Abstract
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This paper demonstrates a practical step-wise method for modelling wave energy at the landscape scale
using GIS and remote sensing techniques at Alphonse Atoll, Seychelles. Inputs are a map of the benthic
surface (seabed) cover, a detailed bathymetric model derived from remotely sensed Compact Airborne
Spectrographic Imager (CASI) data and information on regional wave heights. Incident energy at the reef
crest around the atoll perimeter is calculated as a function of its deepwater value with wave parameters
(significant wave height and period) hindcast in the offshore zone using the WaveWatch III application
developed by the National Oceanographic and Atmospheric Administration. Energy modifications are
calculated at constant intervals as waves transform over the forereef platform along a series of reef
profile transects running into the atoll centre. Factors for shoaling, refraction and frictional attenuation
are calculated at each interval for given changes in bathymetry and benthic coverage type and a nominal
reduction in absolute energy is incorporated at the reef crest to account for wave breaking. Overall
energy estimates are derived for a period of 5 years and related to spatial patterning of reef flat surface
cover (sand and seagrass patches).