LSU Professor Robert Twilley is conducting aerial research of Louisiana’s river delta system in partnership with NASA that will be used to help NASA begin monitoring delta growth worldwide.
“River deltas are the primary mechanism, at least in this part of the world, that coastal land is built with and sustained,” LSU professor Mathew Hiatt said. “Sediment is delivered to the coast via the river channels and the deposition basically forms the delta.”
River deltas are important for a host of reasons. Over the course of thousands of years, deltas have formed fertile farmland, oil and gas reserves, major fisheries, and the rivers where deltas take shape often become major areas of commerce. Some of the first cradles of civilization were formed around river deltas, and now some of the biggest cities in the world are located around them.
“Deltas are big economic engines,” Twilley said.
Understanding river deltas could help produce solutions to Louisiana’s wetland loss, since they are the primary engine by which coastlines replenish the land.
“The rivers have to continually add new sediment because as sea levels rise if the land doesn’t rise with the sea level, then all of a sudden that land becomes water again,” says Twilley.
Twilley has been conducting research around the Wax Lake River Delta system for around 16 years, looking at it as an analog for how river systems grow. Wax Lake is a large body of water in St. Mary Parish that was converted to an outlet channel to divert water away from the Atchafalaya River and into the Gulf of Mexico. After many years of conducting this research on the ground, Twilley was contacted by NASA.
“NASA said 'hey, we know about the research y'all are doing over by Wax Lake and we’ve got some new satellite sensors that we’re testing that we think can monitor the growth of deltas around the world. Would you be interested in helping us calibrate the sensors?' and I said yes," Twilley explained.
NASA is currently testing the sensors, flying them up to about 30,000 feet above river deltas to analyze them. Twilley and members of the field teams analyze the river deltas on the ground and then compare them to the information that the sensors pick up in order to test their accuracy.
“The sheer complexity of the project is amazing," the forecaster for the project, Professor Paul Miller, said. "Just the amount of moving pieces and the field teams that they have just collecting data all coordinated at the same time, it’s just incredible. Some of those planes can only fly when it’s completely clear sky conditions, any clouds are a problem. Some can handle clouds but no precipitation. If it’s too windy then the field teams can’t be on the surface when the airplanes fly over so all the stars have to align on the weather side of things in order for them to execute the field campaign as planned.”
The sensors that NASA is using to monitor river deltas are highly sophisticated and must be tested thoroughly before they are attached to a satellite, which is why they reached out to LSU.
The research that Twilley and NASA are conducting will lay the foundation for a deeper understanding of river deltas across the globe.
“It’s pretty cool to do all of this work on the ground for years looking at little plots, now all of a sudden with NASA to think that you can expand that to the whole globe,” said Twilley. “That gives you a real sense of impact because it’s not just Louisiana. What we’re learning here in Louisiana on our delta can be used to understand deltas around the world. That’s a researcher's dream.”