Dear OwenWhat about affordable cities? there are several cities in the world today that nobody but the extreme rich can afford. They include London, New York, Paris Tokyo SydneyPeople who work there have to live outside and they will only do it if they get enough money to pay for transportCheersVincent Gray
75 Silverstream Road
Phone/Fax 064 4 9735939
"To kill an error is as good a service
as, and sometimes better than, the
establishing of a new truth or fact"
Charles Darwin"----- Original Message -----From: Owen McShaneTo: Owen McShaneSent: Friday, February 25, 2011 4:01 PMSubject: [climatescience] Digest – the Case for Resilient Cities.What kind of Cities do we Want?Sustainable Cities, Liveable Cities or Resilient Cities?One outcome of the dreadful earthquake that has severely damaged so much of Central Christchurch, taken so many lives, and terrified so many residents of the whole urban area, is whether the Central Area should be rebuilt, abandoned for some other location, or seized on as an opportunity to set new standards in sustainability, urban design, energy efficiency, or whatever ideal urban form takes your fancy.While some might think it is crass to even be pondering such matters, rather than focusing on saving lives and cleaning up the mess, many people in Christchurch are asking these kinds of questions about their urban area while many throughout the country are asking similar questions about the future of their own towns and cities.The Auckland Council's Draft Annual Plan is open for consultation on Monday 28th of February, and it is almost certain that many submitters will raise these kinds of issues.Let's put the issue of Sustainable Cities to one side because the word means everything, and hence nothing. However, it is worth mentioning that many Christchurch leaders are worried by the prospect of a mass population exodus which would surely threaten the ongoing sustainability of the urban economy.Liveable CitiesMany of Auckander's leaders are thrilled by the recent official ranking of Auckland as the tenth most liveable city in the world, and have announced their determination to make Auckland even more "liveable" than it is now.However this quote from a US urban blog should give us pause:Much of the highly touted liveability of Portland has come at the expense of making it unliveable, that is, unaffordable, to anyone without a six figure income. The creative and professional classes thrive in Portland because they are the only ones who can afford it, and they are the ones who appreciate the development style the city has tried to mandate. But what about the broad working class? Is there a role for the warehouse or factory worker in this city model? One of the great things about Indianapolis is its affordability to people with a wide range of incