How many people make a good city? It’s not the size that matters, but how you use it

Australia’s population clock is, according to the Australian Bureau of Statistics, steadily ticking away at an overall total population increase of one person every 1 minute and 23 seconds.

Many are debating what the ideal population is for a country like Australia. But because most of this population growth is concentrated in our big cities, perhaps we should be thinking less about that and more about the ideal size of a city. Historically, there have been many theories on what this would be.

From Aristotle to Albanese

For Aristotle (384–322 BC), for instance, the key was balance. Cities had to contain a minimum number of groups, such as citizens and slaves, to work politically. Similarly, a city’s population had to be balanced against the size of the territory it drew its resources from to enable each citizen (but not slave) to have what he called a “good life”.

Aristotle reputedly drew on the constitutions of what were then known as city states. These aren’t directly comparable to today’s cities but do make for good test cases with which to examine urban models. City states of the time, in the vanguard of urban life as they were, were equivalent to small towns of today and less connected and more homogeneous.

During the 20th century, as the world’s population grew, planners around the world tried to deliberately limit the size of cities. But how did they decide on the ideal size?

Planning theorist Lewis Keeble wrote in the late 1950s that the ideal UK city size could be determined by setting the distance for citizens to reach the countryside. So, a resident in the centre of a town could reasonably be expected to walk to the edge of the city for a distance of two miles (3.2km).

In the lead-up to the 2016 federal election, Prime Minister Malcolm Turnbull aimed for a deal to be struck between all levels of government, to deliver suburbs where residents can get to school or work within 30 minutes. And in a speech to the National Press Club two years earlier, Labor’s shadow minister for cities, Anthony Albanese, said he was “particularly attracted” to the concept of the 30-minute city.

It’s not the size that matters

But a city’s liveability isn’t equal to its appeal for living and working in. Tokyo, the largest city in the world, will never top the liveability scale. Its infrastructure challenges are of a different order compared to Australia’s cities. The equivalent of Australia’s population passes through the ticket barriers of Shinjuku, its busiest station, in a week.

Under this concept, with a density of 50 people per hectare, the ideal city size would be 160,000. For a city, where the population would have access to public transport, Keeble estimated this would be around 4 million.

Keeble was the first to admit these calculations were naive. Yet a calculation of city size based on the biological limits of the human body, mixed with the use of public transport, echoes contemporary thinking. Cities that often top the liveability scale – such as Melbourne and Vancouver – are universally mid-sized (around 4-5 million people) with low population density.

More recently, in the late 1990s, the Italian physicist Cesare Marchetti’s term “the 30-minute city”, first proposed in a relatively obscure paper, has been drawn into policy language.

But these challenges are being managed quite successfully.

Originally Published by The Conversation, continue reading here.


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Prefab construction is a godsend for disaster response

Prefabricated construction techniques show promise as long-term solutions for rebuilding disaster zones in remote and rural locations, according to Monash University professor Mehrdad Arashpour.

As long as thought goes into the location of prefab buildings – such as their proximity to water sources – modular, off-site construction can be viable long-term residences in disaster zones, Dr Arashpour told The Fifth Estate.

Prefabricated, self-contained buildings are also sustainable options for short-term disaster relief as they can be continually reused, Dr Arashpour said. In disaster-prone locations, such as Japan, ready-made modules can be built cheaply, stockpiled until needed and then assembled at speed. Japanese prefab company Daiwa Lease, for example, has set up a production line in emerging Asian countries that can divert product to Japan when a disaster happens and homes are needed.

Critically, the modular, panellised nature of prefab construction means that buildings are reconfigurable and easily adapted to be used as temporary schools or medical clinics instead of housing, for example.

Another benefit of prefab buildings is that they can be installed with minimal skills and tools.

Sustainability benefits include a lower carbon footprint and high thermal performance, Dr Arashpour said.

He added that the thermal performance of most modules work best in cool climates, although they can be used in warmer locations.

