High Resolution Shoreline Map Data for Tidewater Maryland
|contact: Bob Conkwright (firstname.lastname@example.org)|
|PLEASE NOTE: These data are for illustration purposes only. Do not use these documents for navigation, legal purposes, or any critical applications. They were created only to illustrate our publications and are not accurate enough to be used for any other purposes.|
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.
|Click on a county to see a thumbnail preview of the vector shoreline map.||County / City||format (file size, kilobytes)|
|dxf (518)||shp (1,064)||e00 (693)|
|Baltimore||dxf (192)||shp (384)||e00 (273)|
|Baltimore City||dxf (68)||shp (123)||e00 (94)|
|Calvert||dxf (368)||shp (735)||e00 (508)|
|Caroline||dxf (146)||shp (277)||e00 (187)|
|Cecil||dxf (117)||shp (221)||e00 (170)|
|Charles||dxf (312)||shp (613)||e00 (450)|
|Dorchester||dxf (1,712)||shp (3,411)||e00 (2,236)|
|Harford||dxf (353)||shp (687)||e00 (464)|
|Kent||dxf (339)||shp (655)||e00 (452)|
|Prince Georges||dxf (246)||shp (474)||e00 (361)|
|Queen Annes||dxf (574)||shp (1,147)||e00 (755)|
|St. Marys||dxf (1,363)||shp (2,773)||e00 (1,891)|
|Somerset||dxf (2,312)||shp (4,604)||e00 (2,924)|
|Talbot||dxf (818)||shp (1,674)||e00 (1,149)|
|Wicomico||dxf (642)||shp (1,260)||e00 (818)|
|Worcester||dxf (999)||shp (1,981)||e00 (1,223)|
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:
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.