SALISBURY, Md. (AP) — As rising sea levels eat away at Chesapeake Bay islands and shorelines, geologists are using a new tool to show how rising waters could change Maryland’s shoreline.
Called lidar, the mapping technique shoots laser beams from airplanes to gauge the height of land.
The light detection and ranging system is being used by the state’s Department of Natural Resources and the U.S. Geological Survey (USGS) to study the potential effects of a rising sea.
Geologists hope the maps and projections will help local officials draw safer evacuation routes and make wiser development decisions.
“Because sea-level rise is a long-term thing, they don’t jump on it as a public concern,” said Curtis Larson, a retired coastal geologist who studies sea levels for the USGS. “It’s hard to get anyone to listen, not just elected officials, but the population in general. It’s a tough sell.”
Lidar models of the 26,000-acre Blackwater National Wildlife Refuge revealed the scope of the problem. The refuge, a preserve in Dorchester County, has lost nearly 8,000 acres to erosion and sea-level rise.
Specialists say it could be submerged by 2050.
“We know sea-level rise has been a major player in the significant amount of marshland loss here in Blackwater,” Bill Giese, a longtime Blackwater wildlife officer, told the Salisbury Daily Times.
“I guess the general thought is it’s nature and that’s a process that’s going to occur and you deal with it. But I think those maps were kind of an eye-opener,” he said.
In Worcester County, planners say lidar maps aren’t as dramatic but do show significant inundation of marshes and wetlands.
Even under stable sea levels, County Commissioner Virgil Shockley said, a severe hurricane would drown a Wal-Mart parking lot on Route 50 miles from the beach.
Scientists project that sea levels will rise 1 to 3 feet by 2100.
Sea-level rise will exacerbate coastal flooding, shoreline erosion and result in a “slow but steady” submergence of tidal wetlands, the project scope says.
On Hooper Island in Dorchester, a moderate estimated sea-level rise would wash away the island’s causeway that connects residents to the mainland.
The worst-case scenario could wash away the island. The causeway is frequently flooded and sometimes navigable only by residents who know its twists and turns by heart.
“People drive through it as long as you know where it curves because you can’t see it,” said Richard White, a retired professor who lives about a foot and a half above sea level on the island.
The rising sea, which has swallowed hundreds of low-lying islands in the Chesapeake, could threaten populated areas next.
In Public Landing, inn owner George Hogeboom told the newspaper that he has watched the small islands dotting the Chincoteague Bay slowly submerge in the past decade.
The parking lot to the public pier has flooded above 3-foot posts on the boat ramp.
“It’s nothing startling,” he said, “but it just seems to be happening more and more often.”