A TWO-PHASE COASTAL EVALUATION PLAN FOR HAZARD RISK ASSESSMENTS: AN EXAMPLE FROM CUMBERLAND ISLAND, GEORGIA

A two-part approach to evaluating coastal hazards was developed to aid coastal planning and management decisions for barrier island shorelines. After initial assessments, the technique can be followed for continued monitoring of coastal change. Examples from Cumberland Island National Seashore are given though the technique is applicable to any sandy shoreline.

The first component of the plan is a field-based program of observations and documentation. This involves (1) a simple geoindicators checklist of several hazards-related parameters including descriptions of the general setting, shoreline state, nearshore setting, and onshore setting; (2) beach profiling using a simple stake and horizon method; (3) a set of photographs to document the setting; and (4) recording site locations using a hand-held GPS unit. These should be repeated as often as possible, and at least yearly.

The second component of the plan is a computer-assisted analysis utilizing remote sensing and GIS technology. This involves (1) land use/land cover from satellite imagery; (2) shoreline change analysis from air photos and NOAA T-sheets; (3) evaluation of historical beach profiles (if and when available); (4) creating and managing a database; and (5) creating and maintaining a web site for maximum distribution of findings.

Field inspections of several sites on Cumberland Island National Seashore show that, at least for the sites visited, there are no major coastal hazards present on this undeveloped island. Shoreline change analysis from air photos confirmed this observation. A flow chart provides an easy to follow guide to initiating and continuing the proposed coastal evaluation technique.