This essay investigates the urban heat island (UHI) phenomenon in Guangzhou, the commercial and manufacturing hub of southern China. Research and original fieldwork was carried out by Fleur Wang, a sixth form student in the British School of Guangzhou. Fieldwork involved using two transects that measured the difference in air temperature between SW-NE and E-W profiles of the city. Land uses in the city were also studied using Landsat satellite imagery. Results showed air temperature increased with high density urban built-up areas and decreased with vegetation cover in rural areas. Intensity of UHIs found were significant and varied from 2°C to 3.3°C, even when the weather conditions for UHIs were not optimal. The existence of UHIs remains a relevant global issue as over 50% of the world’s population now live in urban areas and methods of mitigation must be found to minimise its negative social, economic, and environmental effects.
INTRODUCTION
The aim of my investigation is to study the Urban Heat Island (UHI) effect in Guangzhou, the third most populated city in China. My alternative hypothesis is:
“the ambient air temperature will be highest in the city centre and lowest in the rural areas.”
My project objectives are:
• To determine if there is an urban heat island in Guangzhou, and where it is located
• To study the factors influencing urban heat islands
• To carry out primary and secondary research to draw my conclusions
The Urban Heat Island effect
(Source: http://icecap.us/images/uploads/URBAN_HEAT_ISLAND.pdf )
The urban heat island effect is simply the higher temperature found over and around an urban area. Heat islands are created by the increased absorption of heat by the materials of the buildings and roads. This...
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... CIE GCE Textbook, "Urban Climates"
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Weng, Q. (2003) Fractal Analysis of Satellite-Detected Urban Heat Island Effect. Photogrammetric Engrineering & Remote Sensing, 555-566
It is now a well-documented scientific fact that both the 20th and 21st centuries have experienced a general trend in terms of global warming. Scientific research and evidence clearly indicate that the earth’s surface temperatures are gradually increasing. There have been a variety of theories pertaining to the fundamental causes of global warming. However, one of the outstanding beliefs is that human activities are distinctively responsible for global warming. Although this phenomenon is not experienced on all regions around the globe, the average temperatures on the globe have increased by 0.7°C since 1900 (Hansen et al., 2006).
...cy Statement: “Planned and Inadvertent Weather Modification,”. Bulletin of the American Meteorological Society, 73, 337.
In 1950, only 13% of China’s population lived in cities (Seto, n.d.). Post 30 years, one hundred-million people moved to large cities from rural areas in China. This migration was considered the largest migration in human history. To compare this migration to western cities, the example of Shenzhen is used. For a Western city to have a population of three million to increase to ten million, it takes about a hundred years. 30-year old city, Shenzhen on the other hand made this population increase in just a decade (qtd. Caughey and Dawn). Today, over 53.7% of its population lives in cities; by 2020 it is projected that a whole 60% of the population will live in cities (Xinhuanet, 2014).
Urban heat is a term used to describe an occurrence where built up areas are hotter than the rural areas they are in proximity to. As urban areas become more and more developed, changes occur in the landscape. Infrastructure replaces open land and vegetation. Surfaces where heat used to be absorbed are replaced by surfaces that are dry and don’t absorb heat. Changes like theses cause urban regions to become warmer than rural regions, this forms, in a sense, an “island” of hot temperatures in the landscape. The heat is created by energy from the daily activities of people in big cities. These activities include commuting (cars, buses, and trains), and recreational activities.
...ts and roofs absorb sun’s energy, thus heating up the surface of an urban city, intensifying the UHI. The Berkeley Heat Island Team concluded that lighter asphalts, or ‘cool pavements’, reflected as much as 30 to 50 percent of sun light, which is significantly higher than 5 percent of new asphalt, and 10 to 20 percent of aged asphalt, and ‘cool roofs’ decrease temperature inside and outside the building. Such ‘Cool technologies’ also seem applicable to Seoul, in renewal and development of infrastructure continues. Government schemes to reduce energy consumption, initiate plans to raise efficiency of special areas, limit cars driving, encourage riding bicycles, create urban forests and gardens, rooftop greenery, and more. There are also methods of planning routes for wind, Blue Way, by planning infrastructures, to let wind swiftly flow in to decrease the heat.
Ever wonder how urban design affects our daily lives and the way we build? Rural, urban, and suburb areas have many positives and negatives that impact us and determines how we accomplish our tasks and manage our time daily. Some of the areas might be difficult for people to live in or might be easy for others. The areas manage the money and time we spend in doing activities or accomplishing our needs such as transportation, education, health care, and more. Urban areas regulate the type of architecture and urban design that is being built around us with their features and the urban ecology.
