Global water crisis: The world’s rivers are drying up at the most worrying rate in 30 years, according to the World Meteorological Organization (WMO). Its latest report on water resources also warns of the low level of aquifers in several places, including southern Europe, and specifically singles out Spain for “cases of overexploitation” of groundwater.
The WMO study shows that in 2023, 45% of the world’s river basin territory was drier or much drier than its historical average. If you look at the last 33 years, you can see how the percentage of basins and lands whose rivers carry less water than normal is increasing. In 1991, it was 19% and the line increases (with its ups and downs) until it reaches 45%. “They experienced the driest conditions in 33 years,” the report explains. The previous driest years were 2021 and 2015.
The situation reveals “strong pressure on water resources”, summarizes the WMO, “with five consecutive years during which rivers have flow rates below average as well as liquid inflows into reservoirs”. In his conclusions, he emphasizes that this shortage “affects populations, agriculture and ecosystems”. And this adds “the most pronounced mass loss of glaciers in 50 years”.
To this must be added the chaos water that the climate crisis contributes to: 2023 was the hottest year measured on the planet (high temperatures evaporate more water and force plants to consume more liquid); There have been droughts and heatwaves across the world and episodes of torrential rain have been recorded, causing deadly floods in Europe and Spain.
Guadalquivir and Guadiana, among the dry areas
The rivers that suffer the most from water scarcity are in America. From the north to the south of the continent almost without exception – only Alaska is spared, specifies the document – the courses have discharged less (or much less) liquid than expected into the sea. The basins of the Mississippi, the Colorado and the Ohio in North America and “nearly all” of the basins of Central and South America. The Amazon, for example, recorded its lowest level since 1902 near the Brazilian city of Manaus.
Among the rivers that carried more water than average, the report highlights the Danube and the Dnieper as well as the basins on the east coast of Africa. On the world map of orange zones, that is to say with less water, appear the Guadalquivir and Guadiana basins in Spain. Among the blues with more flow than usual, the Cantabrian and Galician basins.
Depleted aquifers
In addition to surface water, the report also looks at groundwater: aquifers – after all, 99% of the planet’s liquid resources are found underground. Levels were below or much below normal in North America, particularly in the western United States, as well as central and northern Chile, western and southwest Brazil, Australia , in central Europe and southern Europe. Here are named Spain, Portugal and a good part of France.
“It is not easy to identify the causes that mark the regional evolution of aquifers because they depend on both climatic and anthropogenic variables,” explain the technicians. If there is no precipitation, the water table level obviously drops because the underground reservoir is not replenished. But there are cases where the collapse of aquifers is not linked to precipitation but to “decades of overexploitation”, such as in Chile or Jordan, the report indicates.
But there are also circumstances in which droughts and excessive pumping for irrigation combine. “Climatic and human factors combine. » In this sense, we highlight the lack of rain in California, added to the high level of water withdrawals. And it is emphasized that Europe “has been affected by several droughts in recent years, but there is overexploitation of aquifers, particularly in the south of the continent.” Does WMO give examples? France, Hungary and Spain.
