Quick link to the Shallow-Water Benthic Habitat products of the Main Hawaiian Islands – 2007
Quick link to the Shallow-Water Benthic Habitat products of the Main Hawaiian Islands – 2003
Objectives CCMA's Biogeography Branch completed an investigation in 2007 to consistently and comprehensively map the distribution of coral reefs and other benthic habitats throughout the main Hawaiian Islands. The product includes the development of a web site and DV which provides access to digital geographic information system (GIS) data, maps, and imagery depicting the location and distribution of shallow-water seafloor habitats the main Hawaiian Islands. Completion of this project represents a major milestone towards completion of the U.S. Coral Reef Task Force's recommendation to develop shallow-water coral reef ecosystem maps for all U.S. waters. This is the fifth set of major coral reef ecosystem maps produced with support from NOAA/National Ocean Service's (NOS) Coral Reef Conservation Program.
The digital habitat maps can be downloaded from the main Hawaiian Islands website. In addition to digital/georeferenced benthic maps and metadata, digital/georeferenced mosaics of satellite imagery, ground validation data, accuracy assessment data, ground control data, an ArcGis Habitat Digitizer Extension, printable maps, and a methods manual are also available. Thirty-two distinct benthic habitat types (i.e., 4 major and 14 detailed geomorphological structure classes; 8 major and 3 detailed biological cover types) within 13 zones were digitally mapped in GIS (geographic information system) using heads-up visual interpretation of orthorectified satellite imagery. Assessment of these maps indicates that a high degree of thematic and spatial accuracy was achieved. Excellent accuracy, detailed documentation of methodology, and inclusion of a wide range of potential users during all phases of map production has resulted in a suite of products designed to accommodate a broad spectrum of interest groups, and at the same time, complete the project over a 24 month time period. Benthic features were mapped that covered an area1, 310 km2. In all, 387 km2 of unconsolidated sediment, 288 km2 of emergent vegetation, and 915 km2 of coral reef and colonized hardbottom were mapped.
Detailed attention was placed on thematic accuracy (correctly classified habitats) and the geopositional accuracy of map polygons (correct spatial coordinates). Although very small features such as individual coralheads of one meter in size are visible in the airborne imagery, only continuous habitats greater than one acre in size were individually delineated to ensure that maps were completed within a reasonable time frame. The overall thematic accuracy was 98% for the major structure, 90% for the detailed structure, 92% for the major biological cover, and 93.6% for the detailed biological cover classifications. The location of the habitat polygons is generally within three meters of their correct coordinates on the Earth. The georeferenced imagery enables managers and scientists to have the ability to delineate smaller features and modify the classification scheme for their specific project requirements.
|Photo credits: Biogeography Branch|
Reports and Publications
Digital Elevation Models and Bathymetry
Completed: 2002 - 2007
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