Water map shows billions at risk of ‘water insecurity’

BBC 02 October

About 80% of the world’s population lives in areas where the fresh water supply is not secure, according to a new global analysis. Researchers compiled a composite index of “water threats” that includes issues such as scarcity and pollution. The most severe threat category encompasses 3.4 billion people. Writing in the journal Nature, they say that in western countries, conserving water for people through reservoirs and dams works for people, but not nature.

They urge developing countries not to follow the same path. Instead, they say governments should to invest in water management strategies that combine infrastructure with “natural” options such as safeguarding watersheds, wetlands and flood plains.

The analysis is a global snapshot, and the research team suggests more people are likely to encounter more severe stress on their water supply in the coming decades, as the climate changes and the human population continues to grow.

They have taken data on a variety of different threats, used models of threats where data is scarce, and used expert assessment to combine the various individual threats into a composite index.

The result is a map that plots the composite threat to human water security and to biodiversity in squares 50km by 50km (30 miles by 30 miles) across the world.

29 September 2010 Last updated at 17:01 GMT Share this pageFacebookTwitter ShareEmail Print Water map shows billions at risk of ‘water insecurity’By Richard Black Environment correspondent, BBC News The study maps water availability and quality down to the regional level About 80% of the world’s population lives in areas where the fresh water supply is not secure, according to a new global analysis.

Researchers compiled a composite index of “water threats” that includes issues such as scarcity and pollution. The most severe threat category encompasses 3.4 billion people. Writing in the journal Nature, they say that in western countries, conserving water for people through reservoirs and dams works for people, but not nature.

They urge developing countries not to follow the same path. Continue reading the main story “ Start Quote What we’re able to outline is a planet-wide pattern of threat” End Quote Charles Vorosmarty City College of New York Instead, they say governments should to invest in water management strategies that combine infrastructure with “natural” options such as safeguarding watersheds, wetlands and flood plains.

The analysis is a global snapshot, and the research team suggests more people are likely to encounter more severe stress on their water supply in the coming decades, as the climate changes and the human population continues to grow. They have taken data on a variety of different threats, used models of threats where data is scarce, and used expert assessment to combine the various individual threats into a composite index. The result is a map that plots the composite threat to human water security and to biodiversity in squares 50km by 50km (30 miles by 30 miles) across the world. Changing pictures “What we’ve done is to take a very dispassionate look at the facts on the ground - what is going on with respect to humanity’s water security and what the infrastructure that’s been thrown at this problem does to the natural world,” said study leader Charles Vorosmarty from the City College of New York.

“What we’re able to outline is a planet-wide pattern of threat, despite the trillions of dollars worth of engineering palliatives that have totally reconfigured the threat landscape.”

Those “trillions of dollars” are represented by the dams, canals, aqueducts, and pipelines that have been used throughout the developed world to safeguard drinking water supplies. Their impact on the global picture is striking. Looking at the “raw threats” to people’s water security - the “natural” picture - much of western Europe and North America appears to be under high stress.

However, when the impact of the infrastructure that distributes and conserves water is added in - the “managed” picture - most of the serious threat disappears from these regions.

Africa, however, moves in the opposite direction. “The problem is, we know that a large proportion of the world’s population cannot afford these investments,” said Peter McIntyre from the University of Wisconsin, another of the researchers involved.

“In fact we show them benefiting less than a billion people, so we’re already excluding a large majority of the world’s population,” he told BBC News.

“But even in rich parts of the world, it’s not a sensible way to proceed. We could continue to build more dams and exploit deeper and deeper aquifers; but even if you can afford it, it’s not a cost-effective way of doing things.”

According to this analysis, and others, the way water has been managed in the west has left a significant legacy of issues for nature. Whereas Western Europe and the US emerge from this analysis with good scores on water stress facing their citizens, wildlife there that depends on water is much less secure, it concludes.

Concrete realities One concept advocated by development organisations nowadays is integrated water management, where the needs of all users are taken into account and where natural features are integrated with human engineering.

One widely-cited example concerns the watersheds that supply New York, in the Catskill Mountains and elsewhere around the city.

Water from these areas historically needed no filtering. That threatened to change in the 1990s, due to agricultural pollution and other issues.