Vector Map Metadata
| contact: Stephen Van Ryswick (stephen.vanryswick@maryland.gov) | 
1. Identification Information
1.1 Citation
					8.1 Originator: Maryland Department of Natural Resources,	Chesapeake Bay & Watershed
					Programs, Resource Assessment	Service, Maryland Geological Survey (MGS)
					8.2 Publication Date: 2003
					8.4 Title: Recent (1988-1995) Maryland Shorelines	with Erosion Rate Attributes
					8.5 Edition: 1
					8.6 Geospatial Data Presentation Form: vector digital	data
					8.8 Publication Information
					8.8.1 Publication Place: Baltimore, Maryland, USA
					8.8.2 Publisher: Maryland	Department of Natural	Resources, Chesapeake Bay & Watershed
					Programs, Resource Assessment	Service, Maryland Geological Survey (MGS)
					8.9 Other Citation Details: CD-ROM CoErosionRates
					8.10 Online Linkage: http://www.mgs.md.gov
					
 1.2 Description
					1.2.1 Abstract:  
					      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.  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. 
					      MGS used the shorelines to create a series of Shoreline
					Changes maps.  In doing so, MGS erased the landward edge of beach polygons, leaving
					the	seaward edge intact as a linear feature.
					      The Geographic Information Services Division of the
					Maryland Department of Natural Resources (DNR) merged the shorelines for all of the
					7.5-minute quadrangles into	a single, statewide coverage.
					      MGS, working collaboratively with Towson University’s
					Center for Geographic Sciences (CGIS), subsequently used the recent shorelines, along
					with historical ones, as input into a U.S. Geological Survey (USGS) program, the Digital
					Shoreline Analysis	System	(DSAS)	(Danforth and Thieler, 1992; Thieler and others, 2001).  DSAS
					determines linear rates of shoreline change (erosion or accretion) along closely spaced,
					shore-normal	transects.  Based on DSAS output, the collaborators assigned the following
					erosion rate categories as attributes to the recent shoreline, clipped by county from
					the	statewide coverage: 
					
- High erosion rate (more than 8 ft/yr)
- Moderate erosion rate (4-8 ft/yr)
- Low erosion rate (2-4 ft/yr)
- Slight erosion rate (0-2 ft/yr)
- No change
- Accretion
- Protected
- Unknown
- No Data
     The data set contains recent shoreline vectors for
					sixteen coastal counties and Baltimore City (see Appendix 1), assigned both shoreline
					type and erosion rate attributes.  The vectors represent shoreline positions between
					the years 1988 and 1995.
					      The metadata was originally written to document the
					recent shoreline vectors, interpreted, directly or indirectly, from DOQQs and merged
					by	7.5-minute quadrangle (see Appendix	2).  It was amended to include information about
					the erosion rate attributes later assigned to the county shorelines.
					
 1.2.2 Purpose:  This data set complements a set of historical digital shorelines
					for the Maryland reaches of the Chesapeake Bay, the coastal bays, and the Atlantic
					coast (See Section 1.14).  That data set spans the	period 1841-1977.  The two data
					sets are being used to update a series	of Shoreline Changes maps and to determine
					coastal land loss during the last	half of the 20th century.  Other State
					agencies will be able to use this data to analyze and update land loss information,
					analyze historical erosion trends, and assess the extent and magnitude of shore erosion
					on a regional	geographic basis.  In particular, the availability of up-to-date shoreline
					change data will support the design and implementation of shore protection projects
					and the development	of a comprehensive shore erosion control plan. 
					1.2.3 Supplemental Information:  This document serves as metadata for
					recent (ca. 1990) shoreline vector files, assigned erosion rate attributes, for Baltimore
					City and 16 coastal counties in	Maryland.
				
See appendices:
Appendix 1: Bounding Coordinates of Maryland’s Coastal Counties and Baltimore City
Appendix 2: Shoreline Dates, by Quadrangle
Appendix 3: Constituent Quadrangles and Attributed Shoreline File Size, by County
Related publications:
Hennessee, L., 2000, Acquiring a modern digital shoreline for Maryland from recent (1988-1995) orthophotography: Maryland Geological Survey, Baltimore, Md., Coastal and Estuarine Geology File Report No. 00-7.Hennessee, L.H., Valentino, M.J., Lesh, A.M., and Myers, L., 2002, Determining shoreline erosion rates for the coastal regions of Maryland (Part 1): Maryland Geological Survey File Report No. 02-04, Baltimore, Md., 32 p.
Hennessee, L.H., Valentino, M.J., and Lesh, A.M., 2003, Determining shoreline erosion rates for the coastal regions of Maryland (Part 2): Maryland Geological Survey File Report No. 03-01, Baltimore, Md., 53 p.
Hennessee, L.H., Valentino, M.J., and Lesh, A.M., in prep., Updating Shore Erosion Rates in Maryland: Maryland Geological Survey File Report No. 03-05, Baltimore, Md.
References:
 Conkwright, R.D. (compiler), 1975, Historical	Shorelines Atlas:  Maryland
					Geological Survey, Baltimore, Md.,	4 volumes. 
					Cowardin, L.M., Carter V., Golet, F., and	LaRoe, E., 1979, Classification
					of wetlands and deep water habitats of the	United	States: U.S. Fish and Wildlife
					Service, 103 pp. 
					Danforth, W.W., and Thieler, E.R., 1992, Digital Shoreline Analysis System
					(DSAS)	User’s Guide,	Version 1.0:  U.S. Geological Survey Open-File Report
					92-355,	18 p. 
					Hennessee, L.,	2000a, Metadata:  Historical shorelines, 1841-1976, Chesapeake
					Bay region of Maryland (CD-ROM SCSL_RVC):  Maryland Geological Survey, Baltimore,
					Md. 
					Hennessee, L.,	2000b, Metadata:  Maryland digital shoreline acquisition
						from recent orthophotography:  Recent (ca. 1990) shorelines, coastal regions of Maryland
					(CD-ROM	RecentSL):  Maryland Geological Survey,	Baltimore, Md. 
					Thieler, E.R., O’Connell, J.F., and Schupp, C.A., 2001, The Massachusetts
					Shoreline Change Project: Technical Report 1800s to 1996, U.S. Geological Survey
					Administrative	Report, Woods Hole, MA.
					
 1.3 Time Period of Content
						9 Time Period Information
						9.2 Multiple Dates/Times
						9.2.1 Calendar Date
						9.3 Range of Dates/Times
					9.3.1 Beginning Date: 19880417
					9.3.3 Ending Date: 19950325 – See Appendix 2 – Date	of photography 
					1.3.1 Currentness Reference: The dates on which aerial photography	was flown.  The
					aerial photography was used to create digital orthophoto quarter quads	(DOQQs).  A
					wetlands delineation based on photo interpretation of the DOQQs or the orthophotography
					itself was the	immediate source of the shorelines in the data set.
					
