Assessing relative coastal vulnerability in a macrotidal environment to the increased risk of storm surges due to climate change

Abstract

Historically, there has always been a close relationship between Atlantic Canadians and the ocean; however, under climate change this relationship is evolving. In collaboration with the Atlantic Climate Adaptation Solutions (ACASA) project, the overall purpose of this research was to develop a tool which determines the vulnerability of a macrotidal coastal environment, such as those found in the Bay of Fundy, to the increased risk of storm surges associated with climate change, based on several physical and anthropogenic parameters.

In order to achieve the goal of developing a vulnerability assessment tool, two main objectives were defined. First, a conceptual framework was designed which outlined the variables to be used in the analysis and to illustrate the relationship among them. The variables used in this analysis are: freeboard, observed erodibility, coastal slope, width of foreshore, the presence of anthropogenic or natural protection, the presence of vegetation and coastline exposure (fetch length, dominant wind direction, and significant wave height) and morphological resilience.

Second, the guidelines set out in the framework were used to develop a custom Python programming script, within a geographic information system (GIS), in order to calculate coastal vulnerability. The analysis was performed for four coastlines, backshore, upper foreshore, middle foreshore and lower foreshore. The results of the analysis, which highlight areas of concern in regards to the risk of storm surge, allow for coastal managers and other stake holders, to make informed decisions for adaptation solutions.