Understanding the Sensitivity of Canada's Marine Coasts to Changing Climate

In an initiative known as CanCoast, we have investigated the sensitivity of Canada’s marine coasts to changing climate at the national scale. Sensitivity is the degree to which an environment may be affected by changing... [ view full abstract ]

In an initiative known as CanCoast, we have investigated the sensitivity of Canada’s marine coasts to changing climate at the national scale. Sensitivity is the degree to which an environment may be affected by changing climate. It considers physical environments and processes, and is one part of vulnerability assessments which might also consider risks to infrastructure, ecosystem services, cultural values, resilience, and adaptive capacity. CanCoast utilises a shoreline derived from CanVec 9 and has 1.4 million coastal segments, each of which was assigned attributes for changes in environmental forcings (sea-level, wave height including sea ice) and for settings (coastal materials, ground ice content, tidal range, and backshore slope). These attributes were scored from one to five using expert knowledge. We consider three different indices from these scores. In the first, the product of the scores is divided by the number of variables, and the square root is taken. The second is an average of two sub-indices representing sensitivity to inundation and erosion, each derived from the square root of the sum of weighted scores. The third is the geometric mean of the scores. All three indices are scaled from one to five and show the sensitivity of Canada’s marine coasts in a relative sense; they show relative differences in sensitivity in different regions. We present these indices for the purpose of discussion on the scoring and weighting of the variables that are important to understanding the sensitivity of Canada’s marine coasts to changing climate.