What is the meaning of Groundwater?
Groundwater is the water that lies below the surface of the ground and fills the pore space as well as cracks and other openings. Most sedimentary rocks can hold a large percentage of water. Loose sand may have a porosity of up to 40 percent; however, this may be reduced by half as a result of recrystallization. For a rock to be permeable, openings must be interconnected. Rocks such as sandstone and conglomerate have a high porosity because they have the capacity to hold much water.
Why is Groundwater so important?
Ground water is the second largest reservoir of water in the hydrologic cycle. But more importantly, it is the predominant source of drinking water in many states.Groundwater, which is in aquifers below the surface of the Earth, is one of the Nation's most important natural resources, apparently.
Groundwater is the chief source of about 33 percent of the water that country and city water departments supply to households and businesses.Withdrawals of groundwater are expected to rise as the population increases and available sites for surface reservoirs become more limited.
What is artesian basin?
A low-lying district where groundwater is conﬁned under pressure from surrounding layers of rock is called an artesian basin. These basins are often found where an aquifer lies trapped in a syncline, or U-shaped fold, by watertight layers above and below. When a well or rift breaks the surface, the concealed water erupts upward. Artesian springs are usually reliable, unless the underlying aquifer is overtaxed by wells or otherwise drained. The Great Artesian Basin is one of the largest underground water reservoirs in the world.
Importance of Groundwater worldwide
Rural households and public water supplies depend on wells and groundwater; farmers too use groundwater for irrigating crops and even for their animals. Many commercial businesses and industries depend on groundwater for their processes and operations. Many town and city dwellers also drink groundwater. Several counties draw half or more of their public water supplies from groundwater.
Indeed, the largest users of groundwater in the Commonwealth are paper companies in Franklin and WestPoint. Other industries rely on clean groundwaterfor the production of electric power, food, beverages, and material production. Almost 50 billion gallons of groundwater are used each year in Virginia by farms, public water supplies, companies, and families with wells.