Hydrological Cycle & Drainage Basin Systems Practice Test 2026 – The Comprehensive All-in-One Guide for Success!

Infiltration is the entry of water from the ground surface into the soil. When rain, snowmelt, or irrigation reaches the soil, some of the water soaks downward into the soil depending on how permeable the surface is, how wet the soil already is, and how much vegetation or surface cover slows or aids the flow. This step sets up soil moisture and can lead to groundwater recharge as the infiltrated water moves deeper over time.

Percolation is the next stage after infiltration, referring to water moving downward through the soil profile toward groundwater. The other options describe broader concepts rather than the specific process of water entering the soil from the surface.