Driving Tri-Cities snowstorm scenes
Spring may be just around the corner, but according to the National Weather Service this year’s February snowfall in the Tri-Cities was the most on record since 1916.
Meanwhile, Chicago is still shivering from the polar vortex that caused temperatures to plunge to minus 23 degrees, the lowest in more than three decades.
As we were bundling up and doing our best to keep the snow and cold at bay, researchers at the Department of Energy’s Pacific Northwest National Laboratory continued their efforts to understand changes in the frequency and intensity of such extreme weather events.
Their research also seeks to identify the potential impacts of extreme weather on our dams, buildings and roads — and to increase the resilience of future infrastructure.
Public safety and national security
PNNL researchers take an interdisciplinary approach to these challenges.
Collectively, they apply their expertise in fundamental earth sciences, integrated modeling, risk assessment and engineering design practices to help protect public safety and national security.
For example, the team is exploring ways to better account for changes in the frequency and intensity of extreme weather events — like our record snowfall — over the infrastructure’s expected lifespan.
While conventional designs are based on historical, average weather conditions, the new research offers a clearer picture of potential vulnerabilities over time and offers robust, actionable guidance to those designing or remodeling infrastructure.
Several years ago, PNNL researchers developed a climate vulnerability assessment framework the Department of Defense uses to help manage its infrastructure and prioritize retrofits and new construction.
Weather impacts on energy, water systems
Looking at regional climate models, researchers analyzed storm surges, fire risk and changes in sea level. They modeled the impacts of hurricanes, including related effects on the region’s energy and water systems.
As a result, scientists identified how anticipated changes in weather or climate could impact infrastructure, equipment and training exercises.
PNNL researchers are now taking this approach a step further. Their new scientific insights are being incorporated into the engineering codes used to predict water availability, forecast floods and design infrastructure.
In this project, researchers set out to improve the accuracy of mathematical functions called Intensity-Duration-Frequency curves. These IDF curves are used to develop design standards for infrastructure to withstand storms of a given intensity, duration and frequency of occurrence.
Conventional IDF curves account only for actual rainfall — not excess runoff caused by unseasonably warm temperatures or heavy rains that melt snowpack more quickly or earlier than usual.
Capturing these rain-on-snow events is especially important in the Pacific Northwest, where excess runoff can overburden roads, bridges and culverts causing dangerous and costly landslides and flooding.
In 2007, extreme snowmelt events in Washington caused an estimated $900 million in economic damages and submerged a portion of Interstate 5 between Seattle and Portland for days.
With support from a joint program of the DoD, DOE and Environmental Protection Agency, PNNL scientists and engineers studied data from 376 snowpack telemetry stations across the western United States.
They combined this data with climate and hydrological models to improve IDF curves and enable engineering studies that could reduce the risk for infrastructure failure by 25 percent or more while also avoiding costly over-design.
While civil engineers and atmospheric scientists don’t typically work side by side elsewhere, it is commonplace at PNNL for those in the basic sciences and engineering disciplines to partner to address national challenges.
This is just one more example of the power of interdisciplinary teaming. We all can rest easier knowing that they are working hard to improve the resiliency of the infrastructure that underpins our economy and national security.