Integrating Social Dimensions into Flood Cost Forecasting

Many people potentially affected by flooding will undertake measures to either control flood levels or mitigate the damaging effects of the flood (e.g. use of berms, flood gates, sand bags). However, not everyone is in a position to prevent or mitigate damages incurred by a flood event. Thus, while flood-related costs are determined through economic assessments, there are social dimensions to property protection that will impact the actual damages incurred. To incorporate these additional dimensions, an index is developed to identify areas of increased social vulnerability in relation to pre- and post-flood warning preparation to mitigate property damage and facilitate evacuation. Education level, income, age, and familial dependencies are considered as contributors to potential social vulnerability of residents to respond to immediate pre-emergency flood preparation, and these are integrated with technical damage calculations to provide greater context for flood management planning. A case study application to the Credit River basin in southwestern Ontario is used to demonstrate the methodology. Analyses demonstrate that in this example application, the areas most prone to financial damages are also those where people are potentially more socially vulnerable, and indicate that total damages may be far greater in these areas than physical and monetary damages alone.