Four billion people worldwide are affected by severe water scarcity for at least one month every year, says Arjen Hoekstra, a professor of water management at the University of Twente. The professor published the findings in the journal Science Advances, showing that the figure was higher than previously thought.

Hoekstra started the research in 2010 with the help of Mesfin Mekonnen, an Ethiopian researcher at the University of Twente. Through modelling and gathering data about climate, land use, soils, crop growth, irrigation, population densities and industry, they determined the population’s monthly water consumption and compared to the amount of water allotted for monthly use.

People in Mexico, western US, northern and southern Africa, southern Europe, the Middle East, China, Australia and India feel the effects of water scarcity more than anyone in the world. The water supplies are still well elsewhere but the risk still exists.

“Groundwater levels are falling, lakes are drying up, less water is flowing in rivers, and water supplies for industry and farmers are threatened,” Hoekstra notes. “In this research, we established the maximum sustainable ‘water footprint’ for every location on earth, and then looked at actual water consumption. If the latter is much greater than what is sustainable, then there can be said to be severe water scarcity.”


Flickr/UK Department for International Development

Flickr/UK Department for International Development

The team says that previous investigations about water scarcity focused only on the scarcity on an annual basis and were limited to the largest river basins. Scientists have also thought that only two to three billion people were affected by the scarcity.

Hoekstra says that the World Economic Forum ranked the world water crisis in the top three of the global problems, together with climate change and terrorism. The increasing global population, changing consumer habits and climate change play a huge part in deteriorating sources and quality of water.

Hoekstra’s team will continue the next step in their research, which will provide further information about the water scarcity problem. After analysing new data, the researchers hope to come up with effective solutions to combat this.