What if, without living through the consequences, a city could experience how it likely would fare during a disaster? A well-designed scenario can do just that. Seeing risk problems become clear in a possible event can spur action before an actual event, which saves lives and prevents unnecessary suffering.
GeoHazards International is leading a study on the use of scenarios to inform risk mitigation ahead of earthquakes, landslides, and volcanic activity. Funded by the U.S. Agency for International Development (USAID)'s Bureau for Humanitarian Assistance, our research aims to advance the practice of developing and using disaster scenarios in community planning processes. Please join our first webinar in a two-part series to hear more. We will share findings on how past scenarios were designed and how they resulted in efforts to address risks ahead of disasters. We will be holding two sessions on April 27/28 to accommodate various global time zones.
What do we mean by “scenario”? We use the term to describe work that depicts the impacts on a community of a plausible future disaster. It begins with a science-based model of a hypothetical earthquake, volcanic eruption, or landsliding event(s) overlaid with data on local buildings, infrastructure, and land. Damage and losses are then estimated, along with likely consequences to people, to make the findings relevant for planning and mitigation.
An earthquake scenario that included thousands of triggered landslides for Aizawl, India, led the city to create landslide hazard maps, and implement and enforce site development regulations.
A scenario of an earthquake or landslide often depicts an “event” and likely consequences, which can help shape a dialogue about how to change the outcome. A volcanic eruption, in contrast, may happen over several weeks or months, and the range of what may happen is considerable. Mapping the impacts as eruption conditions potentially change can help communities anticipate difficult decisions about who and when to evacuate.
Scenarios can be powerful motivators. A scenario’s effectiveness depends on how well people understand and act on what they learn. Some have helped decision makers see the value of investing in proactive measures to protect their community.
For example, an earthquake scenario in a remote region of western Nepal revealed landslides could block the only access road for over a month, which influenced plans to develop helipads for aid delivery. A scenario in an urban area of Wellington, New Zealand (GNS Science Reports 2012-030, 2013-041, 2014-042) estimated extended outages of both power and water, leading to integrated multi-stakeholder planning. San Francisco’s 2010 scenario-based Community Action Plan for Seismic Safety (CAPSS) led to a 30-year implementation plan and strengthening of over 4,400 vulnerable soft story buildings to date, with more building types planned. In Los Angeles, the 2008 ShakeOut scenario was a key catalyst for the city’s 2014 Resilience by Design plan and the resulting strengthening of more than 8,600 vulnerable soft-story buildings to date, plus water and telecommunications systems. Other examples of action have included land use and development policy, building code enforcement, and safer practices.
A 1997 earthquake scenario for Kathmandu Valley, Nepal estimated widespread damage, and vulnerable schools became a priority. This scenario sparked local action for safer construction, including NSET-Nepal retrofitting hundreds of schools. The 2015 M7.8 earthquake demonstrated the value of those proactive measures–all retrofitted schools survived. Two surviving schools above have seismic-resistant features.
What was our process? As part of our study, the team interviewed over 150 decision-makers, risk managers, hazard scientists, planners, and engineers in Ecuador, New Zealand, Nepal, and the U.S. who shared practical insights. We researched numerous earthquake, volcano and landslide scenarios that have been used worldwide, advances in risk communication, modeling compounding hazards, and six other topic areas that could advance scenario practice. We also conducted a companion study of earthquake scenario effectiveness in California, funded by the US Geological Survey.
The April webinar will focus on key findings from our research. The second webinar, scheduled for autumn 2023, will share recommendations on advancing scenario practice.
We hope you will join us on April 27/28. We plan to include a Q&A as part of the session to gather additional input and comments.
Looking forward to sharing our results,
Janise Rodgers on behalf of the Next Generation Scenarios Project Team
Bhutan · Dominican Republic · Haiti · India · Nepal · U.S.A.