New Satellite Method Measures Beach Tides with Meter-Scale Accuracy

Researchers at the Technical University of Munich (TUM) and the University of Oxford have developed a new satellite-based method to measure variations in tidal water levels along coastlines. The technique uses the beach as a natural measuring tool by combining the visible shoreline position in satellite images with the known beach slope.

This new approach provides data at a resolution of approximately 100 meters, a significant improvement compared to previous satellite-based methods which typically offered a resolution of about 10 kilometers. Using this method, researchers were able to identify tidal differences of nearly one meter across a 90-kilometer stretch of coastline in New Zealand.

The method can enhance coastal protection, flood forecasting, and navigation, particularly in areas lacking local tide gauges, such as parts of Africa and Southeast Asia. It can also help assess compound flood risks arising from heavy rain, storm surges, and high tides.

The study utilized over 40 years of satellite imagery from NASA's Landsat program and the U.S. Geological Survey. The findings were published in the journal Communications Earth & Environment. Researchers anticipate that the method could be further refined with additional satellite data from programs like Copernicus Sentinel-2.