Boston Harbor Islands is home to the only partially drowned drumlin field in North America. The islands are dominated by one or several oval-shaped hills called drumlins that were formed during the last glaciation. As the sea level rose with the end of the glaciation, the Boston Harbor drumlin field was gradually flooded. Following a rapid decrease in sea level, the land rebounded upward. This left behind hills sticking out of the water, also known as drumlins. The gradual erosion of drumlins has provided sediment to form sandy spits often connecting nearby drumlins, creating the islands and bluffs we see today.
There is no shortage of historical and natural resources located at the Boston Harbor Islands. The area is an important breeding area for coastal breeding birds that supports a significant portion of Massachusetts breeding colonies of wading birds (egrets, night-herons, ibis), eider ducks, and gulls and cormorants. The Islands are also home to the northernmost breeding area for American Oystercatchers in the United States. The coastal and nearshore wetlands are important habitats providing wildlife habitat and aid in reducing flooding by storing floodwaters and slowing wave energy. Nearly all the Boston Harbor Islands contain significant cultural and infrastructure resources relating to early historic and indigenous use, resource extraction, trade and navigation, military use, and recreation facilities. Included in the park are six listings on the National Register of Historic Places. Three of these six listings are also National Historic Landmarks.
Although flooding and sediment erosion and deposition along coastal park shores are natural processes, the rate and extent to which these processes are occurring is increasing, mainly due to accelerating sea-level rise (SLR) and increased frequency of intense storms. Although there are 34 islands and peninsulas located at Boston Harbor, the study focuses on Peddocks, Thompson, Long, Georges, Gallops, Lovells, Little Brewster, Great Brewster, and Calf.
The goal of the project is to create a Spatial Decision Support System (SDSS) to help park managers/stakeholders make decisions about which high risk focus areas to choose in terms of collaborative climate adaptation efforts. The project will achieve this by creating two tailored Multi Criteria Evaluations (MCE) using raster data and weighted overlay analysis. The first round is determining “at-risk areas.” The categories of risk I’m looking at are storm risk, flood risk, and erosion risk. The storm risk category includes three different sea level rise timelines (2030, 2050, and 2070) with different CFEPs (10% and 1%). The flood risk category includes only elevation data. The erosion risk category includes data on shoreline type, distance from a bluff retreat zone, and land cover vegetation levels. The result of the first MCE are located in the Coastal Exposure tab. The map depicts “at-risk areas” for focal resources during the three separate sea level rise scenario years.
