Q How can geohazard risk assessments impact safety?
A by Jen Holmstadt
Every year, geohazards (natural hazards like floods and landslides) threaten public safety and cost billions of dollars in damages. These hazards impact private property like homes and businesses as well as public infrastructure like storm sewers, trails systems, and public parks. In worst-case scenarios, human lives are lost.
Natural hazards often feature “cascading effects.” Cascading effects are defined as any event that precipitates another, exacerbating the consequences. For example, wildfires denude slopes of vegetation, often leading to landslides after the next significant rainfall. These cascading effects increase risks to human safety as well as the overall cost in damages of each event.
Increasingly, professionals responsible for managing infrastructure assets, from city administrators to pipeline integrity engineers, are seeking methods of limiting the effects of these hazards by incorporating geohazard risk assessments into their asset management programs. The overall intent of these programs is to allow asset managers to proactively manage threats from natural hazards rather than react to them after they’ve already occurred. In many cases, relatively smal
l actions taken in advance can prevent or mitigate the effects of natural hazards.
GEOHAZARD RISK ASSESSMENT PLANS INCORPORATE SEVERAL BASIC PRINCIPLES:
Identify the Type and Location of Natural Hazards Possible:
In many organizations, no single dataset incorporates the location and type of hazard that may impact asset integrity. Geographic Information Systems (GIS) provide a means of assembling this dataset. Geohazard modeling techniques, coupled with the institutional knowledge of senior staff familiar with the challenges in their systems, provides a powerful tool for assessing risk.
Define the Consequences of Natural Hazard Events:
Understanding the consequences of each natural hazard, including cascading effects, is an integral part of geohazard risk assessment. Consequence definitions should include threats to public safety, the environment, and infrastructure as well as take into consideration cascading effects. For example, a 500-year flood event may cause road washouts. It may also cause a slope containing a natural gas pipeline to fail, impacting the integrity of the pipe. Both hazards impact public safety and the consequence definitions for this natural hazard should account for both.
Consult with Emergency Management Professionals:
Professionals responsible for responding to natural disasters have invaluable insights and information regarding the consequences of natural hazards. For example, they will know whether a street is a key road for routing responders during an emergency. They also know how the public will likely respond during emergency situations. Incorporating this information into mitigation planning is a key step to prioritizing mitigation strategies.
Implement Mitigation Strategies:
The outcome of these steps should be a list of locations where preventative measures should be implemented to mitigate threats to public safety. For example, slopes prone to landslides after rain events may be engineered to decrease failure probability. In many cases, these hazards are less costly to alleviate before they occur.
Periodically Re-evaluate Your Plan:
The old saying “If you don’t like the weather, wait a minute and it’ll change” loosely applies to geohazard risk assessment as well. Natural hazards are the result of many different natural processes that change over time, especially in areas influenced by human activity. Geohazard risk assessments should be periodically re-evaluated to capture and incorporate these changes into your asset management program.
Jen Holmstadt is Director of Oil/Gas Services with WSB and Associates. She has spent 10 years as an environmental consultant, specializing in geohazard risk assessments, contaminated site remediation, and project management. Jen currently sits on the Midwest Energy Association Gas Operations Steering Committee and is the Co-Chair of the Midwest Energy Association Emerging Professionals Committee. She can be reached at firstname.lastname@example.org.
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