain unchanged or lower, as these would suggest no input of water or an extraction of water from the aquifer, which typically does not happen during heavy rainfall. Freezing is also not relevant in this context since freezing would not typically apply to groundwater levels. When considering these factors, the rise of the water table due to precipitation is the only correct phenomenon.