Groundwater Recharge

GS Paper I Geography

Context:

According to a report by Central Ground Water Board (CGWB), Delhi recharged more groundwater than it extracted in FY 2021-22.

This is the first time since at least 2009-2010 that Delhi’s recharge is more than its extraction.
Compared to 2020-21, the number of “safe” tehsils in Delhi has gone up from three to four, while the number of “overexploited” tehsils has dropped from 17 to 15.
However, Delhi is still “critical” in terms of groundwater extraction.

About Groundwater:

Groundwater is the water that is present beneath the Earth’s surface within the spaces and fractures of rocks and soil.
It is a vital component of the Earth’s water cycle and plays a crucial role in supporting ecosystems.

Groundwater Exploitation

States such as Punjab, Rajasthan and Haryana are exploiting groundwater more than the quantity of its recharge.
This overexploitation of groundwater is likely to be the source of geogenic contaminants such as arsenic and fluoride.

India’s Groundwater

India has 4 per cent of global water resources for its use in spite of having 17 percent of the world population.
- There are wide spatial and temporal variations in the distribution of water.
Groundwater is the backbone of India’s agriculture and drinking water security.
- Contribution of groundwater in agriculture is about 62 per cent, 85 per cent in rural water supply and 50 per cent in urban water supply, respectively.
Main Source: The main source of groundwater resources is rainfall which contributes to nearly 61 per cent of total annual groundwater recharge according to a Central Groundwater Board (CGWB) report ‘National Compilation on Dynamic Groundwater Resources of India, 2022’
India’s per capita availability of water has touched the water stressed benchmark, and is likely to reach a water scarce scenario by 2050.

Recharge of groundwater: Recharge of groundwater depends on the type of rock formation in a place.
- For example, porous formations (such as alluvial formation) in the Indo-Ganga-Brahmaputra basin have high specific yields and are good repositories of groundwater.

Ways to Improve Groundwater level:

The groundwater level can be increased by two means — artificial recharges and rainwater harvesting.
- Artificial recharge: It is a process that increases infiltration either through faster rates or due to availability of source water in a longer time duration.
- Rainwater Harvesting: Collect and store rainwater for direct use or recharge purposes, reducing the reliance on groundwater for certain applications.

News Source: The Hindubusinessline