Open Collections

Strouth, Alexander Brian

University of British Columbia

A risk evaluation compares a risk with perceptions of tolerable risk, benefits of taking the risk, and available resources and options for managing the risk. It is part of a structured framework for guiding decisions. It can help answer questions like, is the community safe enough from landslides and, if not, how much should be invested to protect it? Since 2005, for residential developments in British Columbia, probability of death due to a landslide, which we call life-loss risk, has been compared with risk tolerance thresholds that are intended to differentiate risks that are too high to be accepted from those that are low enough to be lived with. Local governments have used these risk evaluations to request funding from provincial and federal governments for landslide protection. The risk assessments were intended to provide clear justification for the landslide mitigation investments. But, an analysis of case studies has shown that this intention has not been met. Instead, the resulting landslide mitigation designs have tended to be unaffordable, and the risk evaluations have failed to persuade funding authorities that proposed risk management solutions are a justifiable allocation of governments’ limited resources. Therefore, this research aims to review and improve the methods for quantitative life-loss risk evaluations used for landslide risk management in British Columbia. Its goal is to shape a process that leads to fair, efficient, and affordable landslide risk management solutions that can be adapted for implementation around the world. This research explores both sides of the risk evaluation comparison, including the risk estimate itself and the risk tolerance criteria. It provides a new method for improving the accuracy of life-loss risk estimates based on historical fatality data, and it explores the overlooked and misunderstood aspects of risk tolerance thresholds and conditions for tolerating risks. In conclusion, the research shows that a simple comparison of life-loss risk with a universally applied risk tolerance threshold is usually inadequate and inappropriate. Many other factors control decisions, like economic risks, available funding, and political priorities. It is now time to include these factors more explicitly in our landslide risk management decision process.

Text

2024-03-15

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/87585

Geological Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/