Be sustainable: To solve Urban Heat Island Problem

The rapid development of urbanization brings significant benefits to residents and government. But there are many problems occur with this process. Among these problems, the urban heat island is a serious one. An urban heat island (UHI) is a city or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities (Wikipedia). The main cause of the urban heat island effect is from the modification of land surfaces, which use materials that effectively store short-wave radiation. This a long term effect in the urban areas. And it will have huge negative impact on environment and human health. As the aim to be a sustainable city, this problem should be solved.

At the beginning, we should know the factors that cause UHI. There are four main factors that influence the UHI. Firstly, Man-made heat source is one of main factors. It includes industrial boiler, vehicle and other kinds of heaters. These machines consume a lot of energy and generate a large amount of heat into atmosphere. Second factor is the effect of moisture. Because there are many buildings in the urban areas, the wind speed will be low. Moreover, wind can take moisture, and the heat capacity of water is high. When wind speed is lower than 6 m/s, the UHI will occur. The rest factors are air pollution and decreasing green field.

When we know the factors which may cause UHI, we can focus on these fields to solve this problem and to build a sustainable urban city.

First of all, the most important method is to increase the green field. The research illustrates that the more green-field is, the lower intensity of UHI is. When the green field covers more than 50% of total urban areas, the UHI won’t happen. Second method is to reduce heat generation into atmosphere. This can be solved by using renewable energy or clean energy like solar or electric. In addition, to control the air-condition use rate is a useful way to reduce effect of UHI. Finally, it needs the government to design well. For example, there is no need to make all tall buildings in one area, it will easily cause UHI.

In conclusion, a sustainable city should meet the entire standards as it called. Because the urban heat island impact on environment and human health, we have to solve this problem as soon as possible. The residents and government should do their efforts to build a sustainable and make the city better.

Reference:

Newman, P.W.G. (1999) Sustainability and cities: Extending the metabolism model, Landscape
and Urban Planning, Vol.44, 219-226.