Predicting Changing Landscapes
Interactive teaching tools augment our comprehension of geomorphology, the study of the science of sand
Half the world’s beaches could disappear by 2100. Erosion and sea-level rise are swallowing shorelines in every corner of the globe. But how do we know which ones are most at risk?
That’s the central question driving teaching advancements by Alejandra Ortiz, assistant professor of geology.
“By understanding the underlying processes that drive landscape change,” said Ortiz, “we can start to predict how a landscape will change over time.”
The way that sand and water travel across coastal areas impacts their topography, the forms and features of the landscape. Geologists are interested in visualizing these physical landscape changes and making predictions on future topography given certain conditions, like rising sea levels or intense storms from climate change.
But just viewing a landscape in the present is limiting because of the long timescales and large spatial scales over which landscapes change. Ortiz has ideas about how to change that.
This summer, Zack Dubosky ’22 developed and constructed two tools selected by Ortiz to enhance the learning and research of geomorphology at Colby. Geomorphology is the study of how physical landscapes change over time. Essentially, said Dubosky, “it’s the science of sand.”
First, Duboksky constructed an augmented reality sandbox based on the model developed by researchers at the University of California, Davis. Its key elements are 200 pounds of white sand, a 3-D camera, and a projector. First, a user molds a landscape in the sand, then the camera mounted above the sandbox scans the shapes. The projector, connected to topographical software, then overlays a topographic map of the sand elevation onto its surface. This process allows for the ability to read topographic maps in 3-D.
Software connected to the sandbox can also simulate the effects of rain, illustrating the subsequent water dispersal. “This is all based on real physics,” Ortiz said. “Students might predict what would happen, and they can test that in real time.”
Ortiz anticipates incorporating the sandbox into lab courses and teaching students to write scripts in Python that model more sophisticated topographical changes and sediment displacement.
Dubosky’s second project involved coding and soldering a dozen low-cost ocean-wave pressure gauges for students to use in the field.
Based on designs by researchers from Mississippi State University, the geology major built gauges using a PVC pipe, a microcontroller, and a pressure sensor. On the inside of the pipe, two circuit boards record wave pressure. After deploying the gauge in the ocean for a few hours, users can obtain pressure readings created by waves passing over them, Dubosky explained.
These gauges will allow students to collect real-time geomorphological data—for a fraction of the cost—and analyze it using the principles of wave theory they learn during the semester.
Contributing to this investigation of the effects of climate change on beaches, Dubosky has put his gauges to the test at Colby’s Allen Island in the Gulf of Maine. He’s characterizing the island’s wave climate—the height, direction, and period of waves—and collecting data to help inform future predictions about the shoreline.
“Knowing the magnitude of waves can tell us what we can expect regarding our shoreline, like if a beach is going to be there in 10 years,” Dubosky said.
“We’re always trying to find different or better ways to explain things. These tools allow us to … reach more people more easily.”
Alejandra Ortiz, Assistant Professor of Geology
As researchers grapple with the global loss of sandy beaches, expanding hands-on opportunities to learn wave theory and understand which areas to prioritize is becoming even more crucial.
“We’re always trying to find different or better ways to explain things,” said Ortiz. “These tools allow us to … reach more people more easily.”
