The top boundary of saturated zones is called the?

• A. Water table
• B. Saturated zone
• C. Aquifer
• D. Unsaturated zone

Answer: (A)

The water table marks the top boundary of the saturated zone. Below this surface, all the pore spaces in the soil or rock are filled with water, forming the groundwater. Above it, the pores contain air and water in varying amounts, which is why that region is called the unsaturated (or vadose) zone. The water table is not a fixed level—it rises with increased recharge from rainfall or irrigation and falls when water is pumped out or during drought. It helps distinguish groundwater from the materials that store and transmit it (the aquifer) and from the region above the water table that isn’t fully saturated.