In the process of groundwater and surface water cycles, which process enables groundwater recharge?

• A. Evaporation
• B. Condensation
• C. Transpiration
• D. Infiltration

Answer: (D)

Groundwater recharge happens when water from the surface moves down into the aquifer. The process that makes this possible is infiltration—the downward movement of water from the surface into the soil, where it percolates through the unsaturated zone until it reaches the saturated zone. This downward seepage is driven by gravity and depends on soil properties like porosity and permeability, as well as land cover and moisture conditions. If water infiltrates, it can replenish groundwater; if the surface is impermeable or rainfall is too intense, water stays on the surface as runoff rather than recharging the groundwater. Evaporation and transpiration remove water to the atmosphere, while condensation occurs in the atmosphere, so they don’t directly replenish groundwater. Infiltration is the mechanism that enables groundwater recharge.