A staggering 180 million people in India face “severe” water scarcity all year round, according to a research paper published in the latest edition of Science Advances , which depicts, in its maps, Andhra Pradesh, Telangana, Karnataka, Gujarat, Rajasthan and Haryana as being among the worst affected.
Water scarcity has been “underestimated” by previous studies, as also the number of people affected by the deficit, says the paper titled “Four billion people facing severe water scarcity”. This could be because the studies assessed water scarcity at very large geographical units and vast temporal spans (annually rather than on a monthly basis).
Globally, four billion people — or 66 per cent of the population — live with severe water scarcity for at least a part of the year. And of these, one billion live in India and 0.9 billion live in China. This “implies that the situation is worse than suggested by previous studies, which give estimates between 1.7 and 3.1 billion” worldwide.
Needless to say, the victims of water over-extraction are the “users themselves, who increasingly suffer from water shortages during droughts, resulting in reduced harvests and loss of income for farmers, threatening the livelihoods of whole communities”, says the paper.
Implications for India There are specific geographical areas where the water crisis is particularly acute. For instance, in the Ganges basin, blue water — or fresh water (surface water and aquifers) — is being consumed in a “countercyclical” fashion, with “water consumption being highest when water availability is lowest”.
So what do these findings mean for India where irrigated area under cultivation accounts for a little less than half the cultivated area? “There is no doubt that there could be better water management, especially through water harvesting, and that ‘more crop per drop’ can be achieved, for instance through better irrigation technology,” says economist Venkatesh Athreya. “However, discussions on water do not adequately deal with the growing inequities in consumption, characterised by huge concessions to big capital, guaranteeing them water on demand and at low cost. On the other hand, small and marginal farmers, who produce a substantial proportion of our foodgrain, have rather limited access to water and often at high cost.”
Researchers looked at blue water scarcity on a per-month basis dividing up the area according to specific grid cells. Water scarcity was calculated as the ratio of the blue water “footprint” (consumption) in a grid cell to the total blue water availability in the cell. They classified water scarcity as low, moderate, significant and severe.
Using crop maps, data on growing periods, estimated irrigation requirements, and data on actual irrigation, researchers calculated the blue water footprint of crop production.
“Meeting humanity’s increasing demand for fresh water and protecting ecosystems at the same time, thus maintaining blue water footprints within maximum sustainable levels per catchment, will be one of the most difficult and important challenges of this century,” the paper concludes. And a vital strategy to reduce blue water consumption would be to increase the productivity of rain-fed agriculture, it adds.
divya.gandhi@thehindu.co.in