 1.4 Status
					1.4.1 Progress: Complete
					1.4.2 Maintenance and Update Frequency: Irregular
					
 1.5 Spatial Domain
						1.5.1 Bounding Coordinates
					(Bounding coordinates of entire study area; see Appendix 1 for bounding coordinates
					of	individual counties)
					1.5.1.1 West Bounding Coordinate: -77.375°
					1.5.1.2 East Bounding Coordinate: -75.0°
					1.5.1.3 North	Bounding Coordinate: 39.625°
					1.5.1.4 South Bounding Coordinate: 37.875°
					
 1.6 Keywords
						1.6.1 Theme
					1.6.1.1 Theme Keyword Thesaurus: Global Change Master Directory List of
					Valid Keywords:  Earth	Science Parameters Valid Keywords (CATEGORY > TOPIC > Term > Variable) http://gcmd.gsfc.nasa.gov/valids/
					1.6.1.2 Theme Keyword: EARTH	SCIENCE > OCEANS > Coastal Processes > Beaches
					1.6.1.2 Theme Keyword: EARTH	SCIENCE > OCEANS > Coastal Processes > Erosion
					1.6.1.2 Theme Keyword: EARTH	SCIENCE > OCEANS > Coastal Processes > Estuaries
					1.6.1.2 Theme Keyword: EARTH	SCIENCE > OCEANS > Coastal Processes > Shoreline
					Displacement
					1.6.1.2 Theme Keyword: EARTH SCIENCE > OCEANS > Coastal Processes > Shorelines
					1.6.1.1 Theme Keyword Thesaurus: None
					1.6.1.2 Theme Keyword: vector
					1.6.1.2 Theme Keyword: county
					1.6.1.2 Theme Keyword: 7.5-minute quadrangle
					1.6.1.2 Theme Keyword 3.75-minute quadrangle
					1.6.2 Place
					1.6.2.1 Place Keyword Thesaurus: U.S. Geological Survey, Index to Topographic
					and Other Map Coverage: Maryland, Delaware, and District of Columbia (38076-H4-MI-99X),
					22 p.
					1.6.2.2 Place Keyword: Maryland (MD)
					1.6.2.2 Place Keyword: Chesapeake Bay
					1.6.2.2 Place Keyword: Delaware (DE)
					1.6.2.2 Place Keyword: District of Columbia (DC)
					1.6.2.2 Place Keyword: Virginia (VA)
					1.6.2.2 Place Keyword: See Appendix	1 – County, and	Appendix 2 - Quadrangle
					
1.7 Access Constraints: None
 1.8	Use Constraints: The DOQQs from which the shorelines were interpreted
					meet National Map Accuracy Standards at the production scale of 1:12,000 using the
					American Society for Photogrammetry and Remote Sensing	(ASPRS) method.  Consider the
					scale in displaying and using the	vectors.  Displaying the vectors at scales larger
					than those of the	source documents is considered bad practice. 
					     See Section 2.4.1.1 Horizontal Positional Accuracy Report
					for positional inaccuracies	in the data set.
					     The aerial photography from which the DOQQs were developed
					was not	tide-coordinated.  Therefore, shorelines in this data set do not represent
					a consistent vertical datum.
					
 1.9	Point of Contact
						10	Contact Information
						10.1	Contact Person Primary
					10.1.1	Contact Person: Lamere Hennessee
					10.1.2	Contact Organization: Maryland	Geological Survey
					10.4	Contact Address
					10.4.1	Address Type: mailing and physical	address
					10.4.2	Address: 2300 St. Paul Street
					10.4.3	City: Baltimore
					10.4.4	State or Province: Maryland
					10.4.5	Postal Code: 21218-5210
					10.4.6	Country: USA
					10.5	Contact Voice Telephone: (410) 554-5519
					10.7	Contact Facsimile Telephone: (410)	554-5502
					10.8	Contact Electronic Mail Address: lhennessee@dnr.state.md.us
					10.9	Hours of Service: 9:00	a.m. - 5:00 p.m. EST
					
1.11 Data Set Credit: Partial funding for this data set was provided by the National Oceanic and Atmospheric Administration (NOAA) and made available through the Maryland Coastal Zone Management Program of the Department of Natural Resources (CZM). In particular, shorelines were extracted or photo interpreted under NOAA Award No. NA87OZ0236, CZM Grant M00-050 CZM 031; erosion rate attributes were assigned under NOAA Award No. NA17OZ1124, CZM Grant 14-03-891 CZM 046. The views expressed herein are those of the authors and do not necessarily reflect the views of NOAA or any of its sub-agencies.
1.13 Native Data Set Environment:
- Software: ArcGIS 8.2
- Operating system: Microsoft Windows 2000
- File size: Less than 4 Mb per county; for exact sizes, see Appendix 3 - File size.
- File format: ESRI Arc coverage
1.14	Cross Reference
					8	Citation Information
				8.1	Originator: Maryland Geological Survey
				8.2	Publication Date: 2003
				8.4	Title: Determining Shoreline Erosion Rates for the Coastal Regions of Maryland
				(Part 2)
				8.6	Geospatial Data Presentation Form: vector digital data
				8.8	Publication Information
				8.8.1	Publication Place: Baltimore, Maryland, USA
				8.8.2	Publisher: Maryland Geological Survey
				8.9	Other Citation Details: CD-ROM SLChangeRatesAll 
				1.14	Cross Reference
					8	Citation Information
				8.1	Originator: Maryland Geological Survey
				8.2	Publication Date: 2000
				8.4	Title: Historical Shorelines, 1841-1976: Chesapeake Bay Region of Maryland
				8.6	Geospatial Data Presentation Form: vector digital data
				8.8	Publication Information
				8.8.1	Publication Place: Baltimore, Maryland, USA
				8.8.2	Publisher: Maryland Geological Survey
				8.9	Other Citation Details: CD-ROM SCSL_RVC 
				1.14	Cross Reference
					8	Citation Information
				8.1	Originator: Maryland Geological Survey
				8.2	Publication Date: 2001
				8.4	Title: Shoreline Changes maps
				8.6	Geospatial Data Presentation Form: map
				8.8	Publication Information
				8.8.1	Publication Place: Baltimore, Maryland, USA
				8.8.2	Publisher: Maryland Geological Survey
				
