This information supports coastal hazard mapping, planning tools like CHRIS, and decisions about how to adapt to future coastal risks.
Mapping Shore Types in PEI
PEI’s coastline includes wetlands, salt marshes, dunes, cliffs, bluffs, low plains, and armoured shores. Each shore type responds differently to storms, erosion, sea-level rise, and human activity. Together, they form a connected coastal system that influences how water, waves, and sediment move along the shore.
Example of shore type classification, in the Cavendish National Park area
The Province uses aerial photos, elevation data (LiDAR), earlier shoreline studies, machine learning, and expert review to map and classify these shore types. The resulting colour-coded map helps identify coastal features, track changes over time, and better understand how different parts of the coastline may respond to future conditions.
By mapping shore types and monitoring change, the Province can better understand coastal risks and support informed decisions that help communities adapt while maintaining healthy, resilient coastlines.
The Role of Salt Marshes
Found in sheltered bays and estuaries, they absorb wave energy, reduce flooding and erosion, improve water quality, store carbon, and provide wildlife habitat. Mapping from 2010 and 2020 helps show how these natural coastal buffers are changing. As sea levels rise, salt marshes need space to move inland, but development, roads, shoreline hardening, and erosion can limit this movement.
Illustration of a salt marsh drowning and migrating inland as a result of sea level rise
Measuring and Monitoring Coastal Change
The Province monitors coastal change by comparing mapped coastlines from different years. This work uses historical orthophotos, newer aerial imagery, satellite imagery, and GIS analysis to measure how the coastline has moved over time.
What is an orthophoto? An aerial photograph that has been corrected so it lines up accurately with maps.
How coastal change is measured:
Imagery Collection
Aerial imagery is collected by flying over PEI in a small aircraft and taking photographs. Satellite imagery or drone imagery may also be used, especially after major storms.
Delineating the Coastline
The collected imagery is stitched together to create a continuous view of PEI's coastline. The coastline is then traced, or delineated, using visible shoreline indicators. These indicators vary by shore type and may include the top of a bank, the edge of vegetation, a dune edge, or another visible coastal feature.
Determining Rates of Coastal Change
After the coastline is delineated, tools like the Digital Shoreline Analysis System, or DSAS, can be used to measure how much the coast has moved over time. Measurement lines, called transects, compare coastline positions from different years and help calculate rates of change.
If the coastline moves inland, it usually indicates erosion. If it moves seaward, it may indicate accretion, or sediment buildup. These rates help identify where PEI's coast is changing and support tools such as CHRIS and Coastal Hazard Assessments.
distance moved ÷ time
