Assessing the suitability of living shoreline techniques for coastal erosion in Prince Edward Island, Canada

Abstract

Coastal erosion rates on Prince Edward Island (PEI) are increasing due to climate change. Wave action continuously works on the unconsolidated till and sandstone banks, eroding and receding coastlines, while nourishing beaches and estuaries. This causes intensified risk to properties, infrastructure, and humans. Hard engineered structures are common, short-term, solutions to coastal erosion. These structures disrupt the natural land-water interaction as wave energy is deflected at the structure and dispersed to adjacent areas, increasing erosion. Living shorelines are used as alternatives to hard structures by incorporating natural materials, such as vegetation, to provide coastal protection. Living shorelines are long-term methods for coastal erosion. These adaptations act as wave energy barriers and sediment traps, slowing erosion rates. Certain characteristics and baseline conditions such as vegetation, geology, geomorphology, sediment, and differing exposure types are required for living shoreline techniques to reap their intended benefits. Tools to assess site suitability for living shorelines, available online or through documents, are critiqued. The critique is based on how well the tool characterizes PEI, signifying how useful it would be if used as an assessment resource for the suitability of living shorelines. A multicriteria evaluation was conducted in ArcGIS Pro to identify segments of the shoreline that were suitable, moderately suitable, and unsuitable for implementing living shorelines. This model was tested using 31 field sites surveyed between July-August 2021. With this information, governments and coastal property owners will be able to determine whether or not their property would benefit from installation of living shorelines.