Benthic Habitat Data

Bathymetry

Zipped data files contain 1) grid data file (GMT or ASCII), 2) high-res JPG of image, and 3) explanatory metadata text file (identical to linked file listed below).
* Ikonos imagery & USGS Digital Ortho Quarter Quads NOT included with download.

10m grid data
10m grid data files

CNMI-Guam: Pagan Island

[ Bathymetry | Backscatter | Optical Validation | Geomorphology ]

Gridded Geomorphology

Download 10 meter grid:
Substrate, Slope, Rugosity, BPI Structures, BPI Zones

Click here for a Discussion of Geomorphological Layers

Zipped data files contain 1) Arc ASCII file, 2) layer (.lyr) file for symbology, 3) high-res JPG of image, and 4) explanatory metadata text file (identical to linked file listed below).

Substrate, Hard bottom vs. Soft bottom - 10 meter grid

Substrate :This is a preliminary product derived from an unsupervised classification of multibeam bathymetric data derivatives and multibeam backscatter data. Cell values reflect whether the seafloor is hard or soft. Please see the metadata for additional information.

Image map of Pagan substrate.

This map includes both the Simrad em3002d and Reson 8101 substrate data sets.
Download this image as a high-res JPG or PDF

Hard vs. Soft substrate classification data files

GeoTIFFs derived separately from Simrad em3002d and Reson 8101 backscatter:

Top of the page

Slope - 10 meter grid

Slope: Cell values reflect the maximum rate of change (in degrees) in elevation between neighboring cells. Slope was derived with the ArcGIS Spatial Analyst extension.

Image map of Pagan slope.

Download this image as a high-res JPG or PDF

Slope data files
Top of the page

Rugosity - 10 meter grid

Rugosity: Cell values reflect the surface area and (surface area) / (planimetric area) ratio for the area contained within that cell’s boundaries. They provide indices of topographic roughness and convolutedness. (Jenness 2003)

Image map of Pagan rugosity.

Download this image as a high-res JPG or PDF

Rugosity data files
Top of the page

BPI Structures - 10 meter grid

BPI Structures: Derived from two scales (20 & 250) of BPI; slope; and depth. Three ranges of slope defined flats, slopes and near vertical: x < 5; 5 < x < 70. Depth alone, in this case, is added only to separate flat structures into shelf (<30 m) and broad flat (>30 m) environments (depths based on SCUBA limits).

Figure giving visual description of BPI Structure classes.

A visual description of BPI Structure classes (Click image for larger view.)

Image map of guam BPI Structures.

Download this image as a high-res JPG or PDF

BPI Structures data files
Top of the page

BPI Zones - 10 meter grid

BPI Zones: Derived from a broad scale (250) BPI grid and slope. Two ranges of slope defined flats and slopes: x < 5 and 5 < x < 70.

Image map of guam BPI Zones.

Download this image as a high-res JPG or PDF

BPI Zones data files
Top of the page