A recent study revealed a new threat to about 1.9 billion people who depend on meltwater coming from glaciers and mountain basins that cover vast areas of land all over the world to meet their water needs.
The study, published in Nature scientific journal on Monday, describes these mountain basins as natural “water towers,” which researchers say are experiencing significant degradation under the pressures caused by climate change and several political, social, and economic factors.
Compared to the plain region, a natural water tower generates seasonally a high runoff of rainwater, as a result of precipitation and then delaying its release by storing it in snow and glaciers (due to low temperatures at high altitudes) and in small lakes in these towers.
The 32-member research team from different international universities led by the Dutch Utrecht University, has identified 78 units of water towers worldwide. The study defines a “water tower unit” as the intersection between a major river basin and the mountains that supply it with water.
Using several indicators, such as precipitation, the size of glacier, the snow cover, and the rates of demand for this water, whether for irrigation, industry, or domestic use, the researchers were able to assess the sensitivity of these units to climate change as well as political and social factors.
Walter Immerzeel, professor of mountain hydrology at the University of Utrecht and lead author of the study, told Daily News Egypt that his research team has for the first time categorised these units according to their importance for neighbouring lowland societies, as well as their degree of exposure to future environmental, social, and economic factors.
These factors threaten the water resources on which the 1.9 billion people who live in these regions depend, nearly a quarter of the world’s population. These factors included political tensions, climate change, population changes, and GDP rates.
“Mountains are vital to the Earth’s water system, and the most important mountain ranges on Earth are most vulnerable to future changes, so preserving natural water towers is necessary to protect mountain ecosystems and their inhabitants, and ensure water, food and energy security for a quarter of the world’s population at one time,” Immerzeel added.
According to the findings of the study, the area of the upper Indus River Basin – which consists of vast areas of the Himalayas that cover parts of Afghanistan, China, India, and Pakistan – is the most important water tower unit, and it is also the weakest due to the large population growth in one of the world’s most densely populated areas, in addition to projected economic growth and increased pressure from climate change.
The water towers of the Andes, the Rocky Mountains of the Americas, the European Alps, and the mountains of the Ganges basin in Asia also face the same challenges.
Therefore, the study stresses the need to develop international policies and strategies to protect these distinct ecosystems from the impacts of climate change and various political and social factors.