Specialty Group Sponsors:Coastal and Marine Geography
Geographic Information Science and Systems
Marine/Coastal GIS and
Acoustic Remote Sensing
AAG Annual Meeting, Denver
April 8, 2005
Photo by
D.J. Wright, E. Lundblad*, E. Larkin^, R. Rinehart, Dept. of Geosciences, Oregon State University
J. MurphyNOAA Coastal Services Center
Benthic Terrain Modeling Algorithms
and Web Distribution
AAG Annual Meeting, Denver
April 8, 2005Photo by
National Marine Sanctuaries
Map courtesy of NOAA National Marine Sanctuary System
Maps courtesy of National Park of American Samoa
Artwork by Jayne Doucette, Woods Hole Oceanographic Institution
By former OrSt grad student Emily Larkin
FBNMS: Some Major Issues• Natural & human impacts
– Crown-of-thorns invasion, hurricanes, bleaching– Illegal fishing, sewage outfall
Photos courtesy of NOAA National Marine Sanctuary System
FBNMS cont. & Research ??s• Prior to 2001…
– Sanctuary largely unexplored below depths of ~30-60 m
– no comprehensive documentation of the plants, animals, and submarine topography.
• Little is known of tropical “twilight zone” – shelf-edge (50-120 m deep) of coral reef habitats
throughout the world
• Best combo of terrain analysis techniques?• Extension of satellite-based scheme
– What is viable classification acoustically?
OrSt & USFMultibeam Surveys to date
By OrSt grad student Emily Lundblad
Shallow Multibeam(May 2001, November 2002)
• Kongsberg-Simrad EM-3000• Fans out 121 beams at 130 deg.• Swaths 3-4 times water depth• Depths in 3-150 m range at survey
speeds of 3-12 knots• cm-resolution w/ dGPS
By OrSt grad student Emily Larkin
Fagatele Bay National Marine Sanctuary, 2001 bathy
Bathymetric Position Index(from TPI, Jones et al., 2000; Weiss, 2001; Iampietro & Kvitekk, 2002)
Measure of where a point is in the overall land- or “seascape”Compares elevation of cell to mean elevation of neighborhood
(after Weiss 2001)
Algorithm compares each cell’s elevation to the mean elevation of the surrounding cells in an annulus or ring.
bpi<scalefactor> = int((bathy - focalmean(bathy, annulus, irad, orad)) + .5)
Bathymetric Position Index
-3m-
|---2---| |---------4-------|
resolution = 3 m
irad = 2 cells (6 m)
orad = 4 cells (12 m)
scalefactor = resolution * orad = 36 m
• Negative bpi = depression
• Positive bpi = crest
• Zero bpi = constant slope or flat
BPI Zone and
Structure
Classification
Flowchart
Emily Lundblad, OrSt M.S. Thesis
Emily Lundblad, OrSt M.S. Thesis
Fish Abundance & BPI
Courtesy of Pat Iampietro, CSU-MB, ESRI UC 2003
Benthic Habitat Pilot Areas, DMWR
2005 HURL Sub & ROV surveys
Ka‘imikai-o-Kanaloa Pisces IV or V
RCV-150
Rugosity• Measure of how rough or bumpy a surface is, how convoluted and complex• Ratio of surface area to planar area
Graphics courtesy of Jeff Jenness, Jenness Enterprises, and Pat Iampietro, CSU-MB
Surface area based onelevations of 8 neighbors
3D view of grid on the left Center pts of 9 cells connectedTo make 8 triangles
Portions of 8 triangles overlapping center cellused for surface area
Emily Lundblad, OrSt M.S. Thesis
Link toSamoanversion of site
Zoom tostudy area
Links to help, data download and info pages
Active tool display
OverviewMap
American Samoa Benthic Terrain American Samoa Benthic Terrain ViewerViewerscallywag.science.oregonstate.edu/website/AmSamoa/viewer.htm… or via dusk.geo.orst.edu/djl/samoa
http://dusk.geo.orst.edu/djl/samoa
Samoan Collaborations & Products
• OSU, NOAA & AS GIS User Group
– Benthic classifications for benthic habitat/MPAs– American Samoa Benthic Terrain Viewer– AS Marine/Coastal Bibliographic Tool– On-island workshops in September 2004– Benthic Terrain Modeler (ArcGIS 8.x/9.x tool)– 3D Visualizations and movies in Fledermaus
• Other work– NOAA Coral Reef Ecosystem Division Mapping – Duke U. Coral reef ecosystem studies
For more information …dusk.geo.orst.edu/djl/samoa
Image courtesy of FBNMS
Structure Classification Decision Tree
Emily Lundblad, OrSt M.S. Thesis