Shoreline and Beach Volume Change Before and After the 2004 Hurricane Season, Palm Beach County, Florida

摘要

This paper quantifies the shoreline and volume change utilizing three LIDAR data sets that were collected in Palm Beach County before and after the 2004 hurricane season. The beaches in Palm Beach County were significantly affected by Hurricanes Frances and Jeanne. Shoreline positions were extracted from the LIDAR-derived digital elevation models (DEMs), and the DEMs were differenced to yield volume change. The 52.4-kilo-meter-long study area lost nearly 5.8 million cubic meters (m~3) of sediment due to the 2004 hurricane season, with major erosion occurring to the berm, sandbar, and the northerly sections of ebb tidal deltas. On average, nearly 10 meters of shore ero- sion was observed. Correlation between shoreline movement and volume change was quantified. A poor R~2 value of 0.39 was found between shoreline and volume change before the hurricane season in the northern section of Palm Beach County because of beach nourishment and inlet dynamics. However, a relatively high R~2 value of 0.78 in the southern section of Palm Beach County was found due to little disturbance from tidal inlets and coastal engineering projects. The 2004 hurricane season reduced the R~2 values to 0.02 and 0.42 for the north and south sections, respectively.