Which term describes the region that remains above the water table?

The term that describes the region remaining above the water table is the unsaturated zone. In geological terms, the unsaturated zone is also referred to as the vadose zone, encompassing soil and rock layers containing air and water but not saturated with it. This region allows for the movement of water downward through gravitational and capillary forces but does not have all its pore spaces filled with water.

Understanding the composition of groundwater zones provides clarity about water availability and movement. The saturated zone, in contrast, is the area below the water table where all the pore spaces are filled with water, which is essential for understanding groundwater storage and aquifer properties. Knowing these distinctions helps in groundwater management and resource planning.

Other terms like aquifer zone refer to specific types of saturated zones capable of yielding usable amounts of water and thus do not accurately describe the region above the water table. Pore zone is not a recognized term in hydrology and doesn't denote a specific zone related to water saturation levels.