Explanation of Indicator
The flooding created by hurricanes is a threat to the life and property of coastal residents. The most critical threat is to those residents within the category 1 hurricane evacuation/surge model zone developed by the National Hurricane Center. This zone shows all areas that would be inundated with water from a landfalling category 1 hurricane, defined as having sustained winds of 74 to 95 miles per hour. The category 1 hurricane evacuation/surge model zone includes all of Florida’s barrier islands, even those with areas of elevation above the category 1 level.
A 1993 study by the Florida Coastal Management Program (FCMP) indicates that nearly two million people reside within the category 1 zone. Populations within the category 1 hurricane evacuation/surge zone face a greater risk than those outside of this zone. The number of people within this zone is already significant, and continued growth increases the population at risk of damage from future storm events.
A 1993 report titled "Florida’s Coastal Future" was prepared for the Florida Coastal Management Program, Florida Department of Community Affairs, by the Southwest Florida Regional Planning Council. For a copy of “Florida’s Coastal Future” contact the Florida Coastal Management Program, Florida Department of Community Affairs, 2740 Centerview Drive, Tallahassee, FL 32399-2100, or at (904) 922-5438.
Hard copies of the reports are available at photocopying expense.
The report reflects data from several sources. A series of county population estimates was produced by the University of Florida’s Bureau of Economic and Business Research’s Division of Population Studies. Information on population at risk is from the eleven regional planning councils’ Hurricane Evacuation Study: Technical Data Reports, updated where necessary with locally derived information that is commonly found in the comprehensive plans of local governments. The Technical Data Reports are updated on an irregular basis; some reports have not been updated since 1985. All Florida counties are covered in the FCMP report.
The data have not been collected with the same frequency or over consistent time periods across all counties; this limits trend analysis as well as inter-county comparisons. In addition the methodology and assumptions, although generally consistent, do contain variations depending on when the study was conducted and by whom the study was conducted. For instance, two different models were used in the various studies to determine storm surge inundation areas.
The FCMP should create a statewide GIS system that overlays the most current model output of storm surge inundation on a map showing the spatial distribution of the population. The technology and data are available, however the start-up costs may be high.
Many counties with GIS capability are preparing this type of information and it may be possible to collect the information from those counties and assist other counties in preparing their own GIS system. This information could then be combined by the FCMP for use in a single report.
Because local governments are required to update their comprehensive plans every five years, which necessitates the calculation of updated population at risk of inundation estimates, the regional planning councils (RPCs) should establish a regular procedure for updating the Technical Data Reports. Currently, there is no regular schedule for updating the Technical Data Reports; instead the RPCs or the Army Corps of Engineers has been updating the reports as funding becomes available and as time permits. The FCMP and the RPCs should work together to establish a regular funding mechanism for these studies.