It’s Really Hot Out Here, So Let’s Go Plant Some Trees
After the intense heat experienced by many of us this summer you probably wouldn’t be surprised to learn that this past July was Salt Lake City’s warmest one yet and the heat wave is continuing with us as September begins.
But did you know that Salt Lake County’s summer days are abnormally hotter than those in nearby rural areas? Our culprit is referred to as the urban heat island.
What is the Urban Heat Island?
Urban heat islands occur as the built environment of a city attracts heat and prevents it from being released by covering up naturally absorbing sources. For example, grass absorbs heat but covering it with concrete for a sidewalk that attracts warmth will make the city hotter. Researchers have found that the cumulative effect of all these heat-attracting sources results in cities being up to 17 degrees hotter than surrounding areas! Research conducted by the University of Utah used temperature monitors throughout the valley to measure our urban heat index. This research discovered that our parks with grass and shade are two degrees cooler than nearby residential neighborhoods.
The benefits that shady parks and park strips provide in reducing the urban heat island are just one of the reasons that Salt Lake City places an emphasis on maintaining them. The important role tree cover plays in reducing heat is evident when looking at the images of Salt Lake City below. The map on the left shows the Urban Heat Island Effect by noting how much hotter it can be in that area. The darker the red the hotter it is. The map on the right shows the percentage of tree cover canopy in the entire neighborhood. The darker the green, the more canopy cover in the neighborhood. When comparing the two images it becomes evident that when there are more trees, the urban heat index is lower.
Additionally, the image below provides another useful visual to understand what the Urban Heat Island Effect looks like in Salt Lake City. The image, taken from satellite by NASA, shows 300 West to the Wasatch Foothills. The image, taken on a hot summer day, demonstrates the Urban Heat Island Effect in action. Orange, red, and yellow indicate hot areas and blue and green illustrate the cool areas. With this in mind, it becomes clear that areas with less vegetation are the hottest. For example, Liberty Park, which is near the bottom left-hand corner, is very blue on the map indicating that it’s cool.
How can you reduce heat and contribution to the urban heat island?Read more