As previously mentioned, the southwestern coast of British Columbia is particularly vulnerable to a catastrophic earthquake within the next 50 years which is predicted to seriously impact the livelihood of much of the population (OAGBC, 2014). Within this earthquake prone area lies the GVRD, whose risk to hazards is most significant due to high population densities and vital infrastructure (Clague & Bobrowsky, 2010). The BC Census Regional District and Municipality Population Estimates (2016) states the GVRD population, contained within 22 municipalities, to have breached 2.5 million. This constitutes approximately 54% of BC’s population, meaning over half of the province’s population is potentially subject to high earthquake hazard risk. Furthermore, due to its location between the Western Cordillera Mountains and the Salish Sea, this area is somewhat isolated from interior BC as there is potential for blockage of major transportation lines through mountain valleys from soil liquefaction and slope failure (Clague, 2002). The boundary limits of GVRD, outlined in Figure 1, define the scale of this earthquake risk analysis and model of optimal evacuation routes.
Figure 1: Proposed study area for evacuation routes in the GVRD. Data sources: Municipalities, Urban Centres (Metro Vancouver, 2015); British Columbia land area (BC Stats, 2011); US land area (United States Census Bureau, 2014).