What term describes the movement of water within porous materials?

The term that describes the movement of water within porous materials is capillary action. This phenomenon occurs when water moves through tiny spaces in materials, such as soil or plant tissues, due to the combined effects of adhesion (the attraction between water molecules and the surfaces of the materials) and cohesion (the attraction between water molecules themselves).

In capillary action, water can overcome gravity and move upward or across a material. This is particularly significant in plant biology, as it allows roots to access water that is held in the soil, even when it is not directly saturated. The ability of water to move through porous media is crucial for various processes, including soil moisture retention and the transport of nutrients in plants.

Other terms like infiltration, evaporation, and transpiration may involve water movement or changes in state, but they do not specifically describe the mechanism of water movement through porous materials. Infiltration refers to the movement of water into the soil surface, while evaporation is the process of converting liquid water into vapor. Transpiration, on the other hand, involves the release of water vapor from plant leaves into the atmosphere.