As Earth warms due to climate change, people living near the coast face a higher risk of hurricanes and are more likely to experience heat waves.
Harris County, Texas, is an example of a place where the risk of this compound hazard could occur in the future. The risk of a blackout-heat wave lasting more than five days would increase by the end of the century. The good news is that burying just 5% of power lines would almost halving the number of people affected.
When air conditioning isn't working, heat waves can become even more dangerous. The risk of extreme heat usually passes before the peak of the Atlantic Hurricane season. As global temperatures rise, heat waves are expected to occur more often and hurricanes are likely to become more common and more severe.
The power distribution network was destroyed by Hurricane Laura in 2020 and Hurricane Ida in 2021. The risk for this compound hazard has been increasing.
Lin and her coauthors looked at the risks associated with the compound hazard in a new study published in Nature Communications. Projections of hurricanes and heat waves in the future were combined with estimates of how long it would take to restore power after a storm.
Harris is the home of Houston, and it has the highest population density of any city on the Gulf Coast. 10% of Houston's residents lost power as a result of Hurricanes Harvey and Eisenhower.
By the end of the century, the percentage of Harris residents expected to experience at least one heat wave longer than five days would increase from 0.8% to 18.2%. The rural areas of the county will likely suffer more than other parts of the county.
Improvements to the power grid could reduce the impact of a heat wave. The percentage of people without power would be reduced from 18.2% to 11.3% if 5% of wires were buried near the distribution network's roots.
Lin said that the practice is randomly burying lines. We can reduce the risk by burying lines more strategically.
City planners can use this type of analysis to understand where residents are most at risk of a heat wave and to make improvements to their power distribution system.
An assistant professor in the Department of Civil and Environmental Engineering at the University of Illinois was not involved in the research. The paper connects the extremes with real world impacts.
Climate modelers, engineers and city planners need to work together to mitigate the risks faced by almost 30% of the US population who live in coastal counties. He said that they experience some extremes almost every year. Climate-informed infrastructure design is needed for people to realize it is not just infrastructure design.
Lin's group is trying to scale up the analysis of the compound hazard at the county level. They are looking for ways to reduce the computational demands of the analysis.
The new work shows the need to think about how climate change may affect the intersection of different dangers.
Lin said that climate can drive multiple hazards with compound effects that we don't understand. It's an important direction for the research community and for decision-making to consider this kind of compounding.More information: Kairui Feng et al, Tropical cyclone-blackout-heatwave compound hazard resilience in a changing climate, Nature Communications (2022). DOI: 10.1038/s41467-022-32018-4 Journal information: Nature Communications