Development of an elevation database for the U.S. coastal zone
Grids that integrate land and seafloor elevations are needed by planners using LIS/GIS software to manage the U.S. coastal zone which includes the country's 200-mile offshore limit. The National Geophysical Data Center is addressing this need by assembling a gridded database that merges the U.S. Geological Survey 3-arc-second DEMs with a vast compilation of hydrographic soundings collected by the National Ocean Service and various academic institutions. This paper describes how the database is being constructed, using newly completed and now available grids of the eastern U.S. coastal zone (extending from Maine to Georgia) as an example. The paper also describes the novel software that accompanies the grids on CD-ROM. This software allows the user to navigate the CD-ROM, view grid images, and modify the grids for importation into GIS/LIS applications.