Groundwater Sources

Groundwater sources are beneath the land surface and include springs and wells.When rain falls to the ground, water flows along the land to streams or lakes, evaporates into the atmosphere, is taken up by plants, and seeps into the ground, as depicted in the hydrologic cycle.The water stored underground between soil particles and rocks is groundwater.

The country’s total replenishable groundwater resources are around 432 cubic kilometers.
Water is stored underground between soil particles and rocks, forming groundwater..
In the river basins of the northwestern area and sections of south India, groundwater utilization is relatively high.
India also relies heavily on groundwater resources, which account for more than half of all irrigated land and serve 20 million tube wells.
To conserve river waters and improve groundwater recharging, India has built about 5,000 major or medium dams, barrages, and other structures.

Groundwater is an available aquifer below the water table.
Water present in pore spaces of permeable rocks below the surface is called groundwater.
All the pores of rocks filled with water are called the saturation water zone.

Aquifer:

Aquifers are large pools or stores house of groundwater.
There are two types of Aquifers:

Unconfined Aquifer
- Usually, exposure to the Surface.
Confined Aquifer
- It exists between two impermeable rocks( rocks that water does not pass).
- A well or tube well extracts water from a confined aquifer by breaking the impermeable rocks.

What is the Status of Groundwater in India?

India is the largest user of groundwater with a fourth of the total global withdrawal. Indian cities cater to about 48% of its water supply from groundwater.
There are over 4,400 statutory towns and cities in India, with around 400 million residents, which will increase by up to 300 million by 2050.

What are the Sources of Groundwater?

Rainwater, rivers, and Ponds water seeps through soils and filled the empty space and cracks below the ground.
The process of seeping water from the surface into the ground is called infiltration.
Groundwater gets recharged by the infiltration process.

Depletion of Water table

Reasons for Groundwater depletion:

Increase in population
Industrial Activities
Agriculture activities
Low rainfall
Deforestation
The decrease in effective areas of seepage of water.

Groundwater Pollution:

Anthropogenic activities and geogenic sources largely compromise the quality.
This further raises the level of contamination as heavy metal concentration in the earth’s crust is higher than on the surface.
Additionally, surface water pollution also affects groundwater quality as pollutants at the water surface percolate through the layers of the land, contaminating groundwater, and may even alter the soil structure in case of oil leakages or spillage.

Climate Change:

The problems groundwater faces in India feeds into worsening the climate crisis, which further deepens the distress associated with groundwater availability.
Disturbances in the hydrological cycle causing long spells of floods and droughts adversely affect the quality and quantity of groundwater.
- For example, flood events risk increased runoff of chemicals and biotic contaminants into groundwater.

Groundwater usage Patterns in India

Irrigation is by far the biggest consumer of India’s water reserves, accounting for 78 percent of total water reserves, followed by the household sector(6%), and the industrial sector (5%).
In both urban and rural India, groundwater is a key supply of drinking water. Groundwater reserves provide 45 percent of total irrigation and 80 percent of household water.
In some states, overuse of groundwater has led to a major scarcity of water.