Unequal Vulnerability to Flood Hazards: “Ground Truthing” a Social Vulnerability Index of Five Municipalities in Metro Vancouver, Canada

Indexes that measure social vulnerability to hazards have gained acceptance as a research tool that can inform local policymaking. Many indexes, however, are created remotely by researchers without using the input of those working in local policy. If practitioners are involved in creating an index that they find accurate and useful, it is more likely they will incorporate the findings of the index in local policy decisions. This article describes the process of ground truthing a social vulnerability index with practitioners working in five municipalities in Metro Vancouver and how the index was then revised to reflect their input. This process involved presenting an index to focus groups of municipal practitioners for their feedback and conducting a survey of participants that was then used to assign weights to the variables in the index. The study found that practitioners were generally accepting of the research approach to quantifying social vulnerability by place, although they often had specific concerns regarding the methodology and offered suggestions to make the index more reflective of the local context. The process of revising the index illustrates that local practitioner input can be used to create a measure of social vulnerability to hazards that is meaningful to those working in the community.