Analysis of Barrier Island Dynamics for Ship Channel Planning at Ship Island, Mississippi

Ship Island is located among a chain of barrier islands approximately 18 km south of Biloxi, Mississippi. During initial construction of Gulfport Harbor Ship Channel, 1901-1905, the channel alignment passed several hundred meters west of Ship Island. By the 1950's, westward island migration caused channel shoaling which eventually exceeded maintenance dredging, requiring realignment of the channel to the west around the advancing island tip. As the Ship Island barrier system migrates westward, the Gulf shoreline along the east end erodes, supplying sand to the advancing western tip. Five alternative ship channel alignments were studied as potential solutions to the shoaling problems caused by the island migration. A westward realignment was selected in consideration of the following criteria: construction and maintenance costs as a function of dredging requirements; channel navigability; siltation potential; and complexity of design and construction.