Accumulating Flood Risk

• A Model Study to Quantify Flood Damage Mitigation Measures under Dynamic Vulnerability

• Author / Creator

  Bryant, Seth

• Responding to rising disaster damages and shrinking budgets, Canadian cities are looking for ways to maximize protection from flood damages while minimizing costs. To inform such mitigation investments, quantitative decision-making tools have been used for decades to evaluate structural protection measures (e.g. levees), where estimating the current risk using a ‘static view’ (where vulnerability does not change through time) is thought to be adequate. However, no such tool exists to evaluate time-sensitive mitigation measures such as Flood Hazard Regulations (FHRs). Unlike structural protection measures, FHRs mitigate flood damage over time as flood-specific building rules guide new development towards less vulnerable buildings. Despite widespread application of FHRs in Canada since 1975, decision makers have no method to quantitatively evaluate FHRs or answer questions like: how much flood risk do FHRs mitigate?

  To address such questions, a dynamic view of flood risk is needed. This dynamic view conceptualizes the intersection of increasing flood hazard and heightened urban vulnerability as driving an accumulation of flood risk. Working towards such a dynamic view, this thesis develops the novel Stochastic Object-based Flood damage Dynamic Assessment model framework (SOFDA) and applies it to single-family homes in the Sunnyside/Hillhurst neighborhood of Calgary, Canada. SOFDA builds on the 2014 Rapid Flood Damage Assessment Model (developed by the Government of Alberta) to create a framework that includes: stochastic uncertainty; property level mitigation measures; and urban redevelopment. Using SOFDA to quantify dynamic flood risk in the study area, a simulation experiment is used to: 1) evaluate the shortcomings of the traditional static view of risk; and 2) explore the potential for optimizing Calgary’s current FHRs.

  Model results suggest that, for structural protections in redeveloping neighborhoods (like Sunnyside/Hillhurst), traditional static-methods underestimate the present value of flood risk mitigations. Further, a novel FHR that avoids onerous building restrictions was evaluated and shown to improve the risk mitigation of the current FHRs by 9.7%.
  While the transferability of this specific case study is unclear, the significance of vulnerability dynamics for flood risk assessments is obvious. Further, this study unlocks the quantification of FHRs and other time-sensitive mitigations for decision makers, allowing them to optimize from a wider range of flood defenses for their communities, including more tailored and effective FHRs. With this new tool, decision makers can move past a static view of risk focused on today’s communities — and towards more robust and resilient mitigations for the uncertain risks of tomorrow.

• Subjects / Keywords

  • Flood Risk

• Graduation date

  Spring 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-h2xs-8404

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.