Human Settlements Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Professor Peter W. Newton, CSIRO Building, Construction and Engineering, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06747 7
Emerging issues (continued)
Change in urban activities, transport and land use
Employment patterns are changing in our urban centres. More people are employed in service industries, working hours are no longer restricted from nine to five, and there are many multi-worker households. Households are engaging in more out-of-home activities. These trends lead to increases in travel plus increasing time pressures and complexity in travel patterns, making public transport use less attractive.
The population is ageing and average household size is falling. However, the anticipated greater call on public transport by an ageing population may not occur as the elderly are making a greater proportion of trips by car and maintaining their licences to drive. Indeed, social and recreational trips by retirees may increase car travel. Smaller households may result in more household vehicles, in total, as options for sharing are limited, and daily activity schedules more complex.
At the same time, freight vehicle trips are increasing. Reasons range from transport of construction materials for growing cities, to changes in logistics practice with 'just-in-time' delivery requiring extra trips for more frequent dispatch of smaller loads. Travel and traffic demand management measures to limit the impacts of growing road traffic on the built and natural environments, for example for greenhouse gas amelioration, will need to be tailored to these new circumstances.
E-business and e-transport
The impact of the communications revolution on transport is expected to be increasingly important. Intelligent transport systems and vehicles will have implications for traffic flow, demand management, safety and road pricing. Electronic toll collection is already in place as are freight tracking systems and traveller information systems. Tourists can hire smart vehicles with electronic guidance systems to steer them to their destinations.
E-business has some potential to limit the need for travel by increasing tele-working or replacing meetings with electronic conferences and replacing personal shopping with tele-orders. There will be a substitution of electronic documents and signatures for hard copy, or more efficient goods delivery, including domestic shopping. However e-business is equally likely to generate new goods and services movements, dispatch over greater distances due to sourcing of goods from further afield, and even extra business travel by people visiting new clients and suppliers.
Increased noise resulting from changes in urban activity
Extra noise is generated by extra people and by changes in work and leisure. Areas of cities previously well protected from noise pollution are being increasing affected. For example, the construction of a new runway at Sydney airport, necessitated by increased demand for air travel, has led to previously quiet suburbs experiencing aircraft noise. There is likely to be increased road traffic because of extra passenger, freight and delivery vehicle trips in all cities.
Moreover, environmental noise is extending over longer periods. Daytime traffic noise was once estimated over a 12-hour period, but now the 'day' extends for 18 hours or more. This is in part a result of the growth in industry and commerce but also a result of significant changes in work practices. Increasingly workers are involved in service industries and working longer hours; and the costs of plant and equipment plus deadlines mean that construction and other previously daytime activities continue into the night. Retail outlets, cafes and restaurants are adjusting to a workforce working all hours in the 24-hour city. While inner city residents may be more affected, these changes extend to the outskirts of cities where suburban residents may be disturbed at 3 am by garbage collection or large freight rigs heading into the city.
Fragile foundations: Australia's ageing infrastructure
High-speed rail, broadband networks and high-rise building will be significant new infrastructures in 21st century Australian settlement. Australia's economic performance and quality of life is, however, heavily dependent upon the standard of urban infrastructure laid down in the 19th and 20th centuries. The Langmore Report (Langmore 1988) was among the first of many to draw attention to the decline in public sector expenditure (capital and operating) on infrastructure. Over the past 40 years, national spending on public sector infrastructure generally has declined from 8% of gross domestic product to 2%, which is insufficient to keep pace with demand and obsolescence. This represents a problem for a country which has among the highest ratios of infrastructure to population in the world. The Institution of Engineers Australia recently warned that the corporatisation of the government departments and utilities that provide the services has put greater emphasis on the return on capital, often to the detriment of maintenance (IEAust 2000). Government trading enterprises are under pressure to maximise returns to government coffers, often by reduced spending. The Institution's report on infrastructure rated the nation's roads, bridges, railways, and water and sewerage networks as relatively poor. The best rating, was a C for national roads, which varied in quality from good to poor with selective investment in projects like the Pacific Highway. Suburban roads had excessive traffic and congestion, and rural roads rated a D. Worse still was the condition of the railways; the Melbourne to Sydney to Brisbane corridor rated an F minus, and the Institution warned that Australia cannot benefit from rail's potential without a substantial upgrading of intercapital services. Ageing sewer pipes were considered a major problem; many are 50 to 100 years old, and sewage treatment and disposal systems are often below community expectations. Sydney Water Corporation's oldest sewer pipes are more than a century old and lie below 19th century residential areas. The Corporation is responsible for 20 191 km of water pipes and 21 961 km of sewer pipes servicing four million people in Sydney, the Blue Mountains and the Illawarra. Another 150 km of new sewers and 130 km of water mains are added each year.
