iii. Groundwater
A part of the rainwater percolates in the rocks and the soils and is available as groundwater.
Groundwater is vital to human welfare and development, and in many countries, it is the principal source of water for drinking, irrigation, and industry.
As a core component of the hydrological cycle, groundwater is also critical to sustaining many aquatic and terrestrial ecosystems.
However, various issues have emerged regarding its sustainable use and management especially in the present scenario when there are severe water shortages around the world.
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Changes In Groundwater
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- Depletion of groundwater resources– Dynamic Ground Water Resource Assessment Report 2022 states that the total annual groundwater recharge is 437.60 Billion Cubic Meters (BCM) and the annual groundwater extraction is 239.16 BCM.
- Agriculture -accounts for nearly 90% of groundwater withdrawals. Practices such as power subsidies for irrigation, MSP for water-intensive crops such as rice, green revolution, and lack of regulations have expedited its extraction.
- Use for drinking and cooking purposes in water-stressed areas
- Deforestation, urbanization, metalled road construction, etc has led to a decline in the percolation of water underground and hence the recharge of aquifers.
- Industries, the second-largest users of groundwater i.e approx.5%, likewise rely on groundwater to meet their water requirements.
- Virtual water trade plays a major role in depleting groundwater.
- Overexploitation of existing resources. Out of the country’s total of 7089 assessment units, 1006 units have been labeled as over-exploited.
- Pollution with the addition of contaminants such as arsenic, fluoride, iron, and other heavy metals is caused due to human activity, such as residential sewage, agricultural practices, industrial effluents, etc.
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Consequences
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- The hydrological cycle is interrupted as groundwater acts as its major component
- Water stress and insecurity are already on the rise and depleting groundwater resources amplify this many folds. The rising population and increased urbanization also increase the demand for domestic water.
- Threat to food security as more than 60% of irrigation in agriculture is met by groundwater in India. This especially has risen after the green revolution.
- Increased incidents of droughts around the world.
- Health issues, such as groundwater contamination such as arsenic and fluoride cause cancer and skin problems.
- Health also impacts Human Capital formation because of high mortality and lifelong diseases among children and adults.
- The economy of the country is also impacted due to the dependence of many industries on groundwater
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