2 Data Quality Information
2.1 Attribute Accuracy: Accuracy of the shoreline type attributes was not assessed.CGIS checked the accuracy of the erosion rate classification by displaying both the shore-normal transects and the shoreline, color-coded, respectively, by erosion rate (ft/yr) and erosion rate category (high, moderate, low, etc.). If the color of the transects matched the color of the associated shoreline segment, CGIS accepted the erosion rate classification. Otherwise, CGIS changed the classification.
2.2 Logical Consistency Report: EDI checked logical consistency through a series of quality assurance/quality control (QA/QC) procedures, reported in Section 2.5.2 Process Step (interpretation/extraction of shorelines).
2.3 Completeness Report: The area covered includes 125 7.5-minute quadrangles lying at least partially within Baltimore City or one of the 16 coastal counties of Maryland. (Appendix 2 lists the quadrangles for which shoreline rates-of-change were calculated. Appendix 3 lists the constituent quadrangles of each county.) Shorelines located in out-of-state areas, such as the Virginia side of the Potomac River, were excluded.
In digitizing historical shorelines from hard copy maps, MGS had adopted an operational definition of the headward extent of a stream - the point at which the stream was represented on the map by a single line rather than a double line delineating opposite stream banks. That point, dependent as it is on the scale of the map, does not necessarily represent the head of tide. A similar criterion was used in extracting the 1990 shoreline. To the extent that the contractor could fit a double line on photography displayed at a scale of 1:24,000, the shoreline was extracted. Reaches upstream of that point were excluded. Again, the headward extent of a digitized stream does not necessarily correspond with head of tide.
Shorelines in the 1990 data set bounded several different wetlands classifications (Cowardin et al., 1979):
- E 1 UB L (Estuarine -- Subtidal -- Unconsolidated bottom -- Subtidal)
- E 2 US M (Estuarine – Intertidal – Unconsolidated shore – Irregularly exposed)
- E 2 US N (Estuarine – Intertidal – Unconsolidated shore – Regularly flooded)
- E 2 US P (Estuarine – Intertidal – Unconsolidated shore – Irregularly flooded)
- M 2 US M (Marine – Intertidal – Unconsolidated shore – Irregularly exposed)
- M 2 US N (Marine – Intertidal – Unconsolidated shore – Regularly flooded)
- R 1 UB V (Riverine -- Tidal -- Unconsolidated bottom -- Permanent tidal (tidally influenced, freshwater system)
- R 2 UB 8 – (Riverine -- Lower perennial -- Unconsolidated bottom -- Eusaline)
In addition to designating UB L and UB V as water, M 2 or E 2 US (Unconsolidated shore) M (Irregularly flooded) or N (Regularly flooded) classifications were considered water, given that those areas were more likely to be under water than above. E 2 US P (Irregularly flooded) was considered upland, given that those areas were more likely to be above water than under. In assigning rate-of-change attributes, MGS and CGIS devised and applied a number of rules, which are summarized below:
- Classify shoreline segments of the shoreline type “structure” as “protected.”
- When adding nodes to distinguish between shoreline reaches with different rates of change, insert nodes only after the occurrence of a series of four or more similarly colored transects. For example, along an extensive reach that has experienced moderate rates of erosion, interrupted by two adjacent transects characterized by high erosion rates, classify the entire stretch of shoreline as “moderate.” If, instead of two high-rate transects, six high-rate transects occur in a row, insert nodes on either side of the six transects, and classify that shoreline reach as “high.”
- If shorelines are so complex that it is difficult to distinguish between the two shoreline years or to see that they are properly positioned, assign the erosion rate category “Unknown.” This problem is particularly common in marshy areas and/or along minor tributaries of dubious positional accuracy. A common manifestation of the latter is that one bank of the tributary is erosional along its entire length, while the opposite bank is accretional.
- For reaches lacking transects, estimate rates based on the relative positions of the two shorelines. This situation is common along points of land projecting into the water.
- Classify stretches represented by a single shoreline as “No Data.”
- If the two shorelines interweave over an extended reach, with little lateral displacement, classify the stretch as “No Change.”
2.4	Positional Accuracy
					2.4.1	Horizontal Positional Accuracy
				2.4.1.1	Horizontal Positional Accuracy Report:  The DOQQs meet
				National Map Accuracy Standards at the production scale of 1:12,000, using the American
				Society for Photogrammetry	and Remote Sensing (ASPRS) method.  The contractor who
				produced the DOQQs provided a detailed aerotriangulation report for each production
				area (See	DOQQ metadata at the web	site listed in Section 2.5 Lineage).
				      The production of accurately georeferenced DOQQs depends
				on sufficient ground control.  In open water, ground control is necessarily lacking,
				because land areas, if they exist at all, are small	and/or	inaccessible.  Two quarter
				quads in the data set, Deal Island NW and Barren Island NE, contain so much open water
				that they are not properly tied to the adjoining tiles, Nanticoke SW and Honga NW,
				respectively.  Consequently, the corresponding linework (shoreline) is not properly
				georeferenced.  The shorelines derived from those two DOQQs are included in the data
				set solely for	the associated attribute (shoreline	type) information.  Their positions
				are	inaccurate. 
2.5	Lineage
					2.5.1	Source Information
					2.5.1.1	Source Citation
					8	Citation Information 
					8.1	Originator: Maryland Department of Natural Resources, Chesapeake and Coastal
					Watershed Service, Geographic Information Services Division
					8.2	Publication Date: 1988-1995
					8.4	Title: Digital Orthophoto Quarter Quads (DOQQs)
					8.6	Geospatial Data Presentation Form: raster digital data
					8.8	Publication Information
					8.8.1	Publication Place: Annapolis, Maryland, USA
					8.8.2	Publisher: Maryland Department of Natural Resources, Chesapeake and Coastal
					Watershed Service, Geographic Information Services Division
					8.9	Other Citation Details: For complete metadata for this source, see the
					following web site: http://www.msgic.state.md.us/techtool/samples 
					2.5.1.2	Source Scale Denominator: 12000 
					2.5.1.3	Type of Source Media: CD-ROM 
					2.5.1.4	Source Time Period of Content
						9	Time Period Information
					9.2	Multiple Dates/Times – See Appendix 2 – Date	of photography
					9.3	Range of Dates/Times
					9.3.1	Beginning Date: 19880417
					9.3.3	Ending Date: 19950325 
					2.5.1.4.1	Source Currentness Reference: date on which aerial photography was
					flown 
					2.5.1.5	Source Citation Abbreviation: Digital Orthophoto Quarter Quads (DOQQs) 
					2.5.1.6	Source Contribution: Photo interpretation of the DOQQs resulted in
					the Maryland DNR Wetlands Inventory, from which most of the recent shorelines were
					extracted.  In areas where a wetlands coverage was not yet available, EDI interpreted
					shorelines directly from the	orthophotography.   
					2.5.1.1	Source Citation
						8	Citation Information
					8.1	Originator: Maryland Department of Natural Resources, Chesapeake and
					Coastal Watershed Service, Geographic Information Services Division
					8.2	Publication Date: 1988-1995
					8.4	Title: Maryland DNR Wetlands Inventory}
					8.6 Geospatial Data Presentation	Form: vector digital data
					8.8	Publication Information
					8.8.1	Publication Place: Annapolis, Maryland, USA
					8.8.2	Publisher: Maryland Department of Natural Resources, Chesapeake and Coastal
					Watershed Service, Geographic Information Services Division
					8.9	Other Citation Details: For complete metadata for this source, see the
					following website: http://www.msgic.state.md.us/techtool/samples
					2.5.1.2	Source Scale Denominator: 12000 
					2.5.1.3	Type of Source Media: CD-ROM 
					2.5.1.4	Source Time Period of Content
						9	Time Period Information
					9.2	Multiple Dates/Times – See Appendix 2 – Date	of photography
					9.3	Range of Dates/Times
					9.3.1	Beginning Date: 19880417
					9.3.3	Ending Date: 19950325 
					2.5.1.4.1	Currentness Reference: ground condition on date of photography 
					2.5.1.5	Source Citation Abbreviation: MD DNR wetlands 
					2.5.1.6	Source Contribution: Most of the recent shorelines were extracted from
