Vulnerable flows the Indus water

Bleak basin

The Indus basin comprising five major rivers in north India and Pakistan is the world’s most vulnerable water zone where the demand for fresh water will outweigh supply in future, says a new study.

Scientists from Europe, America and Asia looked at the importance and vulnerability of river basins by not merely examining the survival quotient of glaciers but also checking if water supply in a basin can match up with increased demand and climate change pressure in future.

The team studied the current importance and future risk factors of 78 water towers — a unit consisting of a river basin and snowy mountains that supply water in that basin — all over the world to find out the conservation requirements of such towers.

Strikingly, the researchers found that Indus, which is globally the most important water tower, has also been the most vulnerable one.

Factors ranging from political tension between its riparian countries (Pakistan, India, China and Afghanistan) to a 50% population growth by 2050 from the existing 206 million and an eight-fold projected rise in the GDP contribute to the risks.

Climate change factors also add to the vulnerability. The temperature of the Indus water tower is projected to increase by 1.9 degrees Celsius between 2000 and 2050, compared to 1.8 degrees Celsius in the downstream section, whereas the average annual rainfall in the in the same area is projected to increase by 0.2%, compared to 1.4% downstream.

“Due to the expected strong growth in population and economic development, the demand for fresh water will rise exponentially. Combined with increased climate change pressure on the Indus headwaters, an already high baseline water stress and limited government effectiveness, it is uncertain whether the basin can fulfil its water tower role within its environmental boundaries. It is unlikely that the Indus water tower can sustain this pressure,” the scientists reported in Nature on Monday.

The Indus, however, is not a standalone case. All important water towers in Asia, like the Amu Darya, Tigris, Ganges-Brahmaputra and Tarim system, are also highly vulnerable. For each tower, the researchers assessed its vulnerability related to water stress, governance, hydro-political tension and future climatic and socio-economic changes. They concluded that the most important water towers are the most vulnerable, impacting 1.9 billion people.

The vulnerability of the Ganges-Brahmaputra basin was less because it received lot of monsoon rainfall, reducing the basin’s dependence on glacial waters, said Anil Kulkarni, a distinguished scientist at the Indian Institute of Science, Bengaluru and one of the co-authors of the paper.

“Climate change, in combination with population growth, urbanisation and economic and infrastructural developments, is likely to exacerbate the impact of natural hazards and further increase the vulnerability of these water towers. Immediate action is required to safeguard the future of the world’s most important and vulnerable water towers,” the scientists reported.