May 14, 2014 -- From 1996 to 2011, six percent of the U.S. West Coast region experienced land cover or land use changes—that’s a total of 9,700 square miles and the equivalent of four and one-half million football fields. With the release of land cover and change data gathered from 2010 to 2011, this discovery and many others are available instantly from the National Oceanic and Atmospheric Administration (NOAA) Coastal Change Analysis Program ( C-CAP).

The area covered by C-CAP data includes the intertidal areas, wetlands, and adjacent uplands of coastal California, Oregon, and Washington that drain west into the Pacific Ocean. C-CAP updates its nationally standardized database of regional land cover and change information every five years.

“The release of this latest data set gives C-CAP data users a 15-year picture of West Coast wetland losses and gains, development trends, and changes in forest areas, among other things,” says Nate Herold, C-CAP coordinator at the NOAA Coastal Services Center. “It helps them stay well-informed when making decisions dealing with hazard resilience, preservation of wildlife habitat, wetlands restoration, and other issues.”

Here are several findings on land cover changes in the West Coast region from 1996 to 2011:

• This coastal region added over 625 square miles of development, an area larger than the California cities of San Francisco and San Diego combined.
• About 70 percent of new development radiated outward from metropolitan areas in the form of dense residential neighborhoods with many impervious surfaces.
• This coastal region experienced a net loss of 3,200 square miles of forest (4,900 square miles of forests were cut while 1,700 square miles of forest were regrown). Such losses lead to forest fragmentation that affects the quantity and quality of wildlife habitat.
• There was little net change in wetland areas, and the changes observed were due primarily to sediment movement along the coastline, changes in lake level due to drought conditions, and the changing course of rivers in the floodplains.

C-CAP data and maps have been used by nonprofits, private industry, and government at all scales to make critical plans and decisions. For example, C-CAP data helped southern California communities assess areas at higher risk of wildfires or stormwater runoff. And the data helped a wetlands-conservation nonprofit to discover timber-harvesting activities in Oregon’s Yaquina watershed.

C-CAP also produces high-resolution land cover for select geographies. Currently, these more detailed data are available for a few locations in California and a large area along the lower Columbia River.      

C-CAP is part of the Digital Coast initiative, which is led by the NOAA Coastal Services Center. The Center works to protect coastal resources and keep communities safe from coastal hazards by providing data, tools, training, and technical assistance. Check out other Center products and services on Facebook or Twitter.