					the	DNR wetlands inventory, a vector data set interpreted from DOQQs. 
					2.5.1.1	Source Citation
						8	Citation Information
					8.1 Originator: Maryland Department of Natural	Resources, Chesapeake Bay & Watershed
					Programs, Resource Assessment	Service, Maryland Geological Survey (MGS)
					8.2	Publication Date: 2003
					8.4	Title: Determining Shoreline Erosion Rates for the Coastal Regions of Maryland
					(Part 2)
					8.6	Geospatial Data Presentation Form: vector digital data
					8.8	Publication Information
					8.8.1	Publication Place: Baltimore, Maryland, USA
					8.8.2 Publisher: Maryland	Department of Natural	Resources, Chesapeake Bay & Watershed
					Programs, Resource Assessment	Service, Maryland Geological Survey (MGS)
					8.9	Other Citation Details:  CD-ROM	SLChangeRatesAll 2003 
					2.5.1.3	Type of Source Media: CD-ROM 
					2.5.1.4	Source Time Period of Content
						9	Time Period Information
						9.1	Single Date/Time
					9.1.1	Calendar Date: 2003 
					2.5.1.4.1	Source Currentness Reference: publication date 
					2.5.1.5	Source Citation Abbreviation: Transect-based rates of shoreline	change 
					2.5.1.6	Source Contribution: The attribute table associated with almost 250,000
					shore-normal transects, constructed at 20-meter intervals along shore, includes linear
					rates of shoreline change for the ~50-year era ending ca. 1990.  Negative rates indicate
					shoreline retreat,	and positive rates, shoreline advance. 
					2.5.2	Process Step (interpretation/extraction of shorelines; assignment of
					shoreline type attributes) 
					2.5.2.1	Process Description:  Under contract to MGS, EDI extracted
					or interpreted the modern (1988-1995) shoreline directly or indirectly from digital
					orthophotography.  For all but 35 of the quarter quads, EDI extracted the shoreline
					from existing wetlands vectors, previously delineated for the Maryland Department
					of Natural Resources (DNR) over	1:1,000-scale DOQQs.  The DOQQs, in turn, were derived
					from 1:40,000-scale	color infrared (CIR) film.  For the remaining 35 quarter quads,
					the	shoreline was interpreted	directly from the DOQQs.
					     For shoreline vectors extracted from the existing wetlands
					coverage, EDI stripped wetlands vectors of their linear attributes	(line classes).  All
					shorelines and the DOQQ tile boundary were displayed over the DOQQ (raster) from which
					they were originally	interpreted and reassigned attributes.  Shoreline segments were
					classified using	the following four categories: beach, structure, vegetated,	and water’s
					edge.  All	four categories are linear features, except for "beach," which
					can be both	linear and polygonal.  The DOQQ tile boundary was arbitrarily assigned
					one of the	four categories so that it could be extracted with the shoreline	vectors.  Shoreline
					vectors were extracted from the original vector set by line class, using only the four
					shoreline categories. The extracted vectors were then displayed to detect shoreline
					breaks or other	inconsistencies.  Errors were corrected, and shoreline vectors were
					re-extracted.  After extraction, vector sets were cleaned by deleting any extraneous
					lines (non-shoreline vectors) that had mistakenly been assigned one of the four categories
					before extraction.  Beach polygons were attributed at this time, and the DOQQ tile
					boundary was assigned to	a fifth category -unclassified.  The final quality control
					check	consisted of	two steps.  First, each tile (quarter quad) was displayed individually
					to check for unclassified shoreline	vectors.  Second, if the photography on which the
					DOQQs were based was flown in the same year, vectors from adjacent tiles were merged
					into a single, 7.5-minute quadrangle vector set.  Otherwise, multi-year shorelines
					for the same quadrangle were stored as separate objects within the TNTmips project
					(.rvc) file.  Merged vector sets were displayed to check for class consistency (proper
					edge matching) between	adjacent tiles.  Any necessary corrections were made before
					saving the final vector sets.
					      Shorelines derived directly from DOQQs were interpreted
					according to the procedure	outlined in the wetlands inventory metadata.
					      The DOQQs were already georeferenced to the Maryland
					State Plane Coordinate System (North	American Datum of 1983, meters).  Georeferencing
					was transferred	automatically upon delineating either	wetlands or shorelines.
					      MGS subsequently converted beach polygons to line segments
					by removing the landward edge	of the polygon. 
					2.5.2.2	Source Used Citation Abbreviation: MD DNR Wetlands 
					2.5.2.3	Process Date:
						9	Time Period Information
						9.3	Range of Dates/Times
					9.3.1	Beginning Date: 1995
					9.3.3	Ending Date: 2000 
					2.5.2.6	Process Contact (interpretation/extraction of shorelines; assignment
					of	shoreline type attributes)
					10	Contact Information
						10.2	Contact Organization Primary
					10.2.1	Contact Organization: EarthData International of Maryland
					10.2.1	Contact Person: Michelle Hutchinson
					10.4	Contact Address
					10.4.1	Address Type: mailing and physical address
					10.4.2	Address: 7320 Executive Way
					10.4.3	City: Frederick
					10.4.4	State or Province: Maryland
					10.4.5	Postal Code: 21704
					10.4.6	Country: USA
					10.5	Contact Voice Telephone: (301) 948-8550
					10.7	Contact Facsimile Telephone: (301) 963-2064
					10.8	Contact Electronic Mail Address: http://www.earthdata.com
					10.9	Hours of Service: 9:00 a.m. -5:00 p.m. EST 
					2.5.2	Process Step (assignment of rate-of-change categories) 
					2.5.2.1	Process Description:  In collaboration with MGS, Towson	University’s
					Center for Geographic Information Sciences (CGIS) assigned generalized rate-of-change
					categories to recent shoreline vectors, using transect-based erosion rates generated
					by a U.S. Geological Survey (USGS) computer program, the Digital Shoreline Analysis
					System (DSAS).  DSAS constructs	a	50-meter buffer around a series of digital shorelines.  From
					the landward side of the buffer, or baseline, DSAS casts transects at 20-meter intervals,
					perpendicular	to the	baseline.  For each transect, DSAS computes rates of change based
					on all shorelines intersected by the transect, as well as rates for each successive
					pair of shorelines.  If, for example, a transect crosses shorelines from 1850, 1900,
					1950, and 1990, DSAS	output includes rates for the following “eras”: 1850-1900,
					1900-1950,	and 1950-1990.  In assigning erosion rate attributes to the ca. 1990 shoreline,
					MGS	and CGIS used rates based on the most	recent era, that is, the one ending
					in 1988-1995.  Usually, that era spanned approximately 50 years, from the 1940s to
					the	1990s.  In some cases, however, the era was considerably shorter (e.g., 1975-1990)
					or longer	(e.g., 1850-1990).
				   CGIS assigned erosion rate attributes to the recent	shoreline by: 
- Color-coding transects according to previously established rate-of-change categories:
- High – High erosion rate (more than 8 ft/yr)
- Moderate – Moderate erosion rate (4-8 ft/yr)
- Low – Low erosion rate (2-4 ft/yr)
- Slight – Slight erosion rate (0-2 ft/yr)
- Accretion
- Visually grouping similarly colored transects,
- Inserting nodes between transects that differed in color, and
- Assigning the appropriate classification code to the shoreline reach.
     The rules that CGIS followed in the process are described
					in	2.3 Completeness Report. 
					2.5.2.2	Source Used Citation Abbreviation: Transect-based rates of shoreline
					change 
					2.5.2.3	Process Date:
						9	Time Period Information
						9.3	Range of Dates/Times
					9.3.1	Beginning Date: 200304
					9.3.3	Ending Date: 200306 
					2.5.2.6	Process Contact (assignment of rate-of-change categories)
					10 Contact Information
						10.1 Contact Person Primary
					10.1.1 Contact Person: Mary J. Valentino and Ashley	M. Lesh
					10.1.2 Contact Organization: Center for Geographic	Information Sciences
					10.4 Contact Address
					10.4.1 Address Type: mailing and physical address
					10.4.2 Address: Towson University
					10.4.2 Address: 8000 York Road
					10.4.3 City: Towson
					10.4.4 State or Province: Maryland
					10.4.5 Postal Code: 21252-0001
					10.4.6 Country: USA
					10.5 Contact Voice Telephone: (410) 704-3887
					10.7 Contact Facsimile Telephone: (410) 704-3888
					10.9 Hours of Service: 9:00 a.m. -5:00 p.m.	EST 
					2.6	Cloud Cover: 0 (for DOQQs)
					
