Debate: Compact cities are more sustainable than dispersed cities.

QUESTION : Contemporary debate shows that compact cities are more sustainable than dispersed cities .Critically evaluate this statement with the aid of practical examples. (50)

Modern cities are being faced with different problems. These problems include over use of natural resources, pollution, overcrowding, pollution, traffic congestion and urban sprawl among others. These problems have necessitated the development of different forms of urban development to help curb or do away with these problems. The main thrust of this essay is to evaluate the statement that compact cities are more sustainable as compared to dispersed cities with the aid of practical examples.

The term compact city was first coined in 1973 by George Dantzig and Thomas L. Saaty, two mathematicians whose utopian vision was largely driven by a desire to see more efficient use of resources (Jenks et al 1996).According to the two ,four conditions were necessary to enable the diversity essential for urban renewal that is mixed uses, small walkable blocks, mingling of building ages and types, and a sufficiently dense concentration of people. These four form the basic principles of compact cites. The compact city is an urban planning and urban design concept, which promotes relatively high residential density with mixed land uses, it is based on an efficient public transport system and has an urban layout which according to its advocates encourages walking and cycling, low energy consumption and reduced pollution (Jacobs 2000).It can also be referred to as the city of short distance. Thus in simple terms a compact city is a high density city aimed at addressing the problem of urban sprawl. The idea of a compact city emphasizes that urban activities should be located closer together to ensure better access to services and facilities via public transport, walking, and cycling, and more efficient utility and infrastructure provision. The basic provision of the compact city is the local community or neighborhood.

A dispersed city is one with low population density one with not many people per square mile. Its opposite is a compact city (Gordon and Richardson 1997).Dispersed cites are a complete opposite of compact cities. Dispersed city is a city with low density where journeys are made by car, with large lots and homes, homogenous neighborhoods with different origin-destination patterns, associated with generalised car use, the presence of express ways and arterial roads and scattering of activities (Hamel 1993) Dispersed cities comply more to zoning, that is having same uses at the same place. Most of the buildings in a dispersed city are horizontal. According to Landry (2006) ,a sustainable city is a city that is taking an intelligent, long-term collaborative approach to tackling the economic, social and environmental challenges that arise when more and more people come together in dense, compact areas, stretching already scarce resources. A sustainable city, or eco-city is a city designed with consideration of environmental impact, inhabited by people dedicated to minimisation of required inputs of energy, water and food, and waste output of heat, air pollution, methane, and water pollution. A sustainable city can feed itself with minimal reliance on the surrounding countryside, and power itself with renewable sources of energy. The crux of this is to create the smallest possible ecological footprint, and to produce the lowest quantity of pollution possible, to efficiently use land; compost used materials, recycle it or convert waste-to-energy, and thus the city's overall contribution to climate change will be minimal, if such practices are adhered to.

Compact cities are more sustainable than dispersed cities. Compact cities encourage densification. Densification in this case refers to the siting of a lot of activities on a small piece of and as well as a larger number .In other words higher population density for example Paris in France which has a population density of 21 263 people per square kilometer. In a compact city most buildings are built going upwards that is most of the buildings are vertically oriented. This paves way for the location of different types of activities on the same piece of land. This in turn reduces mobility as almost all services will be concentrated in one place. This results in a compact city becoming more sustainable than a dispersed as it saves land to be used for other purposes like agriculture.

Another principle of compact cities is that of reducing the use of auto mobile cars through the concentration of activities on the same piece of land, this makes compact cites sustainable than dispersed cites which scatters land uses thus necessitating the use of automobile cars (Breheny 1995).By concentration of different activities or land uses on the same place, distance travelled by people is minimised. That is why compact cities are sometimes referred to as short distance cities. Thus if people travel short distances to get services that they want there will not be any need to use auto mobile cars as everything will be in close proximity to the user. Increase in the use of cars in cities results in pollution, thus reducing the use of auto mobile cars in cities will on the other hand reduce air pollution. Unlike in dispersed cites were cars are of a necessity as different land uses are located in different zones, this necessitates the use of cars which will result in massive air pollution. Hence one is justified to say compact cities like New York City are sustainable than dispersed cities, as they help curb the urban problem of pollution.

Compact cities are more sustainable than dispersed cities, this is so because they result in the creation of diverse, compact, and mixed neighborhoods making it sustainable. Everyday activities, such as housing, work, schools, shops, and other amenities, are all ideally within a nineteen minutes walking distance of each other(Jacobs 2000). The aim is to provide a pleasant, comfortable, interesting, and safe environment for pedestrians, and to provide alternatives to car use such as public, transit and cycling facilities. Through the provision of a pleasant and safe environment to the people a sense of belonging and ownership is created .This results in social inclusion as well as the creation of social capital, a thing which dispersed cities does not offer as everyone is busy doing their own things at an isolated location. Thus compact cities like those in Singapore offer social sustainability making them more sustainable than dispersed cities.

