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The city as a system . L/O: To be able to describe the city as a system. Describe the information being shown in table 11.11 Suggest reasons for the patterns show in table 11.11 Explain how traffic patterns in Beijing has increased air pollution from SO2 and O3
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The city as a system L/O: To be able to describe the city as a system
Describe the information being shown in table 11.11 • Suggest reasons for the patterns show in table 11.11 • Explain how traffic patterns in Beijing has increased air pollution from SO2 and O3 • Explain the impact of polluted water on people’s health
So what? • Urban sprawl e.g. urban expansion takes up 200, 000 ha of arable land in China each year
So what? • Overcrowding and housing – shortage of housing (especially in LICs).
So what? • Tax revenues are insufficient to provide urban services. E.g. waste collection, water supplies
So what? • Underemployment and unemployment e.g. in developing cities unemployment rates = 30-40%
The sustainable city Hong Kong is a sustainable city To what extent is this true? Water, food, energy
The Brundtland Commission 1987 • Sustainable development: ‘development that meets the needs of the present, without compromising the ability of future generations to meet their needs’
http://www.wsd.gov.hk • The supply of water from Dongjiang at Guangdong, is now the major single source of raw water supply for Hong Kong. • The annual Dongjiang water supply has been now almost 70 - 80 per cent of Hong Kong's total demand starting since the late nineties.
Use figure 11.202 • Give an example of each feature in the diagram that relates to Hong Kong
Define the terms OUTPUT and INPUT. Explain why the examples listed above are categorised as either input or output (eg. why is energy etc considered an input in the city?)
City systems can be either ‘closed’ or ‘open’. • What do you think these terms mean?
Investigate the ‘Rogers Sustainable City Model’ • It may be worth doing an image search to find the model. • Describe the differences between the 2 ‘models’, and explain why they can be considered sustainable or unsustainable (think back to INPUTS, OUTPUTS, OPEN and CLOSED).
Large cities are often considered to be unsustainable systems because they consume large amounts of resources and produce vast amounts of waste. • Compact cities minimise the amount of distance travelled, use less space, require less infrastructure (pipes cables roads…), are easier to provide a public transport network for, and reduce urban sprawl. • BUT, if the compact city covers too large an area, it becomes CONGESTED, OVERCROWDED, OVERPRICED and POLLUTED. It then becomes unsustainable.
What is SUSTAINABILITY? • Which system (linear or cyclical) is most likely to be more sustainable? Why? Evidence? … is a sustainable city the same as an eco-city? This is an open question. I’m keen to see what ideas you come up with.
Describe the differences between a sustainable city and an unsustainable city