Abstract: BATHY30 is a raster data set of bathymetry and intertidal cover types for the Gulf of Maine developed by the U.S. Fish & Wildlife Service; Gulf of Maine Program. Sounding data was used in deeper areas to generate a relatively coarse resolution bathymetry grid. Finer spatial resolution around inshore features were achieved by use of tidal exposure classifications described from aerial photography (e.g., "regularly flooded, irregularly exposed, irregularly flooded") in the USFWS National Wetland Inventory data sets, channels and tidal flats mapped from photography in Maine's Coastal Marine Geologic Environments (CMGE), and Massachusetts orthophoto wetlands maps. These classes were not translated into absolute elevations, but instead were coded as to position within the intertidal zone, and the general cover type (e.g., high marsh, lower intertidal flats, etc.), which may convey useful ecological information. Where near shore subtidal bathymetry were inadequate, the grid was 'patched' using grids developed from scanned NOAA charts. For more information about the USFW Gulf of Maine Program and a CD of data from the Gulf of Maine Watershed Habitat Analysis plus supplemental information about BATHY30 see: http://gulfofmaine.fws.gov/ and http://r5gomp.fws.gov/gom/habitatstudy/metadata/gombathydoc.htm.
Purpose: This information is meant to be used for habitat protection in the Gulf of Maine watershed as identified by the U.S. Fish & Wildlife Service.
Supplemental Information: BATHY30 is available as a single raster in GRID format from the Maine GIS SDE server. An ArcGIS .lyr file to assist users in applying the correct legend information is available in the Maine GIS final data directory /home11/crypt83/layers/bathy30.lyr. The GRID, a color embedded GeoTIFF, two .jpgs views, and an ArcGIS .lyr file bathy30.lyr, are available from the Maine GIS Data Catalog at http://megis.maine.gov/catalog/catalog.asp. Two .jpeg files are available, for a quick color view of the coded classification. These data are also available from USFWS on CD, see point of contact below.

Progress: Complete
Update Frequency: none planned

Theme Keywords: ISO Keyword Thesaurus, imageryBaseMapsEarthCover, elevation, oceans, Maine GIS Thesaurus-Theme, water depth, bathymetry, estuarine
Place Keywords: Maine, New Hampshire, Gulf of Maine, Massachusetts, United States

Access Constraints: Secondary distribution by permission only. Any secondary distribution must have this documentation appended.
Usage Constraints: Users must assume responsibility in determining the usability of this data for their purposes. Digital maps retain the accuracy and currentness of their source materials. The best use of data mapped at scales of 1:500,000 and 1:250,000 is in statewide planning and studies; at 1:100,000 in regional planning and studies; at 1:62,500 and 1:24,000 in detailed studies and local planning; and at 1:12,000 and 1:5,000 or larger scales in parcel level studies and detailed local planning. Please check sources, scale, accuracy, currentness and other available information.