Atmospheric precipitation and surface runoff through the purification effect of the air-bearing zone and become the underground runoff (also shown to include the loam in the flow) collectively referred to as groundwater. Groundwater source is generally referred to, good water quality, wide distribution, not easily polluted, strong storage capacity, high degree of assurance of water supply, and has been widely exploited and utilized part of the groundwater.

The terminology: air pocket refers to the geologic medium located below the earth's surface and above the submerged surface.