Which process involves downward movement of water through soil due to gravity?

Which process involves downward movement of water through soil due to gravity?

• A. Throughflow
• B. Infiltration
• C. Percolation
• D. Open System

Answer: (C)

Percolation describes the downward movement of water through the soil and into the deeper layers under the influence of gravity. When water reaches the soil surface, it first infiltrates into the pore spaces. Once inside, gravity pulls the water downward through the soil’s connected pores and cracks, moving the moisture through the soil profile toward the groundwater. The speed of this vertical drainage depends on soil permeability and texture—well-drained sands let it move quickly, while clays slow it down. Infiltration is the entry of water into the soil from the surface, not its downward travel; throughflow is movement within the soil, often laterally and downslope, and an open system is a boundary concept, not a transport process.

Percolation describes the downward movement of water through the soil and into the deeper layers under the influence of gravity. When water reaches the soil surface, it first infiltrates into the pore spaces. Once inside, gravity pulls the water downward through the soil’s connected pores and cracks, moving the moisture through the soil profile toward the groundwater. The speed of this vertical drainage depends on soil permeability and texture—well-drained sands let it move quickly, while clays slow it down. Infiltration is the entry of water into the soil from the surface, not its downward travel; throughflow is movement within the soil, often laterally and downslope, and an open system is a boundary concept, not a transport process.