WDBJ7 Investigates the Urban Heat Island Effect in Roanoke

ROANOKE, Va. (WDBJ) - As we experience heat waves here at home – research shows heat can affect communities unequally.

When driving from Southwest Roanoke to the Hope Center in Northwest Roanoke, Director Darlene Lewis says the temperature difference was noticeable.

“It would be one degree and then when I got to the center, I would look at the temperature in my car and it would be another degree,” said Lewis. “So, it would be like oh wow it’s even hotter over here than the other side of town.”

Virginia Tech Urban Affairs and Planning Assistant Professor Dr. Theo Lim says this is due to a phenomenon called the Urban Heat Island Effect.

“It’s that cities that because they have less greenery and more materials that hold a lot of heat infrastructure, hard surfaces, impervious surfaces, concrete – are measurably hotter than the surrounding rural areas,” explained Lim.

But within cities, there can be an Intra-Urban Heat Island Effect – meaning the temperature can be even higher.

“Areas that are cooler within the city are areas that have more tree canopy cover, less density and areas that are hotter have less vegetation, less tree canopy cover,” added Lim.

In 2020, Roanoke was one of 13 cities funded by the National Oceanic and Atmospheric Administration (NOAA) to map temperatures in the city.

The study found temperatures within the Star City can differ up to 15 degrees F. Areas such as Northwest Roanoke have some of the hottest temperatures in the city.

“When I look around what’s around us outside is just concrete,” explained Lewis.

Lim says we can look to history to understand how we got here. He says Urban Renewal played a role in developing the issue.

“Sure. So, two ways Urban Renewal happened between you know the 50s all the way through the 90s. And it was all about funding for large infrastructures,” explained Lim. “And we know what causes the Urban Heat Island effect is the removal of Vegetation and it’s replaced with these materials that hold a lot of heat.”

Urban Renewal-related projects include the 581 Interstate, the Civic Center, and the Coca-Cola plant.

“And that’s why Gainsboro itself is an Intra-Urban Heat Island. It has higher temperatures than other areas in the city,” said Lim.

Tightly-knit communities were scattered to make way for the development. Lim says this disrupted social connections.

“If you have people checking in on neighbors. If you have people reaching out spreading information about the dangers of a heat wave that community will be safer,” explained Lim.

This summer Lewis has seen more demand for bottles of water and a cooling station at the Hope Center.

“The people in Northwest we have needs here,” said Lewis.

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