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Local strategies needed to sustain precious groundwater sources used for agriculture

by CIFAR Mar 5 / 13

Groundwater is a life-sustaining resource for both humans and the environment, but scientists are warning that precious groundwater aquifers around the world are being depleted at unsustainable rates.

In a review article about groundwater depletion published in the journal Nature Geoscience, CIFAR Global Scholar Tom Gleeson and his colleague show that irrigation of agricultural land is the main reason for unsustainable groundwater use, especially in parts of India, China and the United States, and stress the urgent need for region-level strategies to prevent its depletion.

This review paper was inspired by his important work in developing the “groundwater footprint,” which he and his team reported in a paper last August. That research received world attention and was listed as one of DISCOVER magazine’s 100 Top Science Stories of 2012.

“After completing the study on groundwater footprint, I saw that there was a need to compare the different rates of global groundwater depletion, examine the causes of groundwater depletion and search for solutions,” says Gleeson. “Sustaining groundwater into the future will be critical for our food production and security. We hope that water scientists, water managers and policy makers pay attention to our findings.”

In the review article, the researchers argue that there is no single solution for groundwater management. Rather, the characteristics of local regions, such as climate, social and economic conditions need to be taken into account in order to develop sustainable solutions. For instance, they propose that farmers in regions with sufficient surface water, like rivers and lakes, could use it in combination with groundwater to irrigate their land. They also note a number of new innovations underway that others could learn from. In India, a promising strategy is being investigated to use existing canal networks to artificially recharge groundwater reservoirs. In Texas, new regulation has given the water development board the authority to set long-term goals about how groundwater should be used, and they employ groundwater models to help them to predict sustainable rates for extracting the water.

Gleeson is now working on detailed groundwater footprints for India and the United States in collaboration with the UN Food and Agriculture Organization.