Hurricane Ivan's Impacts on the Alabama Coast

摘要

This paper summarizes the severe impacts Hurricane Ivan produced along the Alabama coast as the storm made landfall along the western limits of the City of Gulf Shores, AL, in the morning hours of Sept. 16, 2004. The Category 3 hurricane produced storm surge levels of 10-15 feet along the barrier beaches of Gulf Shores and Orange Beach. In both of these popular tourist communities, the combined effects of winds, surge, waves, and rain produced substantial storm damage to the sandy beaches and upland private homes, condominiums, hotels, coastal roads, and utilities. Two engineered beach nourishment projects experienced significant levels of erosion. Post-storm inspections of the beach and of buildings and roads indicate a relationship between nourished beaches and the level of property damage incurred. Property damage was more severe in the non-nourished areas, which have experienced long-term beach erosion and shoreline recession due to storm impacts and inlet-induced sand starvation. Conversely, storm damage to structures and roads was reduced behind the wider, artificially nourished beaches in the area. The severity of the storm, particularly the significant storm surge level, also revealed flaws in building foundations, construction techniques, and siting decisions of Gulf-front buildings. Many building failures represented predictable, avoidable problems that in most cases represented designs outside the norm for coastal construction and the local building codes. Building codes in Gulf Shores and Orange Beach had been updated following Hurricane Georges in 1998 and have been further updated following Ivan. Post-storm recovery efforts, funded in great part by the Federal Emergency Management Agency (FEMA), have included debris removal and the reconstruction of public infrastructure and utilities. Post-storm emergency sand berms have been built in numerous areas using screened storm overwash sand. Additionally, a large-scale beach nourishment project is under way in spring/summer 2005 to restore 15.5 miles of shoreline from Orange Beach to Gulf Shores, using 6 million cubic yards of sand from offshore shoals in the Gulf of Mexico.