A soil with high porosity automatically has high permeability.

• A. True
• B. Sometimes
• C. False
• D. Not necessarily

Answer: (C)

Porosity and permeability are different properties of a soil. Porosity is how much of the soil’s volume is void space, while permeability is how easily water can flow through the pore network. Even with lots of empty space, if the pores are poorly connected or very small, water moves slowly and permeability is low. Clay soils often have high porosity but low permeability because the pores are tiny and not well linked. Conversely, soils with well-connected, larger pores (like coarse sand or gravel) can have high permeability even if they don’t have the highest porosity. So, high porosity does not automatically mean high permeability; the connectivity and size of the pores determine flow.