 3	Spatial Data Organization Information
					3.2	Direct Spatial Reference Method: Vector
					
 4	Spatial Reference Information
						4.1	Horizontal Coordinate System Definition
						4.1.2	Planar
						4.1.2.1	Map Projection
					4.1.2.1.1	Map Projection Name: Lambert Conformal Conic
					4.1.2.1.2	Map Projection Parameters for Lambert Conformal Conic
					4.1.2.1.2.1	Standard Parallel: 38.3
					4.1.2.1.2.1	Standard Parallel: 39.45
					4.1.2.1.2.2	Longitude of Central Meridian: -77.0
					4.1.2.1.2.3	Latitude of Projection Origin: 37.67
					4.1.2.1.2.4	False Easting: 400,000
					4.1.2.1.2.5	False Northing: 0
					4.1.2.2	Grid Coordinate System
					4.1.2.2.1	Grid Coordinate System Name: State Plane Coordinate System 1983
					4.1.2.2.4	State Plane Coordinate System (SPCS)
					4.1.2.2.4.1	SPCS Zone Identifier: 1900 (Maryland)
					4.1.2.4	Planar Coordinate Information
					4.1.2.4.1	Planar Coordinate Encoding Method: coordinate pair
					4.1.2.4.4	Planar Distance Units: meters
					4.1.4	Geodetic Model
					4.1.4.1	Horizontal Datum Name: North American Datum of 1983
					4.1.4.2	Ellipsoid Name: Geodetic Reference System 80
					4.1.4.3	Semi-major Axis: 6,378,137 meters
					4.1.4.4	Denominator of Flattening Ratio: 298.257
					4.2	Vertical Coordinate System Definition
						4.2.2	Depth System Definition
					4.2.2.1	Depth Datum Name: The aerial photography from which the DOQQs were
					developed was not tide-coordinated.  Therefore, shorelines in this data set do not
					represent a consistent	vertical datum.
					
