Developing Consistent Methods for Mapping Sea Level Rise in Southeast Florida
The peninsular shape and low elevation of Southeast Florida make it vulnerable to inundation, particularly inundation from sea level rise, and the region’s high population adds urgency to mapping and understanding this phenomenon. The region is already experiencing increased flooding during heavy rain and high tide events, saltwater intrusion into freshwater aquifers, and greater impacts during coastal storms. Inconsistent inundation-mapping methods have made it difficult to achieve a regional vulnerability analysis that is needed to help prepare Southeast Florida for these impacts.
To assist the Southeast Florida counties of Monroe, Miami-Dade, Broward, and Palm Beach in developing a unified set of methods and criteria for creating sea level inundation maps, a two-day technical workshop was held in April 2010. The NOAA Office for Coastal Management and the Center for Operational Oceanographic Products and Services facilitated discussions to help workshop participants understand state-of-the-practice inundation-mapping methods, define local challenges, and ultimately agree upon a consistent set of methods and criteria. These are the same methods used to create the Digital Coast Sea Level Rise and Coastal Flood Impacts Viewer. After consistent mapping methods were developed, the counties and the South Florida Water Management District worked together, via the Southeast Florida Regional Climate Change Compact, to develop a vulnerability assessment of the Southeast Florida region for one-, two-, and three-foot sea level rise scenarios.
The assessment revealed that all four counties are vulnerable to sea level rise and highlighted areas of particular concern where adaptation measures need to be in place. For example, in the one-foot scenario, 75% of hospitals, 65% of schools, and 71% of emergency shelters in Monroe County would be under water. In terms of dollar amounts, taxable property values vulnerable across the region in the one-foot scenario are greater than $4 billion, with values rising to over $31 billion in the three-foot scenario. With the regional vulnerability analysis complete, the counties are now able to coordinate policies and adaptation measures to prepare Southeast Florida for the projected impacts of sea level rise.