by Deniz Korman
Urban areas experience higher temperatures compared to rural areas, and it is likely that this will lead to health risks within urban communities due extreme heat in the future. However, we have the power to minimize this effect by improving the infrastructures of our cities. An effective way to lower urban temperatures is increasing vegetation and water surfaces, which also provides the added benefit of increasing urban biodiversity, and improving air quality. While this known to be a valid strategy, the magnitude of the climate impact that such an improvement will have when applied on a city scale is unknown. Žuvela-Aloise et al. (2016) have modeled the potential of improving green and blue infrastructure within Vienna, and identified the ways in which changes should be applied in order to counteract urban warming as effectively as possible.
They have constructed two models: A simple model that used temperature data to find a trend in overall temperature increases at various locations across the city, and a detailed model that took detailed climate and land-use data to get an understanding of how elevation, density of urban development, as well as air flow affected temperatures across the city. The authors have then used their models to simulate the impact that introducing or expanding green and blue surfaces will have on local temperatures. Their findings suggest that the most effective way to reduce heat load is to introduce green and blue spaces within the areas with highest building densities. Considering that this may be unfeasible, they have also suggested the introduction of green spaces on a wider scale, such as along highways, to be an effective cooling method. Overall, they have found that making small changes such as increasing green and blue spaces by 20%, and decreasing building and pavement density by 10% and 20% respectively would provide a substantial cooling effect, reducing the number of summer days (defined as days in which the maximum temperature is above 25) by at least 10 days.
Žuvela-Aloise, M., Koch, R., Buchholz, S., Früh, B., 2016. Modelling the potential of green and blue infrastructure to reduce urban heat load in the city of Vienna. Climatic Change 135, 425–438.
GSSS: “Žuvela-Aloise green and blue”
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