 5	Entity and Attribute Information
						5.1	Detailed Description
						5.1.1	Entity Type
					5.1.1.1	Entity Type Label: Shoreline
					5.1.1.2	Entity Type Definition:  The shoreline, based on photo interpretation,
					is the dividing line between land and	sea.  The DOQQs, the ultimate source of the
					shorelines, were not based on tide-coordinated photography.  Therefore, the shoreline
					vectors do not	represent a consistent vertical datum.
					5.1.1.3	Entity Type Definition Source: Operational definition agreed upon by
					MGS	and EDI
					5.1.2	Attribute
					5.1.2.1	Attribute Label: TYPE_ 
					5.1.2.2	Attribute Definition: Shoreline type, based on photo interpretation
					5.1.2.3	Attribute Definition Source: Classification agreed upon by MGS and
					EDI
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: beach 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Any sandy beach-like area,
					not	including mud flats.  All beaches on this CD-ROM are linear	features.  Originally,
					very narrow beaches were represented as linear features; wider beaches were represented
					as both lines and polygons.  For this exercise, the landward edge of beach polygons
					was erased, leaving a line that	represents the land/water	boundary. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Photo interpretation
					convention 
					5.1.2.4.1.1	Enumerated Domain Value: structure 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Any type of manmade object
					that serves	as the land/water boundary.  Structures include, but are not limited to,
					bulkheads, seawalls, and riprap. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Photo interpretation
					convention 
					5.1.2.4.1.1	Enumerated Domain Value: vegetated 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Any portion of shoreline with
					vegetation, such as marsh, forest, or cropland, as the dominant land cover. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Photo interpretation
					convention 
					5.1.2.4.1.1	Enumerated Domain Value: waters edge 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Any reach of shoreline that
					does not	qualify as beach, structure, or vegetated.  This may include	mud flats. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Photo interpretation
					convention 
					5.1.2.4.1.1	Enumerated Domain Value: unclassified 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Used to identify the DOQQ tile
					boundary	line.  Also used to identify the large polygon(s) enclosed by the DOQQ tile
					boundary line. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and EDI 
					5.1.2	Attribute
					5.1.2.1	Attribute Label: LEVELID (erosion rate code) and associated EROSIONLEVEL
					(erosion rate) 
					5.1.2.2	Attribute Definition: Erosion rate code (LEVELID) and generalized erosion
					rate (EROSIONLEVEL), in feet per year, at which a reach of shoreline has advanced
					or retreated, based on the positions of the two most recent digital shorelines available
					for the reach.  (The date of the later of these two shorelines	is always between	1988-1995.) 
					5.1.2.3	Attribute Definition Source: Classification agreed upon by MGS and
					CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 5; EROSIONLEVEL = High 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline retreat exceeding
					8	ft/yr.  5.1.2.4.1.3 Enumerated Domain Value Definition	Source: Classification
					agreed upon by MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 4; EROSIONLEVEL = Moderate 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline retreat between
					4-8	ft/yr. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 3; EROSIONLEVEL = Low 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline retreat between
					2-4	ft/yr. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 2; EROSIONLEVEL = Slight 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline retreat between
					0.01-2 ft/yr. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 0; EROSIONLEVEL = No Change 
					5.1.2.4.1.2	Enumerated Domain Value Definition: No change in shoreline position
					over	time (-0.01 < EROSION(FT) < 0.01). 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 1; EROSIONLEVEL = Accretion 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline advance exceeds
					0.01	ft/yr. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 6; EROSIONLEVEL = Protected 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline advance or
					retreat not indicated, because shoreline reach is protected (i.e., shoreline type
					=	structure). 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 7; EROSIONLEVEL = Unknown 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline advance or
					retreat not indicated, usually because of obvious inaccuracies in relative positions
					of	shorelines. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: LEVELID = 8; EROSIONLEVEL = No Data 
					5.1.2.4.1.2	Enumerated Domain Value Definition: Rate of shoreline advance or
					retreat	not indicated, because no historic shorelines are available for comparison. 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Classification agreed
					upon by	MGS and CGIS 
					5.1.2	Attribute
					5.1.2.1	Attribute Label: DATE_ 
					5.1.2.2	Attribute Definition: Date of photography, between 1988 and 1995, on
					which	aerial photography was flown.  In month/day /year (MM/DD/YYYY) format in attribute
					table; in year/month/day	(YYYYMMDD) format in Appendix 2. 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: See Appendix 2 – Date of photography 
					5.1.2.4.1.3	Enumerated Domain Value Definition Source: Dates provided by	DNR’s
					Geographic Information Services Division, which acquired the photography. 
					5.1.2	Attribute
					5.1.2.1	Attribute Label: QUADRANGLE 
					5.1.2.2	Attribute Definition: USGS 7.5-minute quadrangle name 
					5.1.2.3 Attribute Definition Source: U.S. Geological Survey, Index to Topographic
					and Other Map Coverage: Maryland, Delaware, and District of Columbia (38076-H4-MI-99X),
					22 p. 
					5.1.2.4	Attribute Domain Values
					5.1.2.4.1	Enumerated Domain
					5.1.2.4.1.1	Enumerated Domain Value: See Appendix 2 – Quadrangle 
					5.1.2.4.1.3 Enumerated Domain Value Definition Source: U.S. Geological Survey,
					Index to Topographic and Other Map Coverage: Maryland, Delaware, and District of Columbia
					(38076-H4-MI-99X), 22 p. 
					5.2	Overview Description
					5.2.1	Entity and Attribute Overview
					The 17 main directories on the CD-ROM, each assigned the full, concatenated name of
					a coastal county or Baltimore City, contain county or city shorelines, ca. 1990, assigned
					both shoreline type and shoreline rate-of-change attributes.  The attribute tables
					associated with the coverages contain a field, LEVELID, linked to the rates table
					(ratestable).  The rates table (Table 1), at the same level in the directory structure
					as the county and city directories, serves as a legend, which describes the LEVELID
					attributes of the	coverage.  For example, a shoreline segment assigned a LEVELID=3
					has, in the recent past, retreated between 2-4 ft annually, which is	considered a “low” rate
					of erosion.  (Note:  The rates table is only	viewable in Arc, not in Windows.) 
					
Table 1: Rates table (ratestable)
| Rowid | LEVELID | EROSION (Ft/Yr) | EROSION LEVEL | 
| 4 | 0 | -0.01 to 0.01 | No Change | 
| 2 | 1 | >0.01 | Accretion | 
| 1 | 2 | -0.01 to –2.00 | Slight | 
| 5 | 3 | -2.00 to –4.00 | Low | 
| 6 | 4 | -4.00 to –8.00 | Moderate | 
| 8 | 5 | < -8.00 | High | 
| 3 | 6 | Protected Area | Protected | 
| 7 | 7 | Unknown | Unknown | 
| 9 | 8 | No Data | No Data | 
6	Distribution Information
					6.1	Distributor
					10	Contact Information
					10.2	Contact Organization Primary
					10.2.1	Contact Organization: Maryland Geological Survey 
					10.4	Contact Address
					10.4.1	Address Type: mailing and physical address 
					10.4.2	Address: 2300 St. Paul Street 
					10.4.3	City: Baltimore 
					10.4.4	State or Province: Maryland 
					10.4.5	Postal Code: 21218-5210 
					10.4.6	Country: USA 
					10.5	Contact Voice Telephone: (410) 554-5500 
					10.7	Contact Facsimilie Telephone: (410) 554-5502 
					10.9	Hours of Service: 8:30 a.m. -4:30 p.m. EST 
					6.2	Resource Description: CD-ROM - CoErosionRates 
					6.3	Distribution Liability: None 
					6.4	Standard Order Process
					6.4.1	Non-digital Form: Along with historical shoreline vectors, the recent
					shoreline vectors are being displayed over 1988-1995 orthophotoquads and printed as
					a	paper map series, Shoreline Changes.  A Shoreline Changes map is available
					for most of the quadrangles	listed in Appendix 2.  Each map is $7.50, plus postage
					and shipping.  To order copies, contact the Publication Sales office at the Maryland
					Geological	Survey (Telephone: (410) 554-5505). 
					6.4.2	Digital Form
					6.4.2.1	Digital Transfer Information
					6.4.2.1.1	Format Name: ESRI coverage 
					6.4.2.1.2	Format Version Number: ESRI ArcGIS version 8.1 or later 
					6.4.2.1.6	File Decompression Technique: No compression applied 
					6.4.2.1.7	Transfer Size: Less than 4 Mb/county; see Appendix 3 - File size. 
					6.4.2.2	Digital Transfer Option
					6.4.2.2.2	Offline Option
					6.4.2.2.2.1	Offline Media: CD-ROM 
					6.4.3	Fees: Contact the Maryland Geological Survey (Section 6.1) for current
					fees.
					
7	Metadata Reference Information
					7.1	Metadata Date: 20030714 
					7.4	Metadata Contact
					10	Contact Information
					10.1	Contact Person Primary
					10.1.1	Contact Person: Lamere Hennessee 
					10.1.2	Contact Organization: Maryland Geological Survey 
					10.4	Contact Address
					10.4.1	Address Type: mailing and physical address 
					10.4.2	Address: 2300 St. Paul Street 
					10.4.3	City: Baltimore 
					10.4.4	State or Province: Maryland 
					10.4.5	Postal Code: 21218-5210 
					10.4.6	Country: USA 
					10.5	Contact Voice Telephone: (410) 554-5519 
					10.7	Contact Facsimile Telephone: (410) 554-5502 
					10.8	Contact Electronic Mail Address: lhennessee@dnr.state.md.us 
					10.9	Hours of Service: 9:00 a.m. -5:00 p.m. EST 
					7.5	Metadata Standard Name: FGDC Content Standards for Digital Geospatial	Metadata 
					7.6	Metadata Standard Version: FGDC-STD-001-1998 (June 1998)
					
