Scripps scientists trying to save San Diego's sand-starved beaches
Research by Scripps Institution of Oceanography
Last Updated: 161 days ago
SAN DIEGO - A group of researchers trying to find ways to protect San Diego beaches says a major reason for beach erosion is people.
Waves are a surfer's friend, but they can also be a beach's enemy.
At Cardiff State Beach, in a cramped metal storage container being used as an office, scientists from the Scripps Institution of Oceanography are scrutinizing the 89,000 cubic yards of sand deposited at the beach as part of SANDAG's regional sand project.
"We're trying to understand what happens to sand that we put into the system," explained oceanography professor Bob Guza.
Guza and his team are using a laser scanner on loan from the Army Corps of Engineers, mounting it about 30 feet up to monitor erosion. The group is also using high-tech sensors placed underwater at different depths to measure currents. It is an intensive effort to save San Diego's sand-starved beaches.
"That's why we have to pump sand from offshore, and it's only going to get worse," said Guza.
While waves can deplete sand, the bigger culprit may be flood control.
"When rivers flood, that small percentage of the time they flood, they bring out huge amounts of sand to beaches," said Guza.
Guza said dams have cut off about half the natural sediment flow in Southern California. What's more, in the North County, 40 percent of the coast has seawalls to prevent erosion, which also prevents sand from getting to beaches.
"Cut off the sand supply from the cliffs, reduce the sand supply from the rivers by half, there's a consequence," Guza said.
Guza is not suggesting the elimination of seawalls or dams, but feels people should learn how fast and where sand goes.
Sandy beaches attract tourists to the tune of $14 billion a year in California.
"This could be used in the future to help better design where you put sand," said Guza.
The project began Nov. 1 and will last through Feb. 15.
Guza said sea levels off the San Diego coast are also expected to rise in the future, which will threaten local beaches even more.
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