PROTOTYPE APPLICATION OF NASA MISSIONS TO IDENTIFY PATTERNS OF WETLAND VEGETATION DEVELOPMENT WITHIN THE SOUTH SAN FRANCISCO BAY SALT PONDS

摘要

The South Bay Salt Pond Restoration Project is the largest tidal wetland restoration on the west coast of the United States. Monitoring vegetation development in these emergent habitats with remote sensing can provide restoration managers with an indication of ecological health and progress of development. Remotely sensed imagery was used to monitor vegetation development and to map vegetation patterns and biota changes historically, during, and after salt pond construction for ponds numbered A19, A20, and A2I. Percent vegetative cover was mapped using the Normalized Difference Vegetation Index (NDVI) from MODIS, Tasseled Cap Greenness (TCG) and NDVI from Landsat TM, and the Ratio Vegetation Index (RVI) from ASTER. Field parameters included in-situ measurements and geographic locations for percent vegetative cover, and site specific species information. Field data were incorporated into G1S, and vegetation was analyzed using spatial statistics methods and a qualitative post-classification comparison technique. NDVI values obtained from the Landsat scenes indicated a net gain of 3.35 acres of vegetation cover from February 2006 (before pond breaching) to August 2009 for pond A21 and 1.33 acres and 3.14 acres for ponds A20 and A19, respectively. Increases in vegetation indicate the marsh has built up to a steady-state condition to provide appropriate habitat for endangered plant and animal species and also indicates the success of restoration practices.