Compact cities are more sustainable than dispersed cities because they offer environmental advantages which a dispersed city does not offer. A compact city that has fewer roads but more landscaped public spaces, parks, gardens, trees and other landscaping provide vegetation that shades and cools streets, courtyards and buildings in summer(Carmona 2010) .He further says cities are generally one to twenty degrees Celsius warmer than their hinterland (dispersed city). The overall effect of rich urban landscaping is to reduce the heat 'bloom' of cities, measurably reducing the need for air-conditioning. For example in Melbourne ,Australia plants dampen noise levels and filter pollution, absorb carbon dioxide and produce oxygen further factors that reduce the need for air-conditioning to supply cooled fresh air to buildings in what would otherwise be hot and polluted urban areas. Urban landscape absorbs rain, reducing the discharge of urban rainfall and storm water. Landscape plays an important psychological role in the city and can sustain a wide diversity of urban wildlife. All this a dispersed city cannot offer because activities are widespread over a large area ,reducing land that could be used for landscaping .Hence the dispersed city suffers from high temperatures as well as floods as there is little or no vegetation to absorb excess discharge. Basing on the above one is then justified to say compact cities are sustainable than dispersed cities.

Furthermore a compact city is more sustainable than a dispersed city. This is so because compact urban form strengthens the self-containment, diversity and multifunctionality of the city (Rogers and Gumuchdjian 2000).A compact city provides its inhabitants with all the services they need. jobs are found easily as a lot of activities will be taking place in the city. The city is able to sustain itself without relying on other cities, thus self-containment. With dispersed cities the case is different this is so because there is no diversity in the city as a result of zoning. Relying n other cities that is what the dispersed city does. The multifunctionality nature of the compact city makes it more sustainable than the dispersed city.

Compact cites reduce pressure on land through increasing densities within the existing urban fabric, this move reduces the developmental pressure to build on the fringes, yet accommodating for the rising population (Bekele 2005).This makes compact cities more sustainable than disperse cities. This is because compact urban form will result in large portions of land being reserved for future uses as well as future development .In dispersed cities the case is different as all the land is taken up by urban infrastructure and buildings thus restricting future development.

Efficiency in the use of available resources makes a city sustainable. Compact cities lower infrastructure costs making them more sustainable than dispersed cities. Compact cities assists in the reduction of capital expenditure costs on urban infrastructure by efficiently making use of the existing infrastructure.

Compact cities are more sustainable than dispersed cities. Compact urban form is beneficial climate change. The claim is true foe Los Angeles. Compact cities use less fossil fuel, emit less greenhouse gases as well as conserving agricultural and water catchments. This in turn help reduce the effects of global warming and climate change thus making compact cities more sustainable.

However compact cities with time and age starts to display their demerits which makes them less sustainable than dispersed cities. Compact cities result in increased congestion for example in Harare it takes one more than an hour to get to Chitungwiza, this is as a result of congestion in the Harare Chitungwiza road. This is so because as densities increase, so do the total vehicle hours per square kilometer of the city. Urban consolidation can replace land that could have potentially been a road reducing the congestion of a car park. Thus dispersed cities are less congested as traffic can move freely through major arterials and freeways.

Increased densities in compact cities result in increased pollution for example in most cities of China. Noise pollution comes as a result of the settling of many people on a small piece of land. The places becomes noisy thus not favourable for people who want to be in a peaceful and noise free environment .Also as a result of traffic congestion, pollution levels will increase through the emission of toxic gasses into the air from car exhausts. This will negatively affect peoples' health and wellbeing. Thus in light of the above compact cities become less sustainable.

To add on compact cities results in the pollution of storm water systems, making them less sustainable. This is due to the greater degree of hard surfaces or impervious surfaces from increased density developments, rather than the absorption by a natural ground surface.

In conclusion it can be noted that to a greater extent compact cities are more sustainable than dispersed cities. This is so because compact cities comes with many advantages that dispersed cities do not offer for example reduction in temperatures, pollution and social interaction as highlighted by the above essay.

REFERENCES

Jacobs, J ,2000, The Death and Life of Great American Cities, Random House, New York City.
Breheny, M, 1995, The compact city and transport energy consumption. Transactions of the institute of British Geographers, 81-101.
Landry, C, 2006, The art of city-making, Routledge.
Gordon, P, and Richardson, H, 1997, Are compact cities a desirable planning goal? Journal of the American planning association, 63(1), 95-106.
Jenks, M, Burton, E and Williams, K. 1996, The Compact City: A Sustainable Urban Form, Spon Press, London.
Carmona, M, 2010, Public places, urban spaces: the dimensions of urban design, Routledge.
Rogers, R. and Gumuchdjian, P., 2000, Cities for Small Planet, Faber and Faber Limited, London.
Bekele, H, 2005. Urbanization and urban sprawl. Master of Science Thesis No, 294.
Hamel, P, 1993, City modernity and post- modernity, Canadian Journal of Urban Research, 2, pp.16-29.