The upper layer of the permanently saturated zone within solid rocks and sediments is the water table.

The upper layer of the permanently saturated zone within solid rocks and sediments is the water table.

• A. Phreatic zone
• B. Discharge
• C. Permeability
• D. Water table

Answer: (D)

The water table is the upper surface of the groundwater, or permanently saturated, zone in rocks and sediments. Below this surface, all the pore spaces are filled with water, allowing groundwater to flow. Above it, the pores are not fully saturated and contain air, forming the unsaturated (vadose) zone. The water table can move up or down with changes in recharge (rainfall, infiltration) and discharge (uptake by wells or streams). The other terms describe either the saturated zone as a whole (phreatic zone) or processes/properties (discharge, permeability) rather than the boundary itself.

The water table is the upper surface of the groundwater, or permanently saturated, zone in rocks and sediments. Below this surface, all the pore spaces are filled with water, allowing groundwater to flow. Above it, the pores are not fully saturated and contain air, forming the unsaturated (vadose) zone. The water table can move up or down with changes in recharge (rainfall, infiltration) and discharge (uptake by wells or streams). The other terms describe either the saturated zone as a whole (phreatic zone) or processes/properties (discharge, permeability) rather than the boundary itself.