Wetland Change Analysis

Principal Investigator:

Stephen D. Prince

Wetlands are important incubators for fish and invertebrates, and play a vital role as habitat for migratory waterfowl. They are, for example, home to approximately one-third of the United State's threatened or endangered plants and animals, and provide irreplaceable migrating and nesting habitats for over half of migratory bird species. Wetlands are one of the world's most biologically productive ecosystems and provide a vast economic resource. In the southeastern United States, 96% of the commercial seafood catch and over half of recreational harvests depend on coastal wetlands. Wetlands are also important for filtering water flows within watersheds, which has implications not only for reducing nutrient and sediment losses but also for flood protection, storm water control, maintaining and protecting water supplies, and soil conservation. Wetlands are also important enclaves of biodiversity in an increasingly urbanized landscape. Despite these important ecosystem functions and economic benefits, over half of the wetlands of the conterminous United States have been lost.

Wetlands in the 60,000 square mile Chesapeake Bay Watershed (CBW) have been highly modified as a result of human activities and relative sea level changes. Accurate maps of wetlands are urgently needed for research, management and enforcement of regulations.

The Regional Earth Science Applications Center, University of Maryland (RESAC) is analyzing their extensive Landsat image data holdings, together with other data for the mid-Atlantic region, with the aim of mapping the status and trends of wetlands in the entire CBW. The analyses are being undertaken by the RESAC in collaboration with the Earth Satellite Corporation and partners in George Mason University, VA.

The project has developed a change-detection technique, named Outlier Detection Analysis (ODA), for use with satellite data in conjunction with existing maps. The US Fish and Wildlife Service National Wetlands Inventory wetland map is being updated using ODA with satellite data to maximizing the value of the original mapping and the discrimination capabilities of satellite data. In addition to status, the trends in wetlands since the NWI was completed (from 10-20 years ago) will be mapped.

In order to make these data accessible we are developing a decision support system with geospatial analysis capabilities.