High-Resolution Shoreline Map Data for Tidewater Maryland

      These are vector format maps. Unlike raster images, they can be rescaled without distortion.  The maps were created in ArcGIS 8.3 and consist of polyline segments.  The dates of these shorelines are fairly recent, ranging from 1988 to 1995.  Three file formats are available:  Autodesk's Drawing Exchange Format (.DXF), ESRI's Shapefile (.SHP) and Arc Export (.E00) formats.  These are widely accepted vector data standards and are used by programs such as AutoCAD, ArcGIS, ArcInfo, CorelDraw, Adobe Illustrator, JASC's Paint Shop Pro, Bryce 3D, 3D Studio Max, and many Intergraph programs.  The .shp file format contains shoreline attribute data.
     A complete metadata file accompanies each file.  The metadata describe map projections, attributes, compilation procedures and all other critical parameters necessary to the proper use of the data.  A summary of the metadata is presented at the end of the table below.
      To download data click on the desired file format in the table below. Files have been compressed with Winzip to decrease download times.  You will not be able to view the files on-line.

Anne Arundel

      In 2000, the Maryland Geological Survey (MGS) was awarded a Coastal Zone Management grant to complete the acquisition of a recent (ca. 1990) digital shoreline for the coastal regions of Maryland -- the Chesapeake Bay, its tributaries, the coastal bays, and the Atlantic coast.  MGS contracted the services of EarthData International, Inc. (EDI), currently of Frederick, Md., to extract shorelines from an existing wetlands delineation, which was based on photo interpretation of 3.75-minute digital orthophoto quarter quads (DOQQs).  In areas where a wetlands coverage was not yet available, EDI interpreted shorelines directly from the orthophotography.   DOQQ registration (Maryland State Plane Coordinate System, NAD 83, meters) was transferred automatically to the shoreline vectors.  Following shoreline extraction or interpretation, EDI assigned attributes to the vectors based on shoreline type: beach, vegetated, structure, or water’s edge. 
     The data set contains recent shoreline vectors for sixteen coastal counties and Baltimore City, with assigned shoreline types.  The vectors represent shoreline positions between the years 1988 and 1995.

Spatial Reference Information:

• Map Projection Name: Lambert Conformal Conic
• Grid Coordinate System Name: State Plane Coordinate System 1983
• SPCS Zone Identifier: 1900 (Maryland)
• Planar Distance Units: meters
• Horizontal Datum Name: North American Datum of 1983
• Ellipsoid Name: Geodetic Reference System 80
• Semi-major Axis: 6,378,137 meters
• Denominator of Flattening Ratio: 298.257
• Depth Datum Name: The aerial photography from which the DOQQs were developed was not tide-coordinated.  Therefore, shorelines in this data set does not represent a consistent vertical datum.

Shoreline Attributes:

• beach
• vegetated
• structure
• water’s edge

     All four categories are linear features, except “beach,” which, if sufficiently wide, can be both linear and polygonal.  Shorelines were merged into 7.5-minute quadrangles, provided that the aerial photography on which the DOQQs were based was flown in the same year. 
     Please see the complete metadata online or attached to each  downloaded data file.