Los Angeles: Scientists have created high-resolution maps of points around the globe where groundwater meets the oceans — the first such analysis of its kind that may help protect both drinking water and the seas. In a study published in the journal Geophysical Research Letters, researchers from The Ohio State University in the US showed that nearly half of fresh submarine groundwater discharge flows into the ocean near the tropics.
They also found that regions near active fault lines — the area around the San Andreas Fault in California, for example — send greater volumes of groundwater into the ocean than regions that are tectonically stable. They found that dry, arid regions have very little groundwater discharge, opening the limited groundwater supplies in those parts of the world to saltwater intrusion.
The team worked with researchers at NASA’s Jet Propulsion Laboratory and the University of Saskatchewan to combine topographical data from satellites and climate models to show the flow of groundwater around the world’s coasts. The findings may help coastal communities better protect and manage their drinking water.
The research work, the first near-global and spatially distributed high-resolution map of fresh groundwater flow to the coast, could give scientists better clues about where to monitor groundwater discharge. When researchers think about coastal water quality and the way water affects the biochemical makeup of the world’s lakes and oceans, they typically think about rivers and streams — and for good reason. Most of the water that gets to lakes and oceans comes from surface water sources.