Boston scenarios

The Globe commissioned Applied Science Associates of Narragansett, R.I., to create aerial images simulating Boston's vulnerability to flooding in 100 years under several scenarios.

In each case, it was assumed that global warming would cause a sea level rise of 15 inches. That rise was chosen because it is midway between the 7 to 23 inches that scientists project oceans will rise by the end of this century. Boston is also projected to settle 6 inches by the end of the century, and the simulations took that into account.

The first simulation shows there would be little or no flooding on a nice day in Boston during high tide.

The second simulation shows Boston during high tide and a 2.5-foot storm surge that would be expected during a northeaster. Flooding would occur largely in parts of the Financial District and East Boston.

The third simulation showed what would happen during a category 2 hurricane, with a storm surge of at least 4.5 feet. South Boston, North Dorchester, the downtown waterfront, Roxbury, and the South End would be flooded, and Boston Harbor would would wash over the Charles River Dam to flood Cambridge and the Back Bay.

BETH DALEY