HR: 0800h
AN: H41C-0323    [Abstracts]
TI: Identification and Spatial Distribution of Remotely Sensed Sand on Fringing Reefs of Oahu, Hawaii
AU: * Conger, C L
EM: conger@hawaii.edu
AF: Department of Geology and Geophysics, S.O.E.S.T. University of Hawaii 1680 East-West Road, Honolulu, Hi 96822 United States
AU: Fletcher, C H
EM: fletcher@soest.hawaii.edu
AF: Department of Geology and Geophysics, S.O.E.S.T. University of Hawaii 1680 East-West Road, Honolulu, Hi 96822 United States
AU: Hochberg, E J
EM: hochberg@hawaii.edu
AF: Hawaii Institute of Marine Biology, S.O.E.S.T. University of Hawaii P.O. Box 1346, Kaneohe, Hi 96744 United States
AB: What surficial spatial patterns predominate among sand accumulations on fringing reefs? Do these patterns provide clues to transport mechanisms and factors governing deposition? Understanding of these spatial characteristics is integral for studying sand as a resource, a benthic habitat, and a mobile geologic unit on the sea floor. Using Quickbird imagery of fringing reefs on Oahu, Hawaii, we tested multiple data processing techniques with a linear classifier that utilized a fixed set of training groups and a truth image. Results show the Lyzenga method provided the best quantitative results, and analyst review finds this method to be the best qualitative spatial display as well. Highly accurate spatial data produced from the classified image, combined with bathymetry data from Shoals LIDAR were then utilized to begin identifying spatial distribution of the sandy substrate across the sea floor. Using basic geomorphologic reef descriptions and general spatial characteristics of the sandy substrate is the first step in identifying patterns of distribution within and juxtaposition to the reef. These results, when compiled from several sites, may begin to provide better understanding of sand's role in the reef geomorphology, though current results are not yet sufficient for predicting sandy substrate characteristics from remotely sensed data.
DE: 4546 Nearshore processes
DE: 1815 Erosion and sedimentation
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting