Enhancing coastal function by sensible setback for open duned coasts
Solutions to Coastal Disasters '02: 794-807
As recently advocated by Healy and Dean (2000), assessment of appropriate development setback based upon identified coastal hazard along open duned coasts may be evaluated from 4 essentially independent factors, viz., historical shoreline change rate, decadal term "cut and fill", a sea level rise effect, and a dune stability factor. The setback delineated is based upon a 100 year planning horizon, and derived from the beach-dune profile. The initial setback determination is then subjected to 3 tests, viz., (i) is there sufficient sand in the beach dune reservoir? (ii) is the setback zone subject to storm surge flooding? and (iii) is the setback zone subject to tsunami inundation? The calculated setback zone may also function for other purposes including coastal landscape preservation, ecosystem protection, and preservation of cultural sites. Major difficulties arise when applying the scheme to already subdivided coastlines, when community views must be considered in an ICZM context. This methodology of determining one integrated hazard zone is considered superior to implementing sequential zones of supposed reducing hazard.