Which property describes the ability for water to move through soil?

• A. Porosity
• B. Permeability
• C. Capillarity
• D. Density

Answer: (B)

Permeability is the property that describes how easily water can flow through soil. It depends on how connected and spacious the pore spaces are: well-connected, larger pores let water move through more readily, while very small or poorly connected pores slow or block flow. Porosity tells you how much pore space is available to hold water, but not how fast water can move. Capillarity describes how water can rise or move in tiny pores due to cohesive and adhesive forces, which affects movement in fine-grained soils but isn’t the overall ease of flow through the soil. Density relates to mass per volume and doesn’t directly describe flow through pore networks. So, the term that best describes the ability for water to move through soil is permeability.