Most prefab buildings are also easier to recycle because they are quick to dismantle.

Prefabricated construction techniques are finally getting attention after decades of failing to penetrate the industry in any meaningful way.

Dr Arashpour said prefab take-up would become an increasingly attractive option once a more integrated construction, manufacturing and transport process is established.

“We need high-precision manufacturing and this needs to mimicked at site, with the correct dimensions… We haven’t quite nailed the practical implementation.”

Originally Published by The Fifth Estate, continue reading here.

New resilience strategy highlights the disasters that could bring Sydney to a shuddering halt

AUSTRALIA’S largest metropolis has simply been “lucky” to avoid a city stopping disaster, a group of resilience experts have said.

But Sydney’s luck could be about to run out, and if the city isn’t felled by extreme heatwaves and terror attacks, more insidious creeping catastrophes such as housing affordability and chronic illness could do it in.

That’s the conclusion of a landmark analysis released on Tuesday that aims to shake Sydneysiders out of their stupor and prepare for a range of foreseeable disasters that could bring the city of five million to its knees.

The “Resilient Sydney” report, launched by City of Sydney Lord Mayor Clover Moore, details a slew of “acute shocks” and “chronic stresses” that could or are already occurring, and how the city can avoid falling foul of them.

Extreme heatwaves are one of the major disaster risks Sydney faces. Picture: Dr Roger Allison-Jones

Sydney is the second Australian city to sign up to the global 100 Resilient Cities program, Melbourne has had a head start of two years to get its act together. Backed by the Rockefeller Foundation, the program aims to help cities manage disruption and respond to disasters.

“What we mean by resilience is how we adapt, thrive and survive from shocks and stresses,” Beck Dawson, Sydney’s nattily titled chief resilience officer, told news.com.au.

“A shock can be a short, sharp disruption, like a flood for a terror attack, but a stress is a long, slow burning issue that can turn in to a disaster or magnify those other events because of the underlying vulnerabilities in the city.”

SYDNEY HAS BEEN “LUCKY” SO FAR

But the city is facing a double whammy of issues that could prevent it from coping in the face of disasters, either acute or chronic, Ms Dawson said.

One was the city’s fragmented government, with Sydney having no single city-wide council; the other was the false sense of security that can pervade a city that has faced fewer disasters than counterparts overseas.

Not that Sydney hasn’t faced its own shocks — the report lists 2014’s Lindt cafe siege, the Cronulla riots of 2005 and the 1998 disease pandemic that left the tap water of three million people contaminated as well as ongoing extreme weather.

However, the Harbour City hasn’t gone through the terrorist attacks or natural disasters that have befallen other 100 Resilient Cities members such as London, New York and Christchurch, said the executive director of the Sydney Business Chamber Patricia Forsythe.

Ageing infrastructure could undo the city in an extreme weather event. Picture: iStock

“Sydney has been so lucky up to now; often it’s said we’ve never been tested in terms of natural disasters or other issues that face other cities.

“But we have to ensure if we are ever tested we learn the lessons from other places and that is when businesses can’t open, when people don’t have jobs, when they are disrupted, that impact flows through not only those people if affect so many people. “

The report listed Sydney’s chronic stresses as the growing demand on health services, housing affordability, social cohesion, lack of employment diversity, financial inequity, chronic illnesses, transport diversity and drug and alcohol abuse.

The acute shocks, listed below, were harder, sharper hits that could throw the city into crisis at a moment’s notice.

THE ACUTE SHOCKS THAT COULD SPELL DISASTER

1. Extreme weather

2. Financial institution failure

3. Infrastructure ageing and failure

4. Terror attack

5. Cyber terrorism

It’s a similar problem to Melbourne which released its resilience strategy in 2016. It concluded the city’s acute shocks could be bushfires, floods, heatwaves, pandemics, infrastructure-related emergencies and cybercrime. A rapidly growing population was a chronic stress for Melbourne.

