Paper No. 82-5
Presentation Time: 9:00 AM-5:30 PM
A DECADE OF DUNES: EFFECTS OF HURRICANE IKE CIRCA 2008
Coastal nourishment programs on South Padre Island, Texas have been evaluated since the early 1990s, and they have led to millions of dollars in expenditures to cope for erosional problems. The impacts of large storms periodically affect local structures (Pethick, 2015). This study compared dune profiles on South Padre Island, Texas over a nine-year period. It demonstrates to the public the importance of dune restoration in protecting the shoreline. The comparison provides records of pre-Hurricane Ike data from 2008, post-Hurricane Ike data from 2008, and transects completed in the fall of 2015. Transects were taken from six locations (2 un-vegetated berms, 2 with established vegetation on the dunes and 2 with re-vegetated dunes), with each location providing detailed profiles showing the dynamic morphological changes of sand dunes in a nine-year comparison. The dunes with established vegetation and re-vegetation have grown over the study period. The un-vegetated berms have been re-vegetated during the study period. The Texas General Land Office reports that 64% of the Texas coast is eroding at an average rate of approximately two meters per year (2015). Additionally, some locations across the 590 kilometer shoreline are losing more than nine meters per year. Property values decrease, beach faces become less aesthetically pleasing, and tourism declines creating economic hardship. Coastal dunes become developed with suitably strong onshore winds, sufficient sediment supply of medium to coarse sorted sand, and plentiful dune vegetation to assist in the stabilization of particles (Woodroffe, 2002). South Padre Island has had an active dune revegitation program for the past 12 years. This program has led to the re-establishment of a continuous duneline within the city limits.