Global threats to human water security and river biodiversity is the title of a new study that points out that almost 80% of the world’s population are exposed to some risk of insecure freshwater resources (published in Nature 467, 555-561 (30 September 2010) | doi:10.1038/nature09440). The researchers created a global raster plotting the security level of water resources based on an index of water threats which is discussed in their paper.
Much of the threats in wealthier countries can be counteracted with technology, which explains much less actual insecurity in these countries – but therefore puts biodiversity at risk and resulting in a high price for an inevitable resource of human life.
Talking to BBC News Peter McIntyre from the University of Wisconsin, one of the scientists involved in the study, puts it this way:
“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.” (Source: BBC)
The unaltered stress level of global freshwater resources as published in the study is presented in this map (Source: Nature):
Accompanied by the map of biodiversity, this gives an interesting insight to the impacts on biodiversity. The impact on human population remains less shown in this depiction but is another crucial issue of the paper. As mentioned before, 80% of the world population are exposed to threatened water resources. By applying their map to the gridded-cartogram technique, the whole impact of these threatened water resources on the population becomes apparent. The 80% at risk become visible, as the map transformation preserves the geographical reference of the underlying grid. The emerging picture is going along quite well with the findings of the study and thus adds another interesting perspective on the issue of threatened water resources in the most populated regions in the world. All data from the study is available on http://www.riverthreat.net/data.html and we used that data to reproject the key maps of the study.
This map shows the “natural” picture of the human water security threat level from the study:
When taking the investments on water technology into account, this picture changes considerably, as the next map shows:
But use of technology often goes along with risks and damage for nature, as the map of river biodiversity at risk shows:
Benefiting the population, damaging biodiversity, use of technology to exploit water sources may be seen controversial. Where it is mostly used in relation to the population shows the last map:
All maps are based on source data from the Rivers at Risk website and build upon the related study in Nature. The method used to reproject these maps is described in various pages of this website.