Speaker: Brian Fulfrost

Topic:  Mapping Marshes and Mudflats from Space: Methods, Challenges and Results from the South Bay Salt Pond Restoration Project

San Francisco Bay has lost an estimated 85 percent of its historic wetlands to fill or alteration. This dramatic decline in tidal marsh habitats has caused populations of marsh-dependent fish and wildlife to dwindle. There are a range of efforts to help restore the mosaic of tidal wetlands within San Francisco bay to their “original” extent. The South Bay Salt Pond Restoration Project is the largest of these efforts and is focused on restoring 15,000 acres of former salt ponds in the south bay. The Habitat Evolution Mapping Project (HEMP) is an effort to assist the salt pond restoration by mapping the distribution of tidal marshes and mudflats using semi-automated classification of high-resolution satellite imagery. We used supervised classification and extensive ground truthing to map dominant vegetation types representing salt, brackish and freshwater marshes. We also used band indices (e.g. NDWI, MSAVI2) and regression analysis to map the extent and distribution of mud flats in shallow water. The study area was first mapped yearly between 2009 and 2011 using Ikonos imagery. We are currently remapping the study using Worldview-2 imagery from 2019 (and 2021 is planned). The methods, challenges, and preliminary results exploring changes between 2009 and 2019 will be presented.