Friday, February 26, 2010

The Sun will be shining and my Children will burn: The Urban Heat Island. (I)

I apologize for two things, firstly for the lack of posts; and for the slightly macabre title. But I suppose all of us in Singapore can relate to it - the weather has been especially cruel of late, with yesterday's (24/2/10) temperature hitting 35 DegC. February 2010 could be the driest February (and probably one of the warmest) on record - rainfall is only half of February 2009. *sweats and melts*

My slightly-psychic-and-very-tall Urban Climates professor set us a project on the Urban Heat Island; we installed temperature sensors around different parts of Singapore, so if any of you guys see such stuff perched on a lamp-post innocently, please do not touch them (or take them down for that matter):

Before going into the details and purpose of the project, perhaps I should explain what exactly is an Urban Heat Island. Simply put, temperatures in urban areas are notably higher than those of rural, non built-up areas. This effect is especially pronounced 2 to 3 hrs after sunset. The nature of the built-material such as concrete and asphalt traps more heat in the day, and the urban geometry of high-rise buildings prevents this heat from leaving the urban environment, especially during nighttime (figure 1). 

Figure 1: The red arrows represent the heat released by the city, the urban geometry traps the radiation, making the city warmer at night. (yes I am absurdly free now HAHAH to have the time to make this diagram)

Also, lesser vegetation in Urban areas result in lesser evaporative cooling and hence, higher urban temperatures. Human activities also contribute waste-heat (cars, industries etc), but are secondary contributors towards the heat island phenomenon. When an area, especially the downtown core of the city (i.e. most built up), reveals a distinctly higher temperature than the non built-up areas, an Urban Heat Island is formed. 

The effects of Urban Heat island... well, I think we are all pretty familiar with them: 
- More intense human discomfort due to higher temperature - especially in the tropical regions (we are right smack in the middle of it)
- Higher possibility of Heat Waves 
- Higher energy consumption with the increase use of air condition

Singapore, being nearly 100% urbanized, is very susceptible to the Urban Heat Island effect. In fact, temperatures in the past - before rapid urbanization in the late 1960s - was nearly 7 DegC cooler than it is now (I read this somewhere, but I can't find the source now, will do so and upload it!). Thus, the nature of our project is to observe and compare temperature trends of different built-up areas in Singapore. Sensors were installed in HDB estates, Industrial parks and (hopefully) Green Spaces such as Lim Chu Kang and/or Bukit Timah.

My friend Nicolette and I, being the adventurous-we-like-to-give-ourselves-trouble sort, decided to install our sensor (which we christened 'Hobo') at Sungei Kadut Industrial Estate. For those who have no idea where that is, it is the stretch of scary-looking heavy industries you see on your way from Yew Tee MRT station to Kranji MRT station. 

Here's Hobo looking right at home in this godforsaken place:

Spot Hobo in this picture:

And here is a sneaky unglam pictures of me taken by Nic as I struggle to attach Hobo to its new home.  The very nice cabbie uncle decided to give us a hand. Oh. you may also notice the chair I lugged from Jurong East all the way to Kranji, but that's besides the point: 

Perhaps, you may be wondering what's the whole point of this study. But heat is a critical issue, especially so for Singaporeans and our rising electricity costs (I hear my dad screaming at the background). By collecting data, studying them and gaining further insights to such temperature trends, we (or maybe the government) can then come up with some solutions to this problem. On the broader scale, this can very well relate to all the climate change talks that has been going around. I'm not saying Urban Heat Island contributes to climate change - NO it does not, it is a local phenomenon. But it certainly does add on to the temperature stress that cities like Singapore is already facing with rising global temperature. 

So, stay tuned for updates about Hobo's time at Kranji. We will be collecting and collating our data in 3 weeks time. So, till then (: Meanwhile, please avoid taking any sensors down if you happen to see them around!

Love, Serene!

Special thanks to Miss Nicolette Ng for doing the whole Kranji thing with me (its your idea HAHAHAHA); and Mr Joey Kang for correcting my grammar mistakes!

Disclaimer: Climatology is not my forte, I welcome any corrections and/or critiques!

1 comment:

  1. This is interesting stuff. I once did a related project advocating rooftop gardening as a solution for sustainable vegetation and one benefit we explored was the lowering of the roof temperature.

    It was significant that rooftop floor tiles can reach a whooping temperature of 51 degree celcius on a sunny day. Meaning to say that heat absorbed by a building can easily affect its temperature, air flow and etc. This problem is made worse in Singapore due to the urban landscape causing the urban heat phenomenon.

    I most certainly look forward to the result of your research.

    Hua Sheng