Wednesday, August 20, 2008

High-tech mapping forecasts worsening floods, wetland losses in mid-Atlantic US (US): Decades had passed since a storm sent saltwater and fish into corn and bean fields west of Prime Hook National Wildlife Refuge. Then, a late-season storm in May caused flooding along the Delaware Bay and pushed fish way beyond their normal, bay, river and creek habitats.

Some state environmental officials wonder if what happened in May could be a glimpse at Delaware's future. They are developing a sea-level adaptation plan for the state -- a project that will use high-tech mapping and modeling to predict what rising sea levels could mean for a state with 25 miles of ocean coast and even more land along the Delaware Bay and River, the Nanticoke River and dozens of tributaries in the bigger river systems.

"It's not just Sussex County we're worried about. It's everywhere," said David Carter, an environmental program manager with the state coastal management program. By some estimates, every 1-foot rise in sea level translates to a 1-foot rise in flood levels.

….The International Panel on Climate Change has estimated that sea level will rise from as little as 7.2 inches to as much as 23.6 inches by 2100. That uncertainty makes sea-level rise a challenge for coastal and environmental planners, Carter said. His group, working with other state and federal agencies, will use LiDAR digital photography to map vulnerable areas. LiDAR uses light detection ranging to use a radar-like pulse of light to map the land, allowing it to "see" the bottom of clear, shallow waters...Noted Carter, "It's much more accurate. It's got a huge amount of uses."

So while Carter and his staff will be using LiDAR mapping as a tool to model sea-level rise scenarios, the same maps can be used to revise federal flood insurance maps….

Part of (left to right) Virginia, Maryland, and Delaware -- the Delmarva Peninsula. By "Papa November"?, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 2.5 License

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