Rapid urbanization and climate change have increased the frequency, impact, and costs of flooding. The U.S. National Centers for Environmental Information estimates that the average cost of an individual flood event is $4.6 billion. But flooding is not limited to the United States. Increased intensity and frequency of precipitation events have affected communities across the globe, highlighting inadequate stormwater drainage systems and the expansion of impervious surfaces, which puts urban dwellers at a high risk of potential threats. The magnitude of flooding is expected to increase, and affected communities will continue to be socially, economically, and physically vulnerable. How can flood mitigation strategies help improve the resilience of these communities?

In a new study, “An Investigation of the Current Situation of Floodplain Mapping in British Columbia: A Fuzzy Rule-Based Approach,” researchers Manjot Kaur, Sana Saleem, Kh Md Nahiduzzaman, Kasun Hewage, and Rehan Sadiq assess the nature and status of preparations for floodplain maps. They propose a schematic perception–action–state–accessibility–usage (PASAU) framework to confirm the current state of floodplain mapping. Using the province of British Columbia, Canada, as a case study, the authors reviewed local governments’ and first nations’ flood risk, specifically asking if floodplain maps were available, when they were created, demographics of the community, historical flood occurrences, and more. Following the survey, key indicators were defined, and the authors ranked the communities on a low, medium, and high scale. They discovered a pressing need to create and update floodplain maps. Read about their framework, findings, and recommended next steps to enhance the disaster resilience capacity of the relevant geographical territories in the Journal of Urban Planning and Development at https://doi.org/10.1061/JUPDDM.UPENG-4364. The abstract is below.


The increased intensity of floods has become an emerging phenomenon in British Columbia, Canada. Flooding causes significant damage to properties and the built environment. The flood damage is magnified by the unthoughtful location choices for settlements and incoherent land use policies. This has severely restricted the capacity to build resilience to adapt to the unpredictable challenges of floods. Therefore, a thorough understanding of the current state of the floodplain maps that entail the spatial distribution of floods and the associated risks to the communities is paramount. Therefore, the British Columbia Real Estate Association (BCREA) attempted to identify pathways to increase awareness of the current state of the floodplain maps and prepare an updated inventory and its vitality to build resilient communities. The survey results suggested that 38.5% of the communities have created or updated their floodplain maps since 2015, and 62% of the maps meet the British Columbia Flood Hazard Area Land Use Management Guidelines. However, a survey conducted in 2020 suggested an increase in the response rate by 12.8%, which indicates a growing urgency to mitigate flood risks. Due to a lack of expertise and pertinent knowledge, 46% of the communities could not create or update the floodplain maps. In addition, the lack of provincial funding was identified as a key impediment to the floodplain mapping that was experienced by 37.5% of the communities. A schematic perception–action–state–accessibility–usage (PASAU) framework was proposed in this study to confirm the current state of floodplain mapping. The British Columbia, Canada, regions were ranked following a fuzzy rule-based approach to assess the nature and status of preparations for floodplain maps. The result suggests that the Northern Territories, Canada, lie at the low and others are at the medium scale. Communities that scored low were attributed to a lack of funding, in-house expertise, data, and planning endeavors. This study suggested actions for different tiers of the government to make the communities safer and more resilient.

Learn more about those actions in the ASCE Library: https://doi.org/10.1061/JUPDDM.UPENG-4364.