What is the name of upper level of groundwater?

Water table

The correct answer is option 2. Water table.

The water table is the upper surface of the saturated zone in an aquifer, where the pores and fractures in the rock or soil are completely filled with water. Below the water table, the subsurface is saturated with water, and above it, there is a zone where the soil or rock is not fully saturated and contains both water and air.

Here is a brief explanation:

1. Saturated Zone:  This is the region below the water table where the pores in the soil or fractures in the rock are filled with water. Groundwater is found in this zone.

2. Unsaturated Zone: Above the water table, there is the unsaturated zone where the soil or rock contains both air and water. The water content in this zone decreases with height until you reach the water table.

The water table is not constant and can change due to various factors such as precipitation, groundwater extraction, and seasonal variations. In areas with abundant rainfall or recharge, the water table may rise, while in drought conditions or areas of high groundwater extraction, it may lower. The water table is a critical concept in hydrogeology and helps in understanding groundwater movement and availability.