What does permeability measure?

Permeability measures the rate at which water flows through soil, reflecting how easily water can move through the soil’s pore spaces. This property is crucial for understanding drainage, groundwater movement, and the infiltration of water into the soil. Soils with high permeability, such as sandy soils, allow water to flow quickly, while soils with low permeability, like clay, slow down this process significantly. This measurement is essential in various applications, including agriculture, construction, and environmental management, as it affects how water interacts with the soil and can impact plant growth and groundwater recharge.

In contrast, the other choices refer to different soil properties. The capacity of soil to retain water relates to its water-holding capacity and is influenced by factors such as soil texture and structure, but it does not measure flow rates. The volume of water that soil can hold connects to water retention rather than flow. Lastly, resistance to erosion pertains to how well the soil can withstand the forces of wind and water without being worn away, which is a distinct concept from permeability.