|News Update|| |
USGS releases nationwide marsh vulnerability maps
U.S. Geological Survey scientists have developed and made available a new mapping resource that can identify the most vulnerable marshes across the contiguous U.S. through a combination of remote-sensing and satellite technologies. These maps provide critical information to land managers and help inform marsh conservation and restoration strategies without costly site-specific or labor-intensive assessments.
The USGS has shown that marsh resilience can be evaluated by calculating the ratio of unvegetated area to vegetated area across an entire marsh system, covering marsh plains, channels, ponds and intertidal flats. The method, termed the UnVegetated-Vegetated marsh Ratio or UVVR. UVVR, uses data collected from 2014-2018 through remote sensing techniques, such as satellite imagery and aerial photography, to gauge how much of an individual marsh is open water and how much marsh plants cover it. By comparing the ratio of ponds, channels and tidal flats to marsh vegetation, land managers can determine which marshes stand the best chance of persisting in the face of changing conditions.
Salt marshes are among the most productive and valuable ecosystems in the world. The vegetation in these coastal systems acts as a natural buffer between land and sea, protecting coastline infrastructures under various conditions. Salt marshes also provide essential food, refuge and nursery habitat for commercially and recreationally important species, among other benefits. To continue providing these numerous services, salt marshes need to persist and expand to counteract the effects of sea-level rise and storms that physically erode them.
In the future, the USGS plans to regularly update UVVR assessments using aerial imagery, Landsat and newer satellites to support marsh restoration efforts by the U.S. National Park Service, U.S. Fish and Wildlife Service and coastal state agencies.