Assessing the Vulnerability of the Alabama Gulf Coast to Intense Hurricane Strikes and Forest Fires in the Light of Long-term Climatic Changes

Any realistic assessment of the impacts of future climatic changes on the Gulf coast region must take into consideration the effects of global warming on hurricane activity. It has been hypothesized that the hazard of wildfire increases significantly after an intense hurricane strike. However, the lack of longterm records on intense hurricane landfalls and major wildfires has prevented a vigorous evaluation of the hypothesis of hurricane-fire interactions. In this paper, we present a 1200-year record of intense hurricane strikes and wildfires on the Gulf coast based on a study of overwash sand layers, fossil pollen and dinoflagellates, and microscopic charcoal particles in a sediment core retrieved from Little Lake, Alabama. Our data suggest that intense hurricanes (category 3-5 according to the Saffir-Simpson scale) directly struck coastal Alabama at least seven times during the past 1250 years, implying an overall return period of about 180 years. Three of the four peaks in charcoal concentrations are associated with overwash sand layers, implying that major wildfires occurred shortly after intense hurricane strikes. Recent studies suggest that a climatic shift after 1995 may result in heightened hurricane activity along the Gulf coast in the next several decades. This could also lead to increased fire hazard for the forests of the Gulf coast states. Chapter 13