More than half of the adults lakes 100 percent of the world is losing water Climate change is exacerbating what intensified human consumption has already begun. These large water reserves, on which a large part of the world’s population depend, are decreasing, and with this, the possibility of relying on this resource in the long run also decreases.
This was prompted by an international group of scientists in an article published in the journal ‘Science’, thanks to an extensive study of collecting historical data via satellite. over the last three decades they have succeeded in reconstructing the volume of the world’s great lakes.
“This is the first comprehensive assessment of global trends and drivers of lake water volume changes,” said lead author Fangfang Yao of the University of Colorado Boulder’s Environmental Sciences Research Institute (CIRES).
To carry out this study, a research team from universities in the states of Colorado and Kansas (USA), France and Saudi Arabia developed a new technique. measures changes in water levels in the world’s nearly 2,000 major lakes and reservoirs. An amount representing at least 92% of all stored water on the planet
From them, 12 of them are Spanish reservoirs: Iznajar, Puente Nuevo (Andalusia), Serena, Cíjara, Valdecanas, Alcántara (Extremadura), Almendra, Ricobayo (Castilla y León), Yesa (Navarra), Buendía, Alarcón (Cuenca) and Mequinenza (Aragón). The study shows that of the reservoirs studied in Spain, 8 have dried up, three show no significant trend and only one, Alarcón, is filling up.
With data collected between 1992 and 2020, the researchers designed a model that can measure and observe water storage trends in these lakes. In particular, the team recovered satellite photos of 1,972 of the largest lakes on Earth.
They also gathered information about water level from nine altimeters attached to satellites and compared that data with historical information about its flow, reducing uncertainty. Meanwhile, for lakes with no historical records, the team used water measurements made by other methods in recent years.
This is how they came to the conclusion 53% of the world’s lakes have experienced a decrease in their flow. This is the equivalent loss to the entire runoff of Lake Meads, the largest reservoir in the United States. This negative trend is repeated in both arid and humid regions, indicating that the drought problem is much more common than previously thought.
Also, as seen in reservoirs, it is not a problem unique to large lakes. And so at least two-thirds of the largest lost a significant amount of water.
Only those far from unpopulated areas recover
Although most of the lakes are dying of thirst, 24% increased the volume of stored water. However, there is one common factor in these cases that allows them to improve their situation and that is that they all tend to be located in unpopulated areas.
In fact, this trend is seen in areas with new reservoirs such as the Yangtze (China), Mekong (Southeast Asia) river basins, as well as in the interior of the Tibetan plateau or in the great plains of northern North America. and the Nile (North Africa). In Spain, the only reservoir with a positive trend is Alarcón in the province of Cuenca.
The reason for the impoverishment of the lakes seems not to be discussed. Behind him, according to Yao, climate change and increased human water consumptionAdded to this is the water seepage in at least a hundred large lakes.
2 billion people affected
Unlike rivers, lakes have never been so well viewed, although it is the latter that provides more water to the human population. For researchers, this detailed information should provide an incentive for water management. “If human consumption is one of the determinants of reductions in water storage, policies can be adapted to reduce it,” insists engineer Ben Livneh, co-author and CIRES member of the study.
And this is not a trivial problem. A quarter of the world’s population, or 2,000 million people, live near a drying up lake.This increases the water emergency.
In the eyes of scientists, there is an urgent need to incorporate both human consumption and climate change into the sustainable management of water resources. Only then will we be able to face the climate challenge presented.
Reference work: https://www.science.org/doi/10.1126/science.abo2812
Map showing the status of each lake and reservoir on the planet: https://cires.colorado.edu/globallakes
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