There are concerning predictions about saltwater entering into coastal groundwater sources, according to a recent study conducted by scientists at NASA’s Jet Propulsion Laboratory (JPL). This phenomenon is predicted to affect around 77% of coastal streams globally by the year 2100. It can erode infrastructure, harm ecosystems and make freshwater supplies unfit for human use.
The balance between rainfall recharging freshwater and seawater pressure moving inland causes saltwater intrusion which is the passage of seawater into underground freshwater aquifers. But this balance is being upset by climate change. The force of saltwater intrusion is growing as a result of coastlines moving inland due to rising sea levels brought on by global warming.
At the same time, the problem is made worse by slower groundwater recharge brought on by less rainfall which weakens the flow of freshwater toward the ocean. In order to determine how reduced groundwater recharge and increasing sea levels may affect saltwater intrusion, the study examined more than 60,000 coastal streams worldwide. The results show that in 82% of the watersheds under study, saltwater might be forced inward by increasing sea levels alone and in 45% of these regions slower recharge could result in intrusion.
Notably, areas including sections of the Gulf of Mexico, Western Australia, and the Arabian Peninsula are especially at risk. JPL groundwater scientist Kyra Adams, the study’s primary author emphasized that effective management of saltwater intrusion requires an awareness of local circumstances.
“Depending on where you are and which factor dominates, your management implications might change,” she said.
NASA and the US Department of Defense jointly financed the project in an effort to assess the effects of climate change on coastal infrastructure. To estimate possible future scenarios for saltwater intrusion, researchers used data from the World Wildlife Fund’s HydroSHEDS database.
This study emphasizes the critical need for adaptive management measures to safeguard essential freshwater resources given the substantial hazards that climate change continues to pose to coastal regions.
