Here's how Australia's cities have grown over the last 30 years

More than any other Australian city, Melbourne has led a 30-year turnaround in inner-city density (red indicates increases and blue decreases in density as persons per square kilometre). Image: author provided.

Since settlement, Australian cities have been shaped and reshaped by history, infrastructure, natural landscapes and – importantly – policy.

So, have our cities changed much in the last 30 years? Have consolidation policies had any effect? Have we contained sprawl? Yes, probably and maybe, according to our newly published research.

Reviving the centre

The great Australian baby boomer dream of home ownership caused our cities to spread out during the second half of the 20th century. Urban fringes expanded with affordable land releases, large residential blocks and cheap private transport.

By the 1980s, across Australia’s cities, the urban fringes were ever-expanding. Inner areas had become sparsely populated “doughnut cities”.

By the end of that decade urban researchers, planners, geographers and economists began to warn of looming environmental, social and housing affordability problems due to unrestrained sprawling growth.


Governments responded swiftly, focusing policy attention on urban consolidation through programs such as Greenstreet and Building Better Cities. Concerned individuals formed groups such as Smart Growth and New Urbanism to promote inner-city development and increased urban density.

Since this time, large- and small-scale policy interventions have attempted to repopulate the inner- and middle-urban areas. The common policy goal has been to encourage more compact, less sprawling cities. Subdivision, dual occupancy, infill development, smaller block sizes, inner-city apartments and the repurposing of non-residential buildings have all been used.

Mapping the changes

In a newly published paper, we map the changing shape of Australia’s five largest mainland cities (Sydney, Melbourne, Brisbane, Perth, Adelaide) from 1981 to 2011.

Across each of these cities, which together are home to 60 per cent of Australians, there has been substantial, suburbanisation and re-urbanisation. In the last 20 years this has resulted in a repopulation of inner cities.

In Melbourne’s case, the return to the inner city has been particularly pronounced in the last decade. Here, the population jumped from around 3,000 to 4,000 people per km². The extent of this change is visualised in the chart below.

Melbourne may well be the exemplar for inner-city rebirth. More than any other Australian city it demonstrates the 30-year turnaround from inner-city decline to densification.

Between 1981 and 1991 Melbourne became a classic “doughnut city”: population declining in inner areas, density increasing in the middle-ring suburbs, and growth steady in the outer suburbs. For example, in the inner 5km ring there was a decrease during this time of almost 200 people per km².

From 1991 to 2001, even though growth was still focused on the middle and outer areas, the inner area began to be repopulated. Overall, between 1981 and 2011 there were approximately 1,500 more people per square kilometre living in the inner 5km ring.

Over the last decade, greenfield development, infill and urban regeneration have increased urban density throughout Melbourne – as shown in the five-yearly map animation below.

Changes in Melbourne population density (persons/km² over the 30 years to 2011: red is increasing, blue is decreasing). Image: author provided.

While the turnarounds in Sydney, Brisbane, Adelaide and Perth have been less marked than in Melbourne, they are all no longer “doughnut cities”. This means that where people live in these cities has changed.

Australia’s cities are now more densely populated – and we are much more likely to live in inner areas than we were 30 years ago.

A result of government policy?

We can probably attribute the changes in where urban Australians live to government consolidation policies.

The policy focus throughout the late 1980s and early 1990s was based on incentives to repopulate inner and middle areas.

Policies were changed from 2000 to increase population density across whole metropolitan areas. State and territory strategic plans aimed to promote urban consolidation, with a focus on the inner city.

State and territory plans now focus much more on specific zones throughout the whole of the city, including former industrial areas and surplus government land. New housing development occurs within these defined zones, particularly around transport and areas with urban-renewal potential.

South Australia’s 30-Year Plan for Greater Adelaide targets growth in “current urban lands”, along major transport corridors and hubs. Similarly, the Plan Melbourne – Metropolitan Planning Strategy plans to establish the “20-minute neighbourhood”, contain new housing within existing urban boundaries, and focus development in new urban renewal precincts.

The map visualisations reinforce the scale of this absolute growth across each of the five major Australian cities over the last 30 years.

Have we contained sprawl?

Our research would suggest urban-consolidation policies have slowed but not prevented sprawl, especially in the faster-growing cities like Melbourne, Brisbane, Perth and Sydney.

So, have we reached the point at which our cities are full? How can we accommodate future population growth? And do we need to focus our attention on new urban areas?

Containing and, more importantly, controlling sprawl may present the next big challenge.

Neil Coffee is a senior research fellow in health geography at the University of South AustraliaEmma Baker is associate professor at the School of Architecture and Built Environment, and Jarrod Lange a senior research consultant (GIS) in the Hugo Centre for Migration and Population Research, at the University of Adelaide.

This article was originally published on The Conversation. Read the original article.

Two of the graphics in this article were updated to clarify that population density changes were shown in persons per square kilometre, consistent with the measure used in the text.The Conversation

 
 
 
 

This fun map allows you to see what a nuclear detonation would do to any city on Earth

A 1971 nuclear test at Mururoa atoll. Image: Getty.

In 1984, the BBC broadcast Threads, a documentary-style drama in which a young Sheffield couple rush to get married because of an unplanned pregnancy, but never quite get round to it because half way through the film the Soviets drop a nuclear bomb on Sheffield. Jimmy, we assume, is killed in the blast (he just disappears, never to be seen again); Ruth survives, but dies of old age 10 years later, while still in her early 30s, leaving her daughter to find for herself in a post-apocalyptic wasteland.

It’s horrifying. It’s so horrifying I’ve never seen the whole thing, even though it’s an incredibly good film which is freely available online, because I once watched the 10 minutes from the middle of the film which show the bomb actually going off and it genuinely gave me nightmares for a month.

In my mind, I suppose, I’d always imagined that being nuked would be a reasonably clean way to go – a bright light, a rushing noise and then whatever happened next wasn’t your problem. Threads taught me that maybe I had a rose-tinted view of nuclear holocaust.

Anyway. In the event you’d like to check what a nuke would do to the real Sheffield, the helpful NukeMap website has the answer.

It shows that dropping a bomb of the same size as the one the US used on Hiroshima in 1945 – a relatively diddly 15kt – would probably kill around 76,500 people:

Those within the central yellow and red circles would be likely to die instantly, due to fireball or air pressure. In the green circle, the radiation would kill at least half the population over a period of hours, days or weeks. In the grey, the thing most likely to kill you would be the collapse of your house, thanks to the air blast, while those in the outer, orange circle would most likely to get away with third degree burns.

Other than that, it’d be quite a nice day.

“Little boy”, the bomb dropped on Hiroshima, was tiny, by the standards of the bombs out there in the world today, of course – but don’t worry, because NukeMap lets you try bigger bombs on for size, too.

The largest bomb in the US arsenal at present is the B-83 which, weighing in at 1.2Mt, is about 80 times the size of Little Boy. Detonate that, and the map has to zoom out, quite a lot.

That’s an estimated 303,000 dead, around a quarter of the population of South Yorkshire. Another 400,000 are injured.

The biggest bomb of all in this fictional arsenal is the USSRS’s 100Mt Tsar Bomba, which was designed but never tested. (The smaller 50MT variety was tested in 1951.) Here’s what that would do:

Around 1.5m dead; 4.7m injured. Bloody hell.

We don’t have to stick to Sheffield, of course. Here’s what the same bomb would do to London:

(Near universal fatalities in zones 1 & 2. Widespread death as far as St Albans and Sevenoaks. Third degree burns in Brighton and Milton Keynes. Over 5.9m dead; another 6m injured.)

Everyone in this orange circle is definitely dead.

Or New York:

(More than 8m dead; another 6.7m injured. Fatalities effectively universal in Lower Manhattan, Downtown Brooklyn, Williamsburg, and Hoboken.)

Or, since it’s the biggest city in the world, Tokyo:

(Nearly 14m dead. Another 14.5m injured. By way of comparison, the estimated death toll of the Hiroshima bombing was somewhere between 90,000 and 146,000.)

I’m going to stop there. But if you’re feeling morbid, you can drop a bomb of any size on any area of earth, just to see what happens.


And whatever you do though: do not watch Threads. Just trust me on this.

Jonn Elledge is the editor of CityMetric. He is on Twitter as @jonnelledge and also has a Facebook page now for some reason. 

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