ReefGIS :: Dataset Definitions

Physical Features

Place Names
Place Names	A list of reef-relevant place names was compiled by ReefBase. This list inlcludes: cities, towns, bays, straits, coral reefs, dive sites and other types of locations, and was compiled using a variety of sources.

Countries
Countries	The country data layer originally comes from the Vector Map (VMap) Level 0, by the National Imagery and Mapping Agency (NIMA). Vector Map (VMap) Level 0 is an updated and improved version of the Digital Chart of the World (DCW®). The VMap Level 0 database provides worldwide coverage of vector-based geospatial data at 1:1,000,000 scale.

Topography

Land topography data originates from the The Global Land One-kilometer Base Elevation (NOAA, NGDC: GLOBE) digital elevation model. It provides 30 arc second gridded elevation data at 1 km resolution. In ReefBase GIS, the topography-layer (as well as bathymetry) is turned off by default to improve performance. If you want to produce more visually attractive maps, you should click the "Show/Hide Topography" button in the map. For full metadata on GLOBE, please click here.

Bathymetry

The bathymetry (ocean depth) data originates from National Geophysical Data Center TerrainBase Global DTM Version 1.0. This data represent an estimate of depth for each 5-minute cell (~10km horizontal resolution). In ReefBase GIS, the bathymetry-layer (as well as topography) is turned off by default to improve performance. If you want to produce more visually attractive maps, you should click the "Show/Hide Topography" button in the map. For full details on TerrainBase, please click here.