Beach profile and island cross-section manipulations in response to an offshore oil spill

摘要

Dauphin Island, Alabama, responded to the BP oil spill emergency by artificially manipulating its beach profile. A pile of sand was constructed at, and just behind, the seaward crest of the natural beach berm (Note: the term "beach berm" here refers to the traditional coastal geology definition of the nearly horizontal part of the beach or backshore formed through the deposition of sand by wave action). This manipulation, the sand pile, successfully contained oil in a narrow zone along the beachface and oil was not spread across the beach width at any time. The sand pile was roughly 2 m tall with a base width of roughly 7 m and contained a volume per unit length along the shore of about 7 m3/m (3 ydVft). This technique might have been valuable elsewhere and might be valuable in future spill responses to reduce the width of oil deposits on the beach. Dauphin Island also manipulated a low portion of the barrier island with the construction of a small dune-like feature away from the water. The emergency dune was designed using the guidance of Hallermeier and Rhodes (1988) to reduce the likelihood of barrier island overwash with oily water.