The city lies at the corner of the North China Plains and is surrounded north to west to north by the Yanshan Mountains. The mountains act like a cage keeping some of the pollution trapped in the city. During the summer and winter months, the weather can go from searing to frigid, causing a spike in energy consumption. Over two thirds of China’s power is generated by burning coal. During the winter months, air pollution by coal soars while in the summer months, the humidity keeps the pollution trapped within the city. Because of it’s location, Beijing relies heavily on wind to control its pollution. However one of the three winds that blows into the city comes from heavily industrialized areas in the south such as Shaanxi and
Limitations faced within this investigation was the inability to ascertain proper figures or raw data of the real differences rooftop gardens make with regards to temperature regulation and reduction, and energy costs . Thus the evidence and conclusion are based more on social impacts and general impacts of rooftop gardens that have been recorded from all around the world.
Runoff from Paved Surfaces – there is a considerable amount of urban runoff which has been acting as a causal phenomenon for thermal pollution. Urban runoff is discharged to the surface waters from paved structures like roads and parking lots has the capability to make the water warmer when drained to them. Mostly during summer seasons, the pavements get really hot. This creates warm runoff that gets into the urban sewer systems and then finally drained into the water bodies.
Nowadays, more than half of the world population lives in cities. Urban populations consume 75% of the world 's natural resources and generate 75% of waste. Cities have become consumers of enormous amounts of natural resources and generating massive environmental
Providing solutions for the good city pose questions such as: good for whom? what is good? etc. These questions prompt that good and city are two words that form more questions than answers. In these nebula of questions urban design plays an important role because its nature is in the urban and therefore in the city. As Madanipour points out, urban design occupies a potentially strategic place in shaping the city of the future (Madanipour, 2006).
Urbanisation at the global level to the study area level. Occurrence of Sprawl in general and occurrence of sprawl in Nashik city have been also discussed briefly. Criterions for the selection of the study area, the role of the remote sensing and geographical Information system in the urban studies limitiaon of the study area, aims and objectives and the literature Survey. Literature survey part of this chapter deals with the concept of urban sprawl, pattern of urban sprawl, measuring of urban sprawl, methodology and approaches of urban sprawl, problems, Global and National trends in urban sprawl, urban planning, land use and land cover, spatial-temporal analysis, modelling of urban sprawl, Urban Sprawl And Strategies For Sustainable Urban Development review of modern techniques Methodology adopted for the study is also discussed in
In a world where over half of the human population calls a city their home, the need to restructure and revolutionize the way we design our urban environments has never been greater. Currently, the notion that these vast metropolises of metal, concrete, and sludge could one day be fully realized pillars of sustainability is certainly laughable. However, when these same cities are constantly growing and multiplying across the globe, all the while using a greater and greater chunk of our planet’s energy, this impossible task becomes a necessary focus. To strive towards the closed, continuous loop of “true” sustainability could greatly alter the image of the modern city. Any improvement over the current state of urban affairs could carry weight, and even if that goal is not entirely fulfilled, the gained benefits would be immense.
The hypothesis of the chapter ‘Suitability in cities’ was that this ‘challenge-scope’ is more on environmental sustainability than ‘emerging’ and ‘transitional’ megacities. Focused on higher level environmental problems that affect not only the city, but act on a global scale, are being confirmed by the challenges that were found in the selected literature. London does this with a strong emphasis on challenges causing and being caused by climate change. They are now facing the difficult task to change from the old techniques where they relied on for ages to a more sustainable techniques. Changes already occurred but these were mainly focused on improving existing methods. This can be seen by water use, waste and energy supply. Water use is reduced by improving old systems, waste is not dumped anymore but burned using heat for other purposes, and energy supply still relies on existing technologies that are improved to be more sustainable. To become sustainable major shifts in technologies are needed. They should rely more on the resources that are already in the city to reduce their impact on the environment. Water from precipitation should be used, energy should be supplied locally and waste should be recycled as much as possible. They should, as stated in chapter two, become more circular than linear. How they
...or temperature to remain at a comfortable 87 degrees, despite the temperature outside. Eastgate Centre saves about 3.5 million dollars every year due to the lack of central heat and air (Doan). This simple observation of what nature has already discovered for us has saved Zimbabwe millions of dollars. Imagine the quality of life humans could have if architects continued to apply biomimicry to their design process.