More than half of the world’s major lakes and reservoirs dry up. A new study based on satellite imagery has shown that 53% of these water surfaces have decreased significantly since 1992. And yes, it’s partly our fault.
From the Caspian Sea, located between Europe and Asia, to Lake Titicaca in South America. The total loss of water is 22 gigatonnes per year for nearly three decades. In perspective, it’s as if Lake Mead, the largest reservoir in the United States by volume (about 30 km³ of water), has dried up 17 times.
Fangfang Yao, a hydrologist at the University of Virginia and leader of the study, explained that the main causes are global warming and excessive human consumption of food.
Yao and his team they assessed almost 2000 lakes, They make up 95% of all water in the world’s lakes.. they collected 250 thousand images of these surfaces and their surroundings, taken between 1992 and 2020. The material was analyzed with the support of climate and hydrological models.
Lakes dry up in all regions
A study published in the journal Science found that human consumption is drying up lakes such as the Aral Sea in Central Asia and the Dead Sea in the Middle East. While the increase in temperature affects the surfaces to a greater extent in Afghanistan, Egypt and Mongolia. But the drought reaches all regions.
One of the remarkable findings of the study is that these water sources decreases in both the wettest and driest regions of the world.. Decreases have been found in wet tropical lakes of the Amazon, as well as in areas of the Arctic.
The study also highlights that 25% of the world’s population lives in the lake basin, which is on a downward trend. It means that drought directly affects about 2 billion people.
“More than half of the net water loss in natural lakes is due to direct and indirect human impact,” Yao said. Newsweek. Balaji Rajagopalan, co-author of the study, noted that sound governance is urgently needed to address this issue. “It is difficult to revive a lake that is drying up or has already dried up … This is especially important in an increasingly warming world,” he added.
From anxiety to action
This week, the World Meteorological Organization warned of possible global warming. will exceed the temperature limit of 1.5ºC in the next 5 years. The consequences are already affecting the entire planet: spectacular heatwaves, unprecedented droughts and the extinction of various species. But beyond this threshold, experts say, it will be much more difficult to control everything.
There is good news in lake drought research. While most of the world’s lakes dry up, 24% of those surveyed experienced a significant increase in water supplies. Many of them are in uninhabited areas: inland on the Tibetan Plateau and on the great northern plains of North America. Also in regions with new reservoirs, such as the Yangtze, Mekong and Nile river basins.
One of the grown lakes was Sevan, located in Armenia. This is an illustrative case. Since 2000s authorities implement environmental laws on local water extraction. “If human consumption of water is the main driver of lake water depletion, then we can adapt and explore new strategies,” explained Ben Livne, another participant in the study. Here’s a hint on how to get started.
Source: Hiper Textual
