New study identifies global water scarcity hotspots and reasons for their existence

Global freshwater resources are vital to humanity and ecosystems, yet billions around the globe face water scarcity issues on a monthly basis. A team of scientists from Utrecht University in collaboration with National Geographic Society has identified global water scarcity hotspots around the world. In these regions long-term overuse of freshwater resources leads to the threat of freshwater depletion and societal impacts. The findings, published in scientific journal Environmental Research Letters, show how different pressures on the water system have led to unsustainable water use and could help those working in water management with finding sustainable solutions to these pressing global challenges.

The work, led by Myrthe Leijnse, used state-of-the-art global hydrological modelling to find the locations of the global water scarcity hotspots. The following countries and regions can, for a variety of reasons, be considered as water scarcity hotspots: the Arabian Peninsula, Central Chile, Spain, the Murray-Darling Basin (Australia), Japan, the North China Plain, the Central Valley (California), the US High Plains, the Sudanese White Nile Basin, the Nile Delta, Italy, Greece, Türkiye, the Indus and Ganges River Basins, Coastal Peru, Iran, Mexico, Java, Vietnam and Thailand.

Behind every hotspot a complex story on the origin and consequences of water scarcity is hiding

Freshwater resources

To independently benchmark these modelling efforts, the Utrecht team examined over 300 local case studies. The study reveals what local policy actions have been taken at hotspots that positively or negatively affect the freshwater resources. Leijnse identified 5 major reasons for the occurrence and impact of hotspots:

1. Hydroclimatic change and population growth as most important drivers of water scarcity at the majority of hotspots;
2. Agricultural and domestic water use are key pressures on the water system affecting water quality and quantity;
3. Increasing trends in these major drivers and pressures over the last decades that indicate a potential continuation of decreasing water quality and quantity at the hotspots in the future if no appropriate action is taken by local authorities;
4. The most important impacts on society and the environment at the hotspots include damage to ecosystems, conflicts, migration, and a reduced agricultural production;
5. Policy actions taken at the hotspots currently comprise of a variety of positive contributions, such as increased storage capacity, water treatment and water transfer, while other policies, including unregulated water use and unfair water rights systems, negatively affect water scarcity at hotspots.

Sustainable solutions for policymakers

Commenting on the importance of the study, Myrthe Leijnse stated, “During our literature research, it struck me that behind every hotspot a complex story on the origin and consequences of water scarcity is hiding, and that people deal very differently with their water scarcity problems everywhere. The new insights of our research can help to transfer knowledge and solutions between different hotspots. This would help local policymakers deriving sustainable solutions to reduce or alleviate local water scarcity. This is especially relevant as both climate change and population growth are expected to put more pressure on most hotspots and thus increase the challenge they are facing.”

As a next step Utrecht University and National Geographic Society are planning to use their insights to equip policy makers with more detailed information on the versatility of water scarcity and to evaluate potential strategies to address this critical global challenge.

Article

Myrthe Leijnse, Marc F P Bierkens, Kim H M Gommans, Daisy Lin, Alex Tait and Niko Wanders, ‘Key drivers and pressures of global water scarcity hotspots’, Environmental Research Letters, https://doi.org/10.1088/1748-9326/ad3c54