Groundwater sustainability in India through nonrice-dominated cropping pattern

Area of Science:

• Hydrology
• Agricultural Science
• Climate Change Science

Background:

• Over-exploitation of groundwater for irrigation has led to rapid depletion in north India, threatening food and water security.
• The impact of changing cropping patterns on groundwater savings under a warming climate is not well understood.

Purpose of the Study:

• To investigate the potential of altering cropping patterns for groundwater sustainability in north India.
• To quantify groundwater savings from optimized crop switching scenarios under observed and projected climate conditions.

Main Methods:

• Utilized satellite and model-based estimates to assess groundwater depletion from 2002-2022.
• Developed optimized crop switching scenarios considering nutritional needs, farmer profits, and crop production.
• Analyzed groundwater savings under current and projected future climate scenarios (1.5-3 °C warming).

Main Results:

• North India lost approximately 336-297 km³ of groundwater between 2002-2022.
• Crop switching scenarios (CSI and CSII) could save 45-91 km³ of groundwater under observed climate.
• Replacing 37% of rice area (CSII) could recover 61-108 km³ of groundwater under future warming.

Conclusions:

• Altering current rice-dominated cropping systems offers a viable solution for groundwater sustainability in north India.
• Crop switching provides substantial groundwater savings under both current and projected future warming climates.
• The benefits of crop switching for groundwater are amplified during prolonged dry periods under a warming climate.