An unconfined aquifer is also known as what?

An unconfined aquifer is commonly referred to as a water table aquifer because it sits just below the surface and has a water table that is not confined by an impermeable layer above it. The water table is the upper surface of the saturated zone, where the soil or rock is fully saturated with water. Changes in precipitation, evaporation, and human activities can directly influence the water table, causing it to rise or fall.

In contrast, the other terms provided refer to different concepts. An artesian aquifer, for instance, is a type of confined aquifer where the water is under pressure and can flow to the surface without pumping. Groundwater aquifer is a broader term that encompasses both unconfined and confined aquifers but does not specifically highlight the characteristics related to the water table. Surface water aquifer is not a recognized term in hydrology, as aquifers refer specifically to subsurface geological formations that can store and transmit water. Thus, referring to an unconfined aquifer as a water table aquifer accurately captures its essential features and role in groundwater hydrology.