Australia is an extremely urbanised country; about 85 per cent of the population lives in coastal areas, and most of these people live in urban areas with populations of over 100 000 people. This accounts for only about 1 % of Australia's total landmass. This level of urban growth is putting much pressure on cities to keep up with the needs of the growing populations. Though some areas of cities are being subjected to urban growth, other areas may be experiencing the effects urban decline. The suburb of Pyrmont-Ultimo in Sydney is a good example of urban growth and decline and its geological processes.
Urban growth is the increasing size of a city either in terms of an increase in population or an increase in its extent through the creation of new suburbs. This has created many issues and has impacted both the physical and built environment in a number of ways.
The natural environment suffers and is replaced as more space is required to build houses and the development of industry to accommodate the ever-increasing population.
Pyrmont-Ultimo is an example of a highly built area with little 'green space' and the amount of open space per resident in 2004 was below the City of Sydney's council which was generally about 2.8 hectares(28sqm) per person but the actual ratio was only half that(14sqm per person). The increase in population also worsens traffic congestion, pollution and sewerage disposal further contributing to the destruction of the natural environment and ecosystems. Strain on infrastructure is also evident where large populations of people demand more resources and services. These needs include access to amenities such as quality housing, transport systems, roads, schools, hospitals and police and fire services.
Urban decline is when changing land uses brought about by changing locations of activities within the city causes activities to move elsewhere, leaving former factories and warehouse areas abandoned causing them to fall into a state of disrepair. This leaves parts of the city derelict and unused taking up unnecessary space that could be used for residential apartments, industry or green space. This movement of factories and workplaces results in unemployment impacting on the population of the area causing it to decrease therefore introducing decentralisation, urban sprawl and urban decay.
A number of geographical processes take place in urbanisation and counter-urbanisation, whether they are the effects taking place due to urban growth and decline or the actions being done to countermeasure the effects. Some processes include urban decay, urban renewal, urban sprawl and urban consolidation.
The decentralisation process, where people living in inner-city areas move to the outer suburbs due to the re-locating of factories, shops and offices to the outer areas of the city results in urban decay. Abandoned former factories, shops and buildings start to decay and become derelict and useless due to disuse and no maintenance. This process of decentralisation and urban decay occurred in Pyrmont-Ultimo in the 1950s as industry started to move out into the suburbs which caused a major decline in population. By the 1990s Pyrmont-Ultimo's population had decreased to approximately 900 residents from the 30000 people living there in 1900s.
Urban renewal is the process used to combat the effects of urban decay and decline. The rejuvenation of old buildings, roads, public spaces and improved infrastructure encourages more people to move back into those areas. People moving into these areas have bought older homes and renovated them, this process is called gentrification. An area which was once unused and derelict now thrives with industry, new open space and people, which go towards economical and social benefit. 'The Better Cities' program organised the renewal and refurbishment of the Pyrmont-Ultimo area attracting high-tech clean industry such as media companies Channel 10, Nova and Foxtel and a residence of mostly young singles and couples with no children introducing a thriving community to the once urban decayed area.
The traditional Australian belief that 'every Australian is entitled to own a home on a quarter acre block' is one of the factors contributing to urban sprawl. Urban sprawl is the expanding of a city and taking up a large area of land for a given population which means infrastructure and services such as roads, water, sewerage, telephones, electricity and gas lines must be extended at great cost to the community. Urban sprawl also results in the loss of natural environment and ecosystems leaving less green space.
The developing of high-rise apartments and high density housing are used to counter the effects of urban sprawl through a process called urban consolidation. This planning strategy can decrease some of the infrastructure and equity problems saving the community time and money and also preserving some of the green space. Urban consolidation allows more people to live in a smaller area of land but in a more compacted style.
The problem of consuming finite resources is that there won't be any left for use of future generations, which brings up the issue of ecological sustainability. The government has initiated strategies and plans for achieving ecologically sustainable development such as encouraging green initiatives including recycling, consumption and water management schemes. For sustainability to occur, all governments and industries, as well as people, need to reduce the ecological impact of human activities. Urban consolidation is contributing to ecologically sustainable development by reducing the space needed to support a given population therefore decreasing the amount of resources being consumed and aids in the preservation of ecosystems and the environment.
The ecological footprint is a measure of human demand on the earth's ecosystems. It compares human demand with planet Earth's ecological capacity to regenerate. In 2005, it was estimated that Sydney's ecological footprint covered 49 per cent of NSW and with the current rate of growth, it is predicted that by the year 2031, Sydney's footprint will cover about 95% of NSW. To reduce this 'mark' left on the environment, communal cooperation is required in the following of ' green' government strategies such as water restrictions, use of energy efficient appliances, installation of rain-water tanks, recycling and the use of renewable energy sources.
Urban growth and decline occurs in about every urbanised country on Earth and can lead to geographical processes that cause the physical and built environment to destabilise such as urban decay and urban sprawl. But with new strategies and a 'green' state of mind, the effects of the environment can be neutralised through public, industrial and government cooperation in the processes utilised to combat the effects of urban growth and decline such as urban consolidation, urban renewal and ecologically sustainable development practices to ensure a clean, resourceful environments for present generations and future ones still to come.