Organisers of the report recommended households download the Get Prepared app, developed with the Red Cross and insurer IAG, which enables Sydneysiders to store emergency contacts and identify their nearest emergency services.

Ultimately, Ms Dawson said, her job revolved around three key questions: “what will stop this city, who will bear the risks and what will the cost be when it goes wrong?”

Originally Published by News.com.au – read full article here.

Why temperatures at night are going up around the world and what we can do about it

History was made in the Middle East on June 28 when the world’s hottest night on record was set in Quriyat, Oman with the overnight “low” dropping to 42.6 degrees Celsius.

Oman’s hot night is just one of many temperature records to be smashed in the past few weeks.

Individual location records have been broken in the US, Russia, Canada, Scotland, Armenia and Georgia.

Africa could have reached its highest ever reliably recorded temperature of 51.3C in Ourargla, Algeria on July 5.

The World Meteorological Organisation recognises 55C as the highest temperature for Africa, recorded at Kebili, Tunisia on July 7, 1931.

James Goldie’s research is investigating how dangerously hot days are identified and how well they can predict public health impacts.

But there is widespread scepticism about the record’s accuracy because the temperatures recorded before the 1950s are mysteriously higher than anything to have come after them.

When it comes to heatwaves, the night-time temperature is important. If it stays above the mid-20s, overnight sleep can become difficult because the body needs to actively work to cool itself down.

University of New South Wales PhD student James Goldie, who is researching how temperature relates to health, said comfortable overnight temperatures were important in making sure people got a restful sleep.

“[It] is when our muscles recover from exercise. It’s when our brains consolidate memories,” he said.

“When night-time temperatures continue to be hot, when that heat just runs all the way through the night and onto the next day, we don’t get that recovery, and that’s when heat stress really starts to build up.”

Mr Goldie said heatwaves could be a real danger.

“They’re like rips at the beach; if you respect them, they’re tough but they’re manageable. If you don’t respect them, they can kill people,” he said.

Over the past few weeks Canada has been experiencing summer heatwaves, with local news outlets now reporting up to 70 heat-related deaths.

Nights are getting warmer

Research published in the International Journal of Climatology last year found night-time temperatures were increasing more rapidly than daytime temperatures.

According to the findings, minimum temperatures have been increasing at a rate of about 0.07 degrees per decade, compared with about 0.05 degrees per decade for maximum temperatures globally, for the period from 1960 to 2009.

Researchers proposed this was because night-time temperatures were more easily affected by an increase in greenhouse gasses.

Australia is not immune from warmer nights — our night-time temperatures have been increasing over the past 50 years and they are expected to continue to rise.

As part of the CSIRO’s Climate Change in Australia project, a threshold calculator has been created for the public to explore future climate scenarios.

The tool suggests an increase in over-25C degree nights into the next century, to different extents based on the different models and emissions scenarios.

Mr Goldie said some of the impacts of heatwaves from climate change could not be avoided.

“They’re happening. But we can control how bad they get, and the actions we take to reduce CO2 now will save people’s lives later down the road,” he said.

The World Health Organisation has said high greenhouse emission scenarios are projected to increase heat-related deaths in Oman, where it was so hot a few weeks ago.

What can we do about it?

Stephanie Jacobs is a PhD candidate working on different ways to mitigate the effects of heatwaves.

Aside from reducing greenhouse gas emissions, there are things we can do to mitigate the impact ofheatwaves.

Monash University climate scientist Stephanie Jacobs said the best strategy to help reduce night-time temperatures was to plant trees and vegetation and keep them watered.

“When there are no trees, the sunlight heats up the ground,” she said.

“When there are trees, the energy from the sun is diverted to helping the water in plants evapotranspirate instead of heating the surface, so it becomes cooler.

“As a result, the ground holds less energy during the day and then emits less heat at night.”

Ms Jacobs said tree planting could be hard in desert environments, but it could be effective in cities.

