Saltwater intrusion threatens coastal groundwater, which serves as a vital drinking water source for numerous regions worldwide. This concern was highlighted in a study published in the journal “Nature Water” by researchers from the Johannes Gutenberg University of Mainz’s Institute of Geography (JGU) and the Climate Service Center Germany (GERICS) in Hamburg.
The findings indicate that more than 20 percent of the surveyed coastal areas have shown significant changes between 1990 and 2024. These changes include groundwater levels dropping by over 50 centimeters in some places. Such declines point to over-extraction, which potentially allows seawater to infiltrate and cause salinization.
Based on data collected from approximately 480,000 wells, the study warns that areas prone to drought, where populations heavily rely on groundwater, as well as regions where groundwater levels are close to sea level, are particularly vulnerable. Significant drops have been documented along the coasts of the USA, Central America, the Mediterranean region, South Africa, India, and southern Australia.
According to the researchers, global coastal areas could face fresh water shortages over the next 50 years. This anticipated crisis would impact not only the supply for over 30 percent of the world’s population but would also affect local food production and delicate ecosystems.
