SciDev.Net

Extreme population growth in the basins over the last century has put pressure on the region's water resources

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[NEW DELHI] Water resources in three of South Asia's largest river basins are highly vulnerable, with millions of people at risk of increasing water scarcity, a new report has found.

The report — jointly released by the UN Environment Programme and the Asian Institute of Technology — studied the Ganges-Brahmaputra-Meghna (GBM), Indus and Helmand river basins, all of which span multiple countries within the region.

It lists overexploitation, climate change, and inadequate distribution and use of water resources among the key threats to the three basins, calling for "a unique mix of policy interventions and preferred routes for future water resources development" to tackle these challenges.

Jinhua Zhang, regional coordinator at the UNEP Division of Early Warning & Assessment told SciDev.Net that countries should cooperate more to improve how water resources are managed — particularly to control pollution and improve efficiency — to help stop further damage to these rivers.

The report assigned each river basin a vulnerability index, based on resources stress, development pressure, ecological health and management challenges. The GBM basin is most vulnerable, but water resource systems in the Helmand and Indus basins are also highly vulnerable.

Extreme population growth in the basins over the last century has put pressure on the region's water resources, while around two-thirds of the Himalayan glaciers that feed the basins are receding. Additionally, groundwater levels in the GBM and Indus basins are declining at a rate of two to four metres per year due to intense pumping.

In India alone the amount of water per head has decreased from 4,000 to 1,869 cubic metres in the last twenty years.

Zhang told SciDev.Net that further research is needed to identify the supply of glacial melt for a given area, the amount of wastewater generated by industry, and strategies for water treatment.

"The per capita availability of freshwater is declining, and contaminated water remains the greatest single environmental cause of human illness and death," he says.  

Improving our knowledge of the vulnerability of freshwater resources "is therefore essential so that policymakers can manage this vital resource for the benefit of their people, their economies and the environment,'' says Zhang.

The report was released this month (9 February) and is the first of a series. UNEP is doing similar assessments in North East Asia and South East Asia.

Link to full report[2.28MB]