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Recent (1988-1995) Maryland Shorelines with Erosion Rate Attributes

Entry ID: md_SLM

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Summary

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.

[Summary provided by the Maryland Geology Survey.]

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.

Related URL

Link: GET DATA

Description: Access data sets for the Recent (1988-1995) Maryland Shorelines with Erosion Rate Attributes.

Geographic Coverage

(Click for Interactive Map)

Spatial coordinates

N: 39.62

S: 37.88

E: -75.0

W: -77.37

Data Set Citation

Dataset Originator/Creator: Maryland Department of Natural Resources, Chesapeake Bay & Watershed Programs, Resource Assessment Service, Maryland Geological Survey (MGS)

Dataset Title: Recent (1988-1995) Maryland Shorelines with Erosion Rate Attributes

Dataset Release Date: 2003

Dataset Release Place: Baltimore, Maryland, USA

Dataset Publisher: Maryland Department of Natural Resources, Chesapeake Bay & Watershed Programs, Resource Assessment Service, Maryland Geological Survey (MGS)

Version: 1

Data Presentation Form: vector digital data

Other Citation Details: CD-ROM CoErosionRates

Online Resource: http://www.mgs.md.gov

Temporal Coverage

Start Date: 1988-04-17

Stop Date: 1995-03-25

Location Keywords

CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > DELAWARE

CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > DISTRICT OF COLUMBIA

CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > MARYLAND

CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > VIRGINIA

Science Keywords

OCEANS > COASTAL PROCESSES > BEACHES

OCEANS > COASTAL PROCESSES > EROSION

ISO Topic Category

INLAND WATERS

OCEANS

Platform

AIRCRAFT

Quality 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 ...

Access Constraints None

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.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.

Ancillary Keywords

vector

county

Data Set Progress

COMPLETE

Originating Center

Maryland Geological Survey

Data Center

Geological Survey, Maryland

Data Center URL: http://www.mgs.md.gov

Data Center Personnel
Name: BOB CONKWRIGHT Email: bconkwright at mgs.md.gov Contact Address: 2300 St. Paul Street City: Baltimore Province or State: MD Postal Code: 21218 Country: USA

Distribution

Distribution Media: Online

Fees: No fees

Personnel

LAMERE HENNESSEE

Role: TECHNICAL CONTACT

Phone: 410-554-5519

Fax: 410-554-5502

Email: lhennessee at mgs.dnr.md.gov

Contact Address:

2300 St. Paul Street

City: Baltimore

Province or State: MD

Postal Code: 21218

Country: USA

TYLER B. STEVENS

Role: DIF AUTHOR

Phone: (301) 614-6898

Fax: 301-614-5268

Email: Tyler.B.Stevens at nasa.gov

Contact Address:

NASA Goddard Space Flight Center

Global Change Master Directory

City: Greenbelt

Province or State: MD

Postal Code: 20771

Country: USA

Publications/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 ...

Creation and Review Dates

DIF Creation Date: 2011-12-27

Last DIF Revision Date: 2012-01-03

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