Significant Land Cover Changes in US Coastal Regions

A new NOAA US-wide analysis shows that between 1996 and 2011, 64,975 square miles in coastal regions — an area larger than the state of Wisconsin — experienced changes in land cover, including a decline in wetlands and forest cover with development a major contributing factor.

Overall, 8.2 percent of the nation’s ocean and Great Lakes coastal regions experienced these changes. In analysis of the five year period between 2001-2006, coastal areas accounted for 43 percent of all land cover change in the continental U.S. This report identifies a wide variety of land cover changes that can intensify climate change risks, such as loss of coastal barriers to sea level rise and storm surge, and includes environmental data that can help coastal managers improve community resilience.

“Land cover maps document what’s happening on the ground. By showing how that land cover has changed over time, scientists can determine how these changes impact our plant’s environmental health,” said Nate Herold, a NOAA physical scientist who directs the mapping effort at NOAA’s Coastal Services Center in Charleston, South Carolina.

Among the significant changes were the loss of 1,536 square miles of wetlands, and a decline in total forest cover by 6.1 percent.

The findings mirror similar changes in coastal wetland land cover loss reported in the November 2013 report, Status and Trends of Wetlands in the Coastal Watersheds of the Conterminous United States 2004 to 2009, an interagency supported analysis published by the U.S. Fish and Wildlife Service and NOAA.

Wetland loss due to development equals 642 square miles, a disappearance rate averaging 61 football fields lost daily. Forest changes overall totaled 27,515 square miles, equaling West Virginia, Rhode Island and Delaware combined. This total impact, however, was partially offset by reforestation growth. Still, the net forest cover loss was 16,483 square miles.

“The ability to mitigate the growing evidence of climate change along our coasts with rising sea levels already impacting coastlines in ways not imaged just a few years ago makes the data available through the Land Cover Atlas program critically important to coastal resilience planning,” said Margaret Davidson, National Ocean Service senior advisor for coastal inundation and resilience science services.

C-CAP data identify a wide variety of land cover changes that can intensify climate change risks — for example, forest or wetland losses that threaten to worsen flooding and water quality issues or weaken the area’s fishing and forestry industries. The atlas’s visuals help make NOAA environmental data available to end users, enabling them to help the public better understand the importance of improving resilience.

“Seeing changes over five, 10, or even 15 years allows Land Cover Atlas users to focus on local hazard vulnerabilities and improve their resilience plans,” said Jeffrey L. Payne, Ph.D., acting director for NOAA’s Coastal Services Center. “For instance, the atlas has helped its users assess sea level rise hazards in Florida’s Miami-Dade County, high-risk areas for stormwater runoff in southern California, and the best habitat restoration sites in two watersheds of the Great Lakes.”

[mappress]
Press Release, August 25, 2014; Image: NOAA