43
The Challenges of City
tries that supply construction, principally including forestry, mining and quarrying, power generation, and transportation. It is therefore clear that decisions about where and how to build are critical if the ecological and economic balance of our society is to be maintained. Construction is one the world’s larg-
est employers and the quality of the con- ditions in which many millions of people work is as important as the quality of the buildings which they create. The links between human health and the built en- vironment have been well documented, but the emerging science of medical geology also addresses the effects of contamination in sub-surface conditions upon food, water, fuels, and air quality.
XX CITY LIMITS
The majority of the world’s population lives in cities. In theory, this should afford the opportunity to house, employ, and care for the largest numbers of people in the most environmentally sustainable manner. In reality, many global cities have become vast energy and resource consuming entities, producing waste and pollution on an enormous scale. Due to a lack of foresight and a system driven
EXPANSION T
he environmental impact of the construction industry worldwide is without parallel. To this must be added the impact of the indus-
Both the political world and the construction industry face a complicated juggling act of expanding our cities to accommodate a rising global population, while also minimizing the environmental impact and improving the quality of people’s lives. An insight into how this problem is being tackled.
BY NIGEL GRIFFITHS
by disparate commercial interests, these cities have become ringed by sprawling suburbia, or too frequently, the grinding poverty of slum settlements. Building within and around exist-
ing cities, effectively creating mega- cities, makes best use of the existing administrative resources and the physi- cal infrastructure. However, the pres- ent systems have often become greatly over-stretched, and far-reaching efficien- cy measures for energy, water use, and drainage must be introduced if further expansion is to take place. How to expand the world’s cities, while at the same time, reducing their environmental impact and improving the quality of life for their inhabitants is the greatest challenge fac- ing our present generation of urban plan- ners and politicians. Most cities contain a plentiful stock of brownfield sites and the redevelopment of these carries the dual benefit of building where facilities and transportation networks already exist, while cleaning up industrial contamina- tion and thereby reducing that particular environmental hazard. Increasing occu- pation density is in most cases economi- cally desirable and can contribute to the successful regeneration of deprived in- ner city areas, although it is wise to guard against overcrowding as this can ad- versely affect quality of life. Lastly, to re- duce the transportation demands of city dwellers, it is essential that the broadest
possible range of facilities is provided locally, within distinct communities, and that a balance of residential and com- mercial development is planned and delivered. In any case, an efficient and affordable public transport system is the cornerstone of sustainable city living in the 21st century.
XX GOING UNDERGROUND
As pressure increases on land availabil- ity in cities, geologists are turning their attention to the possibilities of extend- ing downwards. The third dimension (i.e. the sub-surface) may provide an escape route for many activities in over- congested megacities for which there is no more space at the surface. Beijing has 30km of underground city at present, and there are plans to expand to 90km by 2020. As even taller buildings will demand deeper foundations and hence increase available underground space, the population in developed countries is expected to spend more of its time underground. In cities such as Seoul or New York, large parts of the population spend hours each day in spacious and light underground shopping malls and offices. Cheaper, safer, and faster under- ground excavation techniques will en- hance development of the underground space which might well become an im- portant direction in urban development
Local Action Moves the World •
www.icleiusa.org
PLANET EARTH \\ CITY EXPANSION
CLIPART (13); ISTOCKPHOTO (3); SHUTTERSTOCK (3); AAPO HAAPANEN; JÖRG MOLLOWITZ; JONATHAN MCINTOSH; DCOETZEE; JERRY FERGUSON; SANWUISUSP
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68