Hurricanes, floods, drought, and other extreme weather events driven by climate change have led to concerns about the resilience of pipes, culverts, and other drainage infrastructure: How well can they withstand increasingly severe weather? A University of Minnesota Duluth (UMD) researcher has created an assessment tool to measure infrastructure resiliency and help engineers specify appropriate drainage systems for their projects.
“The effects of climate change and extreme weather events pose a certain level of risk to buried drainage structures,” says Michael Pluimer, an associate professor in UMD’s Department of Civil Engineering and principal investigator for the project. He also notes that the resiliency of a material has a direct impact on climate change itself: Replacing a structure repeatedly can lead to excessive energy use, which in turn contributes to greenhouse gas emissions.
Pluimer devised a way of calculating a “vulnerability rating” for different materials used for buried drainage infrastructure such as corrugated thermoplastic, corrugated metal, and reinforced concrete pipes. The method uses data gathered from the National Oceanic and Atmospheric Administration (NOAA) and a survey sent to state departments of transportation around the US.
The rating takes into account both the potential severity and likelihood of a given weather event causing damage. Floods, for example, are rated as highly damaging; 94 percent of survey respondents reported having replaced flood-damaged infrastructure in the past. Floods are also very likely to occur and are becoming more extreme in nature: NOAA has reported a steady increase in severe floods across the country since the 1980s.
The rating also includes information on the durability of the material. The survey showed, for example, that reinforced concrete pipes tend to experience joint separation, and corrugated metal pipes tend to experience excessive corrosion over time, which may lead to early replacement of these structures.
The vulnerability rating assigns each drainage structure a number from 1 to 100. Ratings from 0 to 33 indicate “low-risk—no changes needed to the design,” 34 to 66 indicates “medium risk—consider some mitigation strategies,” and 67 to 100 indicates “high risk—consider other alternatives or mitigation strategies.”
The rating tool can also be used for other natural disasters such as fires and earthquakes.
A paper summarizing the research—Holistic Approach to Evaluating the Sustainability and Resiliency of Buried Drainage Structures Relative to Climate Change—was published in the Transportation Research Record,Volume 2677, Issue 5, 2023.
—Sophia Koch, contributing writer
