Mapping Hydrological Connections in the Great Lakes to identify Coastal Wetlands and Monitor Change with High Resolution Commercial Smallsat Data

Coastal wetlands are dynamic ecosystems constantly responding to fluctuating water levels, anthropogenic pressures, invasive species, and climate change. They are highly valued for their water treatment services, for providing critical wildlife habitat, removing nutrients that contribute to harmful algal blooms, and protecting neighboring shorelines from flooding and erosion due to storm surges and high lake levels. Within the Great Lakes Basin, coastal wetlands are defined as wetlands that receive waters directly from the Great Lakes or their connecting waterways. To support the informed management of coastal resources we have developed an automated algorithm to identify wetlands that are hydrologically connected to the Laurentian Great Lakes. Using both high resolution Smallsat commercial data and hydro-enforcement algorithms, we have mapped wetland connectivity at low, average, and high water levels within the Basin. Historical field observations and image interpretation are used to validate model results. For Lake Superior we correctly identified historical wetland connectivity for 94% of the sites. We are incorporating our connectivity wetland maps and inundation period into wetland change studies in order to better understand the impacts of climate, anthropogenic expansion and changing water levels on wetland ecosystems.