American Institute of Certified Planners (AICP) Practice Exam

The soils above a water table are referred to as what?

1. Zone of saturation

2. Unconfined aquifer

3. Zone of aeration

4. Groundwater surface

The correct answer is: Zone of aeration

The soils above a water table are referred to as the zone of aeration. This term describes the area where the soil and rock are not fully saturated with water; instead, they contain both air and water in the pore spaces. In this region, water can be found, but it is not enough to saturate the soil completely. The zone of aeration contrasts with the zone of saturation, which lies below the water table, where all the soil pores are filled with water. This concept is crucial in understanding groundwater systems, hydrology, and how water moves through the soil and rock layers. The zone of aeration plays an essential role in the replenishment of groundwater and affects aquifer recharge processes. Recognizing the distinction between the zones of aeration and saturation aids planners in managing water resources effectively and making informed decisions regarding land use and environmental protection.