Maryland Shoreline Erosion Rates From 1841-1995 Transects

Maryland coastal and estuarine shorelines are analyzed for rates of erosion and accretion using transect data. The dataset contains calculated change rates derived from shoreline vectors dating from 1841 to 1995, produced by the Maryland Geological Survey and U.S. Geological Survey using the Digital Shoreline Analysis System (DSAS). Updates began in 2015 to incorporate newer shoreline data for specific counties.

Use Cases

• Model shoreline retreat by analyzing transect-specific rates of change calculated between historical shoreline pairs.
• Assess regional erosion patterns by comparing DSAS-calculated rates across different counties like Anne Arundel and Calvert.
• Validate coastal change models using the time-series of shoreline positions from 1841 to 1995.
• Prioritize conservation areas by identifying transects with the highest calculated accretion or erosion rates.

Strengths

• Historical shoreline data spans over 150 years from 1841 to 1995.
• Transects are generated at a consistent 20-meter interval along the baseline.
• Data incorporates shoreline vectors from multiple authoritative sources including NOAA NOS T-sheets.

Limitations

• Specific row count, column details, and sample size for transects are unknown.
• Core rate calculations are based on data up to 1995, with updates for only 5 counties as of the description.
• Potential spatial bias as the newest erosion rate values are currently available for only five specified counties.

Provenance

Source

Maryland Geological Survey (MGS) and U.S. Geological Survey (USGS).

Collection Method

Analysis using the Digital Shoreline Analysis System (DSAS) on digital shoreline vectors derived from historical maps, T-sheets, and orthophoto interpretations.

Time Range

1841-1995 for core shoreline data, with updates post-2015.

Freshness

Update process began in 2015; last platform update recorded as 2026-04-05.

Geography

Coastal and estuarine shorelines of Maryland, specifically including Anne Arundel, Baltimore, Calvert, Harford, and Prince George's counties.