APPENDIX 1
Bounding Coordinates of Maryland’s Coastal Counties and Baltimore City
| County | Bounding	coordinates | |||
| West ° | East ° | North ° | South ° | |
| Anne Arundel | - 76.8413 | -76.3486 | 39.2358 | 38.7169 | 
| Baltimore City | -76.7122 | -76.5294 | 39.3719 | 39.1977 | 
| Baltimore County | -76.8977 | -76.2663 | 39.7350 | 39.1544 | 
| Calvert | -76.7041 | -76.3605 | 38.7675 | 38.3058 | 
| Caroline | -76.0163 | -75.6983 | 39.1438 | 38.6483 | 
| Cecil | -76.2380 | -75.7522 | 39.7244 | 39.3597 | 
| Charles | -77.3422 | -76.6619 | 38.7063 | 38.1755 | 
| Dorchester | -76.4430 | -75.6997 | 38.7022 | 38.0113 | 
| Harford | -76.5730 | -76.0288 | 39.7322 | 39.2594 | 
| Kent | -76.3522 | -75.7544 | 39.3880 | 38.9925 | 
| Prince Georges | -77.0905 | -76.6691 | 39.1311 | 38.5327 | 
| Queen Annes | -76.4238 | -75.7261 | 39.2683 | 38.7872 | 
| Somerset | -76.1894 | -75.5216 | 38.3119 | 37.8838 | 
| St. Marys | -76.8883 | -76.1852 | 38.5108 | 37.8713 | 
| Talbot | -76.4627 | -75.8908 | 38.9491 | 38.5736 | 
| Wicomico | -75.9569 | -75.3077 | 38.5716 | 38.2008 | 
| Worcester | -75.6633 | -75.0450 | 38.4555 | 37.9938 | 
					 APPENDIX	2 
					Shoreline Dates, by Quadrangle
| Quadrangle | Quadrants | Date	of photography | 
| Aberdeen | SE | 19940408 | 
| Alexandria | NE, SE | 19930407 | 
| Annapolis | NE, NW, SW | 19940408 | 
| Assawoman Bay | NE, NW, SE, SW | 19890412 | 
| Baltimore East | SE | 19940408 | 
| SW | 19940404 | |
| Baltimore West | SE | 19940404 | 
| Barren Island1 | NE2 | 19940408 | 
| SW | 19930408? | |
| Benedict | NE, NW, SE, SW | 19930408 | 
| Berlin | NE, SE, SW | 19890412 | 
| Betterton | NE, NW, SE, SW | 19950325 | 
| Blackwater River | NE, NW, SE, SW | 19950325 | 
| Bloodsworth Island | NE, NW, SE, SW | 19880417 | 
| Boxiron | NE, NW, SE, SW | 19890412 | 
| Bristol | NE, SE | 19940404 | 
| NW, SW | 19930408 | |
| Broomes Island | NE, NW, SE, SW | 19930408 | 
| Cambridge | NE, NW, SE, SW | 19950325 | 
| Cecilton | NE, NW, SE, SW | 19950325 | 
| Centreville | NE, NW, SE, SW | 19920406 | 
| Charlotte Hall | SW | 19930408 | 
| Chestertown | NE, NW, SE, SW | 19920406 | 
| Chicamacomico River | NE, NW, SE, SW | 19950325 | 
| Church Creek | NE, NW, SE, SW | 19940408 | 
| Church Hill | NE, NW, SW | 19920406 | 
| Claiborne | NE, NW | 19920406 | 
| SE, SW | 19940408 | |
| Colonial Beach North | NE, NW, SE | 19930408 | 
| Cove Point | NW, SE, SW | 19930408 | 
| Crisfield | NE, NW, SW | 19880417 | 
| Curtis Bay | NE, SE | 19940408 | 
| NW, SW | 19940404 | |
| Deal Island2 | NE, NW, SE, SW | 19880417 | 
| Deale | NE, SE | 19940408 | 
| SW | 19940404 | |
| Denton | NE, NW, SW | 19950325 | 
| Dividing Creek | SE | 19890414 | 
| Earleville | NE, NW, SE, SW | 19950325 | 
| East New Market | NW, SE, SW | 19950325 | 
| Easton | NW, SE, SW | 19950325 | 
| Eden | NE | 19890417 | 
| NW, SW | 19880417 | |
| Edgewood | NE, SE, SW | 19940408 | 
| Elkton | NW, SE, SW | 19950325 | 
| Ewell | NE | 19880417 | 
| Federalsburg | NE, SE, SW | 19950325 | 
| Fowling Creek | NE, NW, SE, SW | 19950325 | 
| Galena | NE, NW, SW | 19950325 | 
| SE | 19920406 | |
| Gibson Island | NE, NW, SE, SW | 19940408 | 
| Girdletree | NW | 19880330 | 
| NE, SE | 19890412 | |
| Golden Hill | NE, NW, SE, SW | 19940408 | 
| Great Fox Island | NE, NW, SE | 19880417 | 
| Gunpowder Neck | NE, NW, SE, SW | 19940408 | 
| Hallwood | NW | 19890414 | 
| Hanesville | NE, NW, SE, SW | 19940408 | 
| Havre de Grace | NE, NW, SE, SW | 19950325 | 
| Hebron | NW | 19890417 | 
| Hobbs | NW, SW | 19950325 | 
| Hollywood | NE, NW, SW | 19930408 | 
| Honga | NE, NW, SE, SW | 19940408 | 
| Horseshoe Point | NW | 19940408 | 
| Hudson | NE, NW, SE, SW | 19940408 | 
| Indian Head | NE, NW, SE, SW | 19930407 | 
| Kedges Straits | NE, SE | 19880417 | 
| NW | 19890414 | |
| Kent Island | NE, NW, SE, SW | 19920406 | 
| King George | NE, NW | 19930407 | 
| Kingston | NW, SW | 19880417 | 
| SE | 19890417 | |
| Langford Creek | NE, NW, SE, SW | 19920406 | 
| Leonardtown | NW, SE, SW | 19930408 | 
| Love Point | SE, SW | 19920406 | 
| Lower Marlboro | NE, NW, SE, SW | 19930408 | 
| Mardela Springs | NE, NW, SE, SW | 19880417 | 
| Marion | NE, NW, SE, SW | 19880417 | 
| Mathias Point | NE, NW, SE, SW | 19930407 | 
| Mechanicsville | NE, NW, SE | 19930408 | 
| Middle River | NE, NW, SE, SW | 19940408 | 
| Millington | NW | 19950325 | 
| SW | 19920406 | |
| Monie | NE, NW, SE, SW | 19880417 | 
| Mount Vernon | NE, NW, SW | 19930407 | 
| Nanjemoy | NE, SE, SW | 19930407 | 
| Nanticoke | NE, SE | 19880417 | 
| NW, SW | 19950325 | |
| North Beach | NE, NW, SE, SW | 19930408 | 
| North East | NE, NW, SE, SW | 19950325 | 
| Ocean City | NW, SW | 19890412 | 
| Oxford | NE, NW, SE, SW | 19940408 | 
| Perryman | NE, NW, SE, SW | 19940408 | 
| Piney Point | NE, NW, SE | 19930408 | 
| Pocomoke City | NE, NW, SW | 19890414 | 
| Point Lookout | NW, SW | 19930408 | 
| Point No Point | NW, SW | 19930408 | 
| Popes Creek | SE, SW | 19930408 | 
| Port Tobacco | NW, SE | 19930407 | 
| Preston | NE, NW, SE, SW | 19950325 | 
