NASA Grant Supports UCI-led Project to Remotely Monitor Changes in Beaches, Dunes
New techniques to measure coastal topography will improve understanding of flood risk
July 5, 2022 – With a $675,000 grant from NASA, researchers at the University of California, Irvine and the University of Houston are launching a new project focused on remote monitoring of sandy beaches and dunes.
“Beaches represent our first line of defense against damaging coastal storms,” said co-principal investigator Brett Sanders, UCI professor of civil and environmental engineering. “Sea level rise combined with human-influenced sand starvation is contributing to beach loss, which in turn amplifies coastal flood risk.”
Sanders noted that data characterizing fluctuations in the amount of sand along the coast is challenging to acquire over large scales and with sufficient accuracy to understand the site-specific processes and factors driving beach loss.
“Sea level rise presently amounts to several millimeters per year, but beach topography can change by more than a meter in a single month,” he said. “We won’t have good estimates of future flood risks along wave-dominated coasts like those found in Southern California without better data monitoring changes in beach topography.”
Working with Pietro Milillo, UH assistant professor of civil and environmental engineering, Sanders will develop new observational strategies and techniques to measure sandy beaches and dunes. They will use technologies such as interferometric synthetic aperture radar and lidar, which involves targeting an object with laser light to obtain precise size and distance information.
In an early phase of the project, the team will combine data provided by the German Aerospace Center’s TanDEM-X and NASA’s ICESat-2 satellites with surface elevation models and lidar observations at four beach/dune sites in Southern California. The researchers will conduct measurements on a monthly and, in some cases, submonthly basis for three years.
“Our first goal is to document surface elevation changes in very high resolution and to verify if our satellite-based approach can match the accuracy we can achieve with proven ground-based and aerial sensors,” said Milillo, who was previously an associate project scientist in UCI’s Department of Earth System Science. “If this proves successful, we’ll be positioned to document surface elevation along all coasts every month, with better coverage and at lower costs to coastal communities than has ever been possible before.”
This work could lead to improved understanding of sand movement; the identification of hot spots of sand depletion; and early detection of beach thinning, which could help trigger adaptation efforts.
The NASA-funded project also will include modeling of coastal flood risks based on the observed transformations in beach topography along with data characterizing coastal waves, tides and sea level changes.
“We know future flood risks are increasing, but it’s been difficult to say exactly by how much and when due to uncertainty in coastal topography. This work will increase our confidence in flood risk estimates for the next several decades,” Sanders said.
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– Brian Bell / UCI