Sydney Water Corporation's costs for operating, maintaining and replacing water mains has increased from $273.6 million in 1995-96 to $364.6 million in 1998-99, and in 1999-2000, the Corporation spent more than $500 million maintaining and rebuilding the sewer and water system.
The social, economic and environmental implications of inadequate creation and maintenance of urban infrastructure is reflected in interruptions to gas supply (e.g. at the Longford plant) and electricity supply ('brown-outs'), issues of water availability and quality, train derailments, airport delays (especially out of Sydney), and traffic congestion.
Infrastructure impacts and adaptation to climate change
Reports from the Intergovernmental Panel on Climate Change (IPCC 2001) have established that human-induced climate change caused by the enhanced greenhouse effect is already occurring, and that future change is inevitable: 'it is not a question of whether the Earth's climate will change, but rather by how much, how fast and where' (Watson 2000). IPCC climate models project an increase in global mean surface temperature of between 1.6C and 6C between 1990 and 2100. These changes in temperature will be accompanied by changes in rainfall patterns, sea level rise and other factors such as snow and ice cover, ocean circulation and monsoons.
A level of uncertainty currently surrounds the possible implications of climate change on Australia's population and settlement, but impacts are likely in the following areas:
Flooding - recent forecasts by CSIRO's Climate Impact Group show that Australia could experience longer dry spells interspersed with heavier rainfall (Dr Peter Whetton, pers. comm., 2000).
The return period of heavy rainfall events may be reduced by a factor of between two and four if atmospheric CO2concentrations double. If the once in 400 years flood was to become the once in 100 years flood, simulations of combined potential residential and commercial damage suggest a tenfold increase in associated costs for urban areas in the Hawkesbury-Nepean region of Sydney (Minnery and Smith 1996).
Drought - for many parts of Australia, rainfall and water supply are generally adequate. However, the drier inland areas of Australia are vulnerable to potential water shortages during seasonal minimum and during droughts.
Drought affects human settlements in a number of ways. In regional areas, crop and stock losses result in loss of income for farmers and consequent repercussions for supporting townships and businesses. Environmental damage from drought, such as vegetation loss and soil erosion, threaten the sustainability of agricultural enterprises. In urban areas the impact is on water availability, with consequent restrictions imposed by water authorities.
Any additional water shortages arising from climate change would sharpen competition among various economic, social and environmental uses and hence increase the effective cost of water. Considerable demand arises from urban development and the diversion of large amounts of water for economic purposes such as mining and irrigated agriculture. This competition may be exacerbated by trends toward population growth, higher valuation of natural waters, and possibly shifts to more intensive farming systems. If, on the other hand, there were to be an increase in water availability as a result of climate change, it might well encourage demand for more irrigation, with obvious short-term benefits - although in the longer term this could lead to increased salinisation in semi-arid regions.
In central Australia, low rainfall and high evaporation forces the few towns - such as Alice Springs and Yulara - and other tourist centres, cattle station, and Indigenous and mining settlements to rely on desalinised brackish groundwater. Economic growth and population growth will put added pressure on these supplies, which are recharged in part by occasional heavy rainfall events.
Bushfires - Beer and Williams (1995) suggest an increase in fire danger over much of Australia, largely attributable to a decrease in relative humidity. Loss of life and damage to property due to bushfire is predominantly centred on Australia's urban centres.
Snowfall and winter tourism - increased temperatures will lead to a reduced fraction of precipitation falling as snow, higher snowlines, earlier spring snowmelt and a shorter snow season. An increasing frequency of poor snow seasons due to climate change could be expected to increase competition among Australian ski fields, and those located at lower altitudes may have to close down their operations, with knock-on effects for associated communities (Whetton et al. 1996).
Sea levels and coastal settlement - parts of Australia's coasts and rapidly growing coastal settlements and infrastructure are vulnerable to any increase in coastal flooding and erosion, which may occur from sea level rises in association with other meteorological changes, such as cyclone frequency and intensity and storm surges (McInnes and Hubbert 1996). Climate change and sea level rise are not well represented in current coastal management planning.