| Prince Frederick | NE, NW, SE | 19930408 | 
| Princess Anne | NW, SW | 19880417 | 
| SE | 19890417 | |
| Public Landing | NE, NW, SE | 19890412 | 
| Quantico | SE | 19930407 | 
| Queenstown | NE, NW, SE, SW | 19920406 | 
| Rhodesdale | NE, NW | 19950325 | 
| SE, SW | 19880417 | |
| Richland Point | NE | 19940408 | 
| Ridgely | SW | 19920406 | 
| Rock Hall | NE, NW, SE, SW | 19940408 | 
| Rock Point | NE, NW, SE, SW | 19930408 | 
| Round Bay | NE, SE | 19940408 | 
| NW, SW | 19940404 | |
| Salisbury | NW | 19890414 | 
| Saxis | NE | 19890417 | 
| NW | 19880417 | |
| Selbyville | NE, NW, SE, SW | 19890412 | 
| Sharptown | SW | 19890417 | 
| Snow Hill | NE, SE | 19890417 | 
| SW | 19880330 | |
| Solomons Island | NE, NW, SE, SW | 19930408 | 
| South River | NE, SE | 19940408 | 
| NW, SW | 19940404 | |
| Sparrows Point | NE, NW, SE, SW | 19940408 | 
| Spesutie | NE, NW, SE, SW | 19950325 | 
| St. Clements Island | NE, NW | 19930408 | 
| St. George Island | NE, NW | 19930408 | 
| St. Marys City | NE, NW, SE, SW | 19930408 | 
| St. Michaels | NE, NW | 19920406 | 
| SE, SW | 19940408 | |
| Stratford Hall | NE | 19930408 | 
| Sudlersville | NW | 19920406 | 
| Swan Point | NE, NW, SE | 19940408 | 
| Taylors Island | NE, NW, SE | 19940408 | 
| Terrapin Sand Point | NE, SE | 19880417 | 
| NW, SW | 19890420 | |
| Tilghman | NE, NW, SE, SW | 19940408 | 
| Tingles Island | NE, NW, SE, SW | 19890412 | 
| Trappe | NE, NW, SE, SW | 19950325 | 
| Wetipquin | NE, NW, SE, SW | 19880417 | 
| White Marsh | SE | 19940408 | 
| Whittington Point | NE, NW, SW | 19890412 | 
| Widewater | NE, SE | 19930407 | 
| Wingate | NE, NW, SE, SW | 19950325 | 
| Wye Mills | NW, SE, SW | 19920406 | 
1 The date of photography for Barren Island SW is unknown. Although Barren Island NE was flown on 4/8/1994, Solomons Island SE, which adjoins Barren Island SW, was flown on 4/8/1993. The latter date was assigned to Barren Island SW.
2 The production of accurately georeferenced DOQQs depends on sufficient ground control. In open water, ground control is necessarily lacking, because land areas, if they exist at all, are small and/or inaccessible. Two quarter quads in the data set, Deal Island NW and Barren Island NE, contain so much open water that they are not properly tied to the adjoining tiles, Nanticoke SW and Honga NW, respectively. Consequently, the corresponding linework (shoreline) is not properly georeferenced. The shorelines derived from those two DOQQs are included in the data set solely for the associated shoreline type attributes. Their positions are inaccurate.
APPENDIX 3
Constituent Quadrangles and Attributed Shoreline File Size, by County
| County | 7.5’ Quadrangles | File size | 
| Anne Arundel | Annapolis, Bristol, Curtis Bay, Deale, Gibson Island, Horseshoe Point, North Beach, Round Bay, South River, Sparrows Point | 1.32 MB | 
| Baltimore City | Baltimore East, Baltimore West, Curtis Bay | 140 KB | 
| Baltimore County | Baltimore East, Curtis Bay, Edgewood, Gunpowder Neck, Middle River, Sparrows Point, Swan Point | 578 KB | 
| Calvert | Benedict, Bristol, Broomes Island, Cove Point, Lower Marlboro, Mechanicsville, North Beach, Prince Frederick, Solomons Island | 812 KB | 
| Caroline | Preston, Trappe | 260 KB | 
| Cecil | Earleville, Elkton, Galena, Havre de Grace, Millington, Northeast, Spesutie | 334 KB | 
| Charles | Benedict, Charlotte Hall, Colonial Beach North, Indian Head, King George, Mathias Point, Mechanicsville, Mount Vernon, Nanjemoy, Popes Creek, Port Tobacco, Quantico, Rock Point, Widewater | 776 KB | 
| Dorchester | Barren Island, Bloodsworth Island, Cambridge, Church Creek, Cove Point, Deal Island, East New Market, Golden Hill, Honga, Hudson, Kedges Straits, Nanticoke, Oxford, Point No Point, Preston, Richland Point, Taylors Island, Tilghman, Wetipquin, Wingate | 3.19 MB | 
| Harford | Aberdeen, Edgewood, Gunpowder Neck, Hanesville, Havre de Grace, Perryman, Spesutie | 710 KB | 
| Kent | Betterton, Chestertown, Galena, Hanesville, Langford Creek, Millington, Rock Hall, Swan Point | 760 KB | 
| Prince Georges | Alexandria, Benedict, Bristol, Lower Marlboro, Mount Vernon | 428 KB | 
| Queen Annes | Chestertown, Claiborne, Galena, Kent Island, Langford Creek, Love Point, Millington, Queenstown, Ridgely, St. Michaels | 1.13 MB | 
| Somerset | Bloodsworth Island, Crisfield, Deal Island, Ewell, Great Fox Island, Kedges Straits, Kingston, Marion, Monie, Saxis, Terrapin Sand Point, Wetipquin | 3.72 MB | 
| St. Marys | Barren Island, Benedict, Broomes Island, Charlotte Hall, Hollywood, Leonardtown, Mechanicsville, Piney Point, Point Lookout, Point No Point, Rock Point, Solomons Island, St. Clements Island, St. George Island, St. Marys City, Stratford Hall | 2.80 MB | 
| Talbot | Cambridge, Claiborne, St. Michaels, Tilghman | 2.08 MB | 
| Wicomico | Deal Island, Monie, Nanticoke, Wetipquin | 1.03 MB | 
| Worcester | Assawoman Bay, Berlin, Boxiron, Girdletree, Ocean City, Public Landing, Selbyville, Tingles Island, Whittington Point | 1.62 MB | 
 
 
