Urban Heat Islands

What is the Urban Heat Island effect?

The urban heat island effect is a direct cause of over urbanisation. As cities and urban areas develop, changes in the city’s scape changes the surrounding environment including the temperatures in neighbouring areas.

Trees and vegetation disappear, moist and permeable land disappears, to be replaced by concrete. The concrete used for building traps heat causing urban heat islands (UHI).

How are Urban Heat Islands formed?

Urban heat islands (UHI) occur on the surface and in the atmosphere. They are formed because of the extra heat released from all the vehicles, machineries and industries located in big metropolitan cities.

Wherever there are lots of people and lots of activities going on, there are chances of formation of a UHI. ‘Waste heat’ also contributes to the formation of a UHI. People and the things they work with, such as cars and factories, are continuously burning off energy. Whether you are driving, or just living day – to – day lives, using everyday appliances, you are releasing energy into the environment in the form of heat. All these appliances and equipments release heat as a by-product, contributing to waste heat accumulating in the environment.

What are the harmful effects of UHIs?

• Urban heat islands have pretty bad air and water quality as compared to their neighbouring rural areas. One of the reasons is that more pollutants and wastes from vehicles, industries, and people, is being dumped into the air and water. UHIs are also a major contributor to global warming or increase in the temperature of the Earth’s surface.
• What do you do when it is really hot outside in the summer months? You run straight to your air-conditioned rooms. Right? Now, switching on the air – conditioners release even more heat energy into the environment, making the environment hotter than before. So, every activity of ours actually leads to the formation or aggravation of the UHIs.
• UHIs are also related to heat-induced ailments like heat strokes, heat exhaustion, heat syncope, and heat cramps and many other cardiovascular discomfort fatalities.

How to reduce the effects of the Urban Heat Islands?

• We can do several things around our homes to reduce urban heat island effects like :
• Plant trees and leave areas around our living spaces without construction. Tree plantation drives, using green roofs with plants on top of the roofs may help in reducing the effects of UHIs. Plants absorb carbon dioxide, a leading pollutant and also provide shade, helping to reduce the heat of the surrounding areas.
• Using energy efficient appliances and conserving electricity to reduce the overall load on energy production.
• Using our vehicles intelligently and also using other modes of transportation which are more environment friendly.
• Using lighter-coloured paint on buildings may also help. All of you know that the light colours reflect more sunlight and absorb less heat, keeping building interiors cooler.

3 Interesting facts about the Urban Heat Islands

1. These are some famous projects or buildings that either use the green roof or have adapted architecture to combat urban heat island effects.
2. Tao Zhu Yin Yuan, Taipei City, Taiwan, is a double helix eco tower under construction, designed by architects, Vincent Callebaut Architectures
3. A team of local residents and architects in St Pauli, Hamburg are transforming a 1940s bunker into green roof project in an attempt to rebuild urban spaces.