What is referred to as the upper level of the water-saturated zone in the soil?

The upper level of the water-saturated zone in the soil is known as the water table. This term specifically describes the boundary below which the soil and rock layers are completely saturated with water. Above this level, the soil may contain air and is considered unsaturated. Understanding the water table is crucial in various fields, such as hydrology, agriculture, and environmental science, as it impacts groundwater availability, irrigation practices, and the overall health of ecosystems.

Surface water refers to water that is visible on the surface of the ground, such as rivers, lakes, and streams, but it does not describe the water-saturated zone in the soil. Groundwater generally refers to the water that is stored below the water table but does not specify the upper level. An aquifer level represents the height at which groundwater is found in an aquifer, but it is not as precise as referring to the water table, which directly indicates the upper boundary of the saturated zone.