Global hotspots mapped out in new water study

Two people stand in front of a giant screen on which a map of the world is projected, with freshwater basin stress identified by colour.
Xander Huggins (right) maps vulnerability in the world’s freshwater basins with the help of co-authors who include his PhD supervisor at UVic, Tom Gleeson (left), an expert in groundwater research.

2022 May – Research led by a UVic PhD candidate has identified 168 water basin “hotspots” that should be prioritized in efforts to achieve future freshwater sustainability for the planet.

Xander Huggins has analyzed freshwater basins around the world to better understand the impact of hydrologic change on human and ecological systems. The research, which was recently published in Nature Communications, identifies the basins that are most at risk to experience societal and ecological impacts due to freshwater stress and storage loss.

“These basins are found on every continent and they represent the epicenters of potential system-wide issues,” says Huggins, who is working on a PhD at both UVic Civil Engineering and the University of Saskatchewan’s Global Institute for Water Security.

“Understanding the potential for social and ecological impacts from freshwater stress and storage loss at the global scale is important in informing prioritization within international sustainability initiatives, such as the UN Sustainable Development Goals.”

The 168 hotspot basins identified encompass more than 1.5 billion people, 17 per cent of global food crop production, 13 per cent of the global gross domestic product, and hundreds of wetlands that have been designated as internationally important.

The research paper notes that there are substantial social and ecological benefits to reducing vulnerability in hotspot basins, which may be achieved through diplomacy, capacity building, and integrated water resources management practices. Some of the most vulnerable basins are those that cross international borders, especially in Eastern Africa and Southern Asia.

In places where water tables are dropping and wells are at risk of running dry, access to groundwater access may intensify social inequalities, as only the wealthy may be able to afford to drill deeper wells. Such conditions may trigger conflict and have implications on international security.

The study used the best available global hydrological, socio-hydrological and eco-hydrological datasets in order to map the basins that are most vulnerable to freshwater stress and storage loss. Huggins says this work presents an alternative approach to guide prioritization of water resource sustainability initiatives, one that is informed by system-wide vulnerability of impacts rather than being guided by water resource trends on their own.

Freshwater stress is defined as the ratio of freshwater withdrawal to streamflow, while freshwater storage is defined as the vertical sum of groundwater, soil moisture, surface water, and snow water equivalent storages. The two are linked as freshwater storage becomes a required source of water during periods when demands exceed supply, though this study was the first to compare the two at the global scale.

Read Hotspots for social and ecological impacts from freshwater stress and storage loss in Nature Communications.

2022May04 AT