Groundwater Depletion In India

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According to recent study, the Groundwater depletion may reduce winter cropping intensity by 20% in India by 2025.

• India’s three main irrigation types on winter cropped areas: dug wells, tube wells, canals.

Key Findings

• With current groundwater depletion trends,  cropping intensity may decrease by 20 percent nationwide and by 68 percent in groundwater depleted regions.
  • Cropping intensity refers to raising of a number of crops from the same field during one agricultural year; it can be expressed through a formula. 
    • Cropping Intensity = Gross Cropped Area / Net Sown Area x 100.
• 13 percent of villages in which farmers plant a winter crop are located in critically water depleted regions.
• Switching to canal irrigation has limited adaptation potential as that would lead to 7 percent decline in the cropping intensity.

Groundwater Depletion in India 

• India is the world’s second-largest producer of wheat, and rice and is home to more than 600 million farmers. 
• The country has achieved impressive food-production gains since the 1960s, due  to an increased reliance on irrigation wells, which allowed Indian farmers to expand production into the mostly dry winter and summer seasons 
  • These gains have come at a cost with severe groundwater depletion, the cropping intensity or the amount of land planted in the winter season may decrease by up to 20% by 2025
  • The country that produces 10% of the world’s crops is now the world’s largest consumer of groundwater, and aquifers are rapidly becoming depleted across much of India. 

Causes of Groundwater Depletion

•  Green Revolution: In the green revolution era, policy-supported environment led to a large increase in rice cultivation in northwestern India mainly in Punjab and Haryana which are ecologically less suitable for rice cultivation due to predominantly light soils.”
  • This policy-supported intensive agriculture led to unsustainable groundwater use for irrigation and in turn groundwater scarcity. 
• Poor infrastructure: There are enough groundwater resources supported with higher monsoon rainfall in eastern Indian states like Bihar. But due to lack of enough irrigation infrastructure, farmers are not able to make use of natural resources there.

• Increased demand: Increased demand for water for domestic, industrial and agricultural needs and limited surface water resources lead to the over-exploitation of groundwater resources.
• Inadequate regulation of groundwater laws encourages the exhaustion of groundwater resources without any penalty.

Government Initiatives 

• Use of tensiometer: The tensiometer gives visual information about the availability of soil moisture conditions. Irrigating the field based on this information will help conserve groundwater.
  • The tensiometer is 2–3 feet long and has a ceramic cup containing numerous tiny pores at the bottom. It is inserted up to 8 inches into the soil, which is beyond the root zone of rice. The water inside the tensiometer reaches equilibrium with soil moisture, and rises or falls depending on the amount of moisture in the soil.

• Atal Bhujal Yojana: It  is a Central Sector Scheme for facilitating sustainable groundwater management with an outlay of INR 6000 crore
  • The scheme lays emphasis on community participation and demand side interventions for sustainable groundwater management in identified water stressed areas in seven States of the country. 
  • The scheme also envisages improved source sustainability for Jal Jeevan Mission, positive contribution to the Government’s goal of ‘doubling farmers income’ and inculcating behavioral changes in the community to facilitate optimal water use.
• Promoting Rainwater Harvesting and Precision Agriculture. 

Way Forward 

• Farmers in the regions where groundwater depletion has already occurred should consider cultivating less water-intensive crops, use better irrigation technologies and irrigate crops only when necessary.
• Adoption of water-saving technologies like a sprinkler, drip irrigation and maybe switching to less water-intensive crops may help use the limited groundwater resources more effectively

• We need coordinated efforts to solve this water availability and food security issue, which should be supported by science-led policy decisions on what strategies and technology solutions to scale out to improve irrigation efficiency.
• Indian government officials have suggested that switching from groundwater-depleting wells to irrigation canals, which divert surface water from lakes and rivers, is one way to overcome projected shortfalls.

Source :TH