Fake city shows heatwave weaknesses

Washington Post writers have constructed a hypothetical city to demonstrate the disastrous effects of extreme heat on infrastructure – building a cautionary tale in “Meltsville”.

The project draws international inspiration from true examples of built environments that weren’t designed to endure extreme temperatures. Meltsville, through its article and accompanying dynamic graphics, illustrates that much of the world’s infrastructure was designed for a past climate, not a newly emerging and changing one.

In the Post’s scenario, the fictitious metropolis is accustomed to mild summers, but recently a “monstrous heat dome” descended, revealing design failures triggered by extreme conditions.

Heat freezes transportation

The Post hypothesises that initially, much of the population would try to relocate to cooler climes. However, looking to examples from cities such as Phoenix and Dubai, smaller planes will struggle with take-off in extreme heat. Hot air is less dense than cool air, so it provides less lift. Heat is also bad for machinery: engines and other components work harder, so manufacturers advise limits on take-off temperatures.  

Additionally, runway surfaces in cooler places often use a more viscous coating that, while durable in cold weather, can soften and even liquify in extremely high temperatures. This applies to roads, too.

According to the Post, although most materials are designed to handle a range of temperatures, they don’t necessarily cope well with extremes. Concrete slabs can expand, buckle and crack, and asphalt can become too soft to support heavy vehicles. Old surfaces may become brittle and damaged, while other protective coats can melt or burn away.

Another roadway concern is that heat waves expand both asphalt and steel.

“If you already have a poorly rated bridge that needs to be replaced, all of those additional stresses are, quite frankly, a little bit terrifying to think of,” says Ladd Keith, assistant professor of planning and sustainable built environments at the University of Arizona.

Supply and demand at full power

Next, the Post looks at the sudden increased power demand within its hypothetical city, where the fictional Meltsville Nuclear Power Plant would struggle to keep up.

Mikhail Chester, a professor of civil, environmental and sustainable engineering at Arizona State University, told the Post that power is probably the only infrastructure in which both the supply and the demand are significantly affected by heat. Chester’s work focuses on heat and infrastructure preparedness.

“You’ve got to supply the amount of electricity that is being demanded for air conditioning effectively, and at the same time, the system is compromised in a number of ways,” he says.

Thermoelectric plants, which include coal, nuclear and some natural gas plants, are compromised the most. According to Chester, if the water entering the plant or outside temperature is warmer, the plant becomes less efficient.

“Basically you’re going to be generating less electricity from the same lump of coal at the end of the day.”

Specifically, nuclear plants need more water to cool the reactors when the water is warmer, and the temperature of discharged water also needs to be kept in line with environmental regulations. Both can hinder the plant’s output.

Even for solar panels, a fraction of efficiency can be lost in hot weather.

For the infrastructure that delivers the power, the Post says power lines can sag due to extra electricity demand generating more heat. Power companies will regulate how much power runs through lines if they are drooping dangerously close to trees or buildings. Transformers and substations also can also struggle.

“Stuff just breaks more when it’s hotter,” Chester told the Post. “And that’s for a million reasons. Electronics break more, circuits cut out more. Everything just breaks more frequently.”

The Post goes on to explore the building infrastructure of Meltsville, theorising that water pipes break more frequently in extreme weather, and that building materials designed for cooler, rainy weather would not hold up under heatwave conditions.

Nature feels the heat

For the fictional occupants of Meltsville, seeking out shade is a problem too, writes the Post. Drawing on examples from Madrid parks that close during high heat events, some of the city’s shadiest parks would need to be cordoned off to avoid heat-stressed limbs that might break, fall and hurt someone.

Highlighting an Australian example from the 2019 heatwave that killed almost one-third of the nation’s spectacled fruit bat population before misting systems were installed, Meltsville’s wildlife encounters the same issue.

In the fictional city, residents take to hosing down bats – and park equipment.

The Post points out that while they provided only one fictional weather challenge for Meltsville, the reality is often more dire: extreme heatwaves can be accompanied by drought, wildfires and later flood damage to barren land. Meltsville had just one weather crisis to handle, with no water shortage, no wildfires, no storms.

“There’s a concept in engineering called stationarity, the assumption that your assumptions don’t change,” Millar told the Post. “With climate change, those assumptions are changing.”

Image via Raphael Wild on Unsplash.