|After - no berm|
“The volume of change did not approach the magnitude of what happened during Hurricane Bob,” said Jon Boothroyd, URI emeritus professor of geosciences, who has monitored erosion on Rhode Island beaches since 1977. “Some of the displaced sand went over the top dunes and was deposited in the beach driveways and parking lots. Some sand went offshore, but some of that will come back.”
He said that municipal workers in the area are already collecting sand from some of the beach parking lots and preparing to return it to the beaches.
|Charlestown Town Beach—or what's left of it—|
at high tide, morning of September 2.
They found that the berm – the area where most beachgoers place their blankets – lost about four feet in vertical thickness of sand, causing the beach to slope downward more steeply.
|The water comes up much farther onto |
the beach than it did before the storm.
According to Boothroyd, five factors dictate the amount of erosion that takes place: the size and intensity of the storm, the speed of the storm through the area, the tidal phase, the path of the storm in relation to the beach, and the time between storms.
Irene was relatively fast moving and hit as the tide was dropping, but it also spread out over a large geographic area with a path that put Rhode Island where the strongest winds occur. Wind speeds only reached about 50 miles per hour, and the storm surge was just three feet, which was a foot lower than during Hurricane Bob.
Boothroyd said that the net movement of sand from Rhode Island beaches is from west to east along the shore. That means that much of the sand that is displaced from beaches in South Kingstown, Charlestown and Westerly ends up in Galilee Harbor, where it is dredged out periodically. About 4,000 cubic yards of sand is deposited in Galilee each year on average, with an additional 5,000 cubic yards ending up in the breachways in Charlestown, Weekapaug and Quonochontaug.
Text republished with permission from South Kingstown Patch.com. Photos by Mauro Cavezzale.