Major Update to Satellite-Based Datasets Used to Assess Salt Marsh Vulnerability Nationwide

UVVR evaluates the ratio of unvegetated area to vegetated area across an entire marsh system, covering marsh plains, channels, ponds, and intertidal flats. Larger values of UVVR indicate more open water and less vegetation, which leads to more vulnerability to ongoing marsh loss.

Before using satellite imagery, all UVVR assessments were conducted using site-specific studies. However, individual studies are labor-intensive and require multiple aerial surveys, detailed merging of elevation and imagery data, and the interpretation of multiple imagery classes. Developing a method to use Landsat 8 satellite imagery enables users to get broad assessments of vulnerable salt marshes without requiring cumbersome site-specific studies. 

The USGS research team behind UVVR built numerous partnerships and collaborative working groups with users, such as the U.S. Fish and Wildlife Service, National Estuarine Research Reserves, and the National Park Service, to integrate UVVR into geospatial products that directly address specific marsh management questions. This recent UVVR update ensures the continued relevance and reliability of these geospatial products in conservation and land management decision making.