Our water cycle diagrams give a false impression of water security

According to a new analysis by an international team of hydrology experts, images of the Earth's water cycle used in education and research around the world urgently need to be updated. day to show the effects of human interference.

The researchers argue that leaving human beings irrelevant, contributes to a fundamental lack of awareness of the relationship between men and water and to water on Earth – and a false sense of security as to the future availability of this essential and rare resource.

The team has developed a new set of diagrams to better understand how our 21st century water cycle works. These new diagrams show human interference in almost every part of the cycle.

The study, published in Nature Geoscience, with an additional commentary in Nature, was conducted by a large team of experts from Brigham Young University and Michigan State University in the United States and the University of Birmingham in the United Kingdom, as well as partners in the United States, France, Canada, Switzerland and Germany. Sweden.

It shows that, of a sample of more than 450 water cycle diagrams in textbooks, scientific literature and online, 85% showed no human interaction with the water cycle. and only 2% of the images attempted to link the cycle with climate change or water pollution.

In addition, almost all of the examples studied described lush landscapes, temperate climates and abundant fresh water, usually with only one watershed.

The researchers argue that it is urgent to challenge this misrepresentation and promote a more precise and sophisticated understanding of the cycle and its functioning in the 21st century. This is essential for the company to be able to find global solutions to the global water crisis.

"The water cycle diagram is a central icon of hydro science, but falsely describing the influence of man on this cycle decreases our awareness of the global crisis of the world. Water is looming, "says Professor David Hannah, UNESCO Chair in Water Science at the University of Birmingham. .

"Leaving aside climate change, human consumption and changes in land use, we are actually creating large gaps in understanding and perception among the public and among some scientists."

The new diagrams elaborated by the team present a more complex picture including elements such as glacier meltwater, damage caused by floods caused by land-use changes, pollution and the rise in sea level.

Professor Stefan Krause, director of the Birmingham Water Council, said: "For the first time, the new water cycle diagram reflects the importance not only of water quantities but also of water. quality of water and pollution as essential criteria for assessing water resources ".

Professor Ben Abbott, of Brigham Young University, is the lead author of the paper: "Every science diagram involves tradeoffs and distortions, but what we discovered with the water cycle was the widespread exclusion of a central concept.You can not understand water in the twenty-first century without including humans. "

"Other scientific disciplines have done a good job in describing how humans now dominate many aspects of the Earth system.It is difficult to find a carbon or nitrogen cycle chart that does not show the neither factories nor fertilizers.However, our water cycle drawings are stuck in the 17th century. "

"Better water cycle drawings alone will not solve the global water crisis alone, but they could better explain how much water use at the global level. local and climate change have global consequences. "