“Plant more parks, gardens [and] lots of trees … it’s been found that a mix of vegetation is the best because different plants have different benefits,” she said.

Making buildings more reflective was another action Ms Jacobs suggested could assist in cooling temperatures.

“What I’ve looked at in my research is if all of the rooftops in Melbourne were white, and we basically turn Melbourne into a giant Santorini [where white-painted houses reflect dazzling light],” Ms Jacobs said.

Originally Published by ABC News, continue reading here.

According to study these are the key features a ‘happy city’ needs

City planners and designers want to build cities that are liveable, healthy and smart. Yet, in the abundance of research and guidelines on how to make healthy cities, happiness seems to be missing.

Research shows urban environments have an impact on our well-being and mental health, affect our behaviour and moods, interactions, day-to-day lives and even alter how our brain functions.

Our recent study found people associate their happiness with particular natural and built elements in the environment. This highlights how we can improve the design of cities to enhance people’s happiness.

Searching Instagram

In the first part of our study, we searched Instagram for images of the city people associated with happiness. We did this using four hashtags:

  • #cityhappy
  • #happycity
  • #cityofhappiness
  • #urbanhappiness

The images came from all corners of the globe, with no geographical limitation.

We sifted through hundreds of images, excluding photographs that were “selfies”, had non-urban attributes, or if they included people posing. Overall, we narrowed it down to 196 images, all of which exhibited characteristics of an urban area.

We found photographs tagged with one of the above hashtags consistently featured particular design elements. These were:

  • open space
  • natural elements (vegetation, sand, rocks)
  • historic or heritage buildings
  • colour
  • medium density buildings (up to six storeys)
  • water
  • human scale buildings (horizontal rather than vertical).

The same features came up time and again, irrespective of demographic and geographic location. This supports the idea there may be universal urban features that enhance happiness.

We then tested these themes on Brisbane residents through an online questionnaire.

Online survey

Twenty-two people took part in the online survey. They were asked to evaluate their happiness relative to different features, characteristics and images of areas in Brisbane. The survey comprised a series of multiple choice, selection and rating questions.

The results showed participants associated happiness with the same features as those who had posted on Instagram using the above hashtags. Most common to happiness was open space (86 per cent of respondents) and natural lighting (81 per cent).

Natural spaces with greenery such as parks, gardens and areas with trees, as well as areas that had water, had a significant positive impact on respondents’ happiness. Proximity to facilities, walkability of the area, green belts and views to mountains were also significant factors.

Historic or heritage character buildings ranked pretty highly (72 per cent), over the more modern style buildings. Laneways also scored pretty highly (72 per cent) as did views of the city (68 per cent) and colour (59 per cent). We noticed people liked other things, such as the materials used on sidewalks, roads and building facades.

This pilot study confirms there are specific elements which can be incorporated and factored into the planning and design of cities to enhance people’s happiness. Our further research is currently building on these initial findings, focusing on the relationship between density, urban design and happiness.

How can we use this?

Happiness is a major component of human well-being. But it isn’t factored into the widely recognised quality of life (including health, well-being and a number of economic factors) and liveability (including the standard of living) surveys of cities.

Some evidence suggests average happiness levels in Western nations haven’t improved in the last 68 years (since 1950). This is despite first-world incomes more than doubling in that time.

Happiness studies look at the links between human “subjective well-being” and the environment. We can determine people’s preferences, subjective view and association with elements of the built environment through research, and then apply the lessons to design to improve the quality of the urban environment.

Our research highlights the key elements to be cognisant of in urban transformation projects and designing for future urban areas. These findings show we can use such knowledge and apply this to existing cities to retrofit them for happiness.

People are increasingly leaving the broad acre, single detached home to live in denser, more compact urban areas. There are many benefits to this urban settlement. But to make this lifestyle compatible with human happiness and foster mental health, the design, planning and governing policy needs to consider such factors.

Originally Published by Domain.com.au, continue reading here.