Increased temperatures in urban area is a growing problem. There are a few factors which contribute to UHI. The first is that buldings, pathways and hardscapes retain heat. Using chemically based materials, as opposed to environmentally friendly materials, causes this effect to become more pronounced over time. Also, air pollution and energy consumption are also directly related to increased UHI. The strategies that they develop need to take this into account.
UHI Study Results
Landscape and Urban Planning recently published highlights of a astudy conducted in Columbus, OH relating to spatial models (see full article here). Their research looked at the determinants of UHI, specifically how spatial relationships are effected by pollution levels. The study looked at one region withinin Columbus. They looked at how they could to reduce the UHI effect using new urban design and land-use guidelines.
There were several factors that planners needed to considered. How much solar radiation the area receives, and how much open space and vegetation are present are important. They also considered how rooftop spaces and the presence water affect air temperatures. Parking structures and vacant lots retain heat, as do higher pollution levels and a lack of vegetation in the area. This results in a higher UHI which has a negative effect on the environment.
Design and land-use policies are at the heart of green planning. UHI can be reduced by increasing requirements for open spaces and greenery. Vegetation in open spaces, green rooftops and a balance with landscape greenery in urban areas immediately begin to reduce UHI. Using materiels in open ares that absorb water naturally also provide a better balance. Water permeable materials composed of naturally occurring materials in landscape pathways is important. This can dramatically reduce UHI. Urban planners need to consider this when developing a green strategy.
We need to look at the effect our urban areas are having on the environment. Developing green strategies to reduce the UHI effect is imperative. By altering our actions, we can balance out the effects of increasing levels of urban growth on the environment.