Briggs, Tiffany Roberts

Each year storms impact coastal areas, sometimes causing significant
morphologic change. Cold fronts are associated with increased wave energy and
frequently occur during the winter months along many coasts, such as the Atlantic and
Gulf of Mexico. The higher wave energy can be responsible for a large quantity of the
sediment transport resulting in rapid morphologic change. Using streamer traps, the
vertical distribution of onshore-directed sediment transport during two different cold
fronts on two low-wave energy beaches (i.e., along the northern Yucatan and southeast
Florida) were compared with the resulting morphologic change. The objectives of this
study are to: 1) analyze the grain size distribution (statistics) of sediment transported
during a cold front, 2) compare the vertical sediment distribution throughout the water
column, and 3) compare characteristics of bed sediment to the sediment within the water
column. Understanding the changing grain size distribution of bottom sediments in
comparison to directional transport (throughout the water column) should help determine the sediment fraction(s) being eroded or deposited, which could greatly improve
predictions of storm-induced morphology change.

Shorelines are a primary source of attraction for the nearly two million tourists who visit Palm Beach County annually. Many of Palm Beach County beaches are located on barrier islands, separated by a series of inlets which serve as access points to the Intracoastal Waterway. However, inlets are often cited as a source of erosion, through interruption of littoral drift and interaction with nearshore hydrodynamics (e.g., causing wave diffraction or refraction). In an effort to mitigate potential negative impacts of the economically important tidal inlets, Palm Beach County has installed a sand transfer plant (STP) at two inlet locations, the Lake Worth Inlet and the South Lake Worth Inlet. Through analysis of annual aerial photography and beach profile surveys taken between 2000 and 2009, this study will determine what effect, if any, these sand transfer plants are having on the inlet-adjacent shorelines north and south of the two inlets with STP, as well as an inlet without an STP (Boca Inlet). This study hopes to increase the understanding of shoreline dynamics in Palm Beach County, which could recognize important alongshore patterns, such as the occurrence of erosional hot spots, to assist in future mitigation efforts.