Northern India Rapidly Depleting its Groundwater Due to Excessive Irrigation; Major Water Crisis Looms If Trend Continues
15 August 2009
Northern India, probably the most heavily irrigated region in the world, is rapidly depleting its groundwater, according to a new study by researchers from the National Geophysical Research Institute, Hyderabad (CSIR), India; the University of Colorado, Boulder; and the US National Center for Atmospheric Research. If sustained, the trend will lead to a major water crisis in the region, the researchers conclude in a paper to be published in the AGU journal Geophysical Research Letters.
| (A) Rate of change of terrestrial water storage, in cm/yr of water thickness, determined from GRACE gravity solutions. White lines show major rivers. ( B) Same as (A) but after subtracting the naturally occurring water storage variability predicted by the CLM hydrological model. The results in (B) mostly reflect anthropogenically caused groundwater loss. Outlined are the sub-regions used for computing water loss. Tiwari et al. Click to enlarge. |
Combining gravity observations recorded by the GRACE satellite missions with hydrological models to remove natural variability, the team concluded that the region lost groundwater at a rate of 54 ± 9 km3/yr between April, 2002 (the start of the GRACE mission) and June, 2008.
The results for the period suggest a total groundwater extraction rate of about 70% larger than estimates for the mid-1990s. “This dramatic increase shows the dynamic nature of this increasingly critical situation,” they write in their paper. Northern India and its surroundings are home to roughly 600 million people.
This is probably the largest rate of groundwater loss in any comparable-sized region on Earth. Its likely contribution to sea level rise is roughly equivalent to that from melting Alaskan glaciers. This trend, if sustained, will lead to a major water crisis in this region when this non-renewable resource is exhausted.
...The region where GRACE shows decreasing groundwater storage has among the world’s highest population densities. The demand for agricultural products is intense. Groundwater demand is expected to grow many fold in coming years, with increasing agricultural growth and industrialization. Although future climate change is expected to intensify the precipitation and thus increase water availability in this region, evaporation will likely also increase due to the warmer climate. It could thus well be that one of the most populated areas on Earth will eventually be struggling for water. It is of immediate concern to recharge the aquifers of north India, Nepal and Bangladesh through suitable management of surface water for the sustainable availability of water and the preservation of ecosystems.
—Tiwari et al.
GRACE provides monthly, global, gravity field solutions at scales of a few hundred km and greater, in the form of spherical harmonic coefficients. Models remove atmospheric and oceanic contributions. The researchers computed monthly mass changes in southern Asia, which they interpreted in terms of changes in continental water storage.
The gravity field results are equally sensitive to water at all depths: surface water, soil moisture, and groundwater, and include anthropogenic effects. To isolate the anthropogenic contributions, they subtracted monthly water storage estimates predicted by land surface models.
Resources
V. M. Tiwari , J. Wahr and S. Swenson (2009) Dwindling groundwater resources in northern India, from satellite gravity observations. Geophys. Res. Lett., doi: 10.1029/2009GL039401, in press
Tragedy of the Commons...strikes again.
Posted by: ejj | 15 August 2009 at 09:23 AM
A few dams could retain the flow and store enough water from the Hymalayas mountains for irrigation purposes year round.
It may be more of a water management than shortage problem.
Posted by: HarveyD | 16 August 2009 at 07:03 AM
Population control or reduction is the key issue.
Posted by: Peace Hugger | 16 August 2009 at 04:25 PM
Peace Hu
yes but they will suck the whole thing before admitting it, too bad but that's what it is, human race is just out of control.
Posted by: Treehugger | 16 August 2009 at 06:53 PM
I've heard, several times, that the cause of this was the need for much more water by new "superior" rice strains now being grown. Indian farmers were convinced that new higher-yielding rice strains from Western seed companies would bring them more money, which it did. This helped them afford wells and pumps to take water from the ground to supply the additional amounts needed by the new strains. Multiply this by a few hundred thousand farmers and voila, impending water crises.
Posted by: drivin98 | 16 August 2009 at 10:35 PM