The endless circulation of water between oceans, atmosphere and land is called the hydrologic cycle. The circulation is primarily governed by solar energy. The gravity inflow to the hydrologic cycle arrives as precipitation in the form of rainfall or snowmelt. Outflow takes place as stream flow, evaporation from open bodies of water/soil surface and transpiration from the soil by plants.

As the rain fall on the earth, some flows down hill as run off into a stream, lake or ocean. Some evaporates, some is taken up by plants. The rest trickles down through subsurface soil and rock. This water eventually reaches the water-table. Water from the water table is discharged in wetlands, lakes and streams at places where the water-table meets the land surface. The sun causes evaporation from these surface water and water vapor accumulates in the atmosphere and clouds begin to form , the hydrologic cycle thus begins - a new.

Groundwater - the buried treasure

The word groundwater should be considered as a complex medium composed of ground and water. While both the components are complimentary and interactive they influence in the resulting characteristics of groundwater. groundwater is an increasingly important resource all over the world. The term groundwater is usually reserved for the subsurface water that occurs beneath the water-table in soils and geologic formation that are fully saturated. Geo-chemically, groundwater is aqueous solution of bicarbonates, chlorides and sulphates of alkaline earth and alkali metals. It supports drinking water supply, livestock needs irrigation, industrial and many commercial activities. While the degree of reliance on groundwater varies significantly, the need of groundwater as a dependable resource of fresh water has been unquestionable.

In the overall geo-strategic scenario groundwater has also offered a medium for many environmental solutions. It is key to under standing a wide variety of geologic processes for eg.- the generation of earthquakes, the migration and accumulation of petroleum and the genesis of certain type of ore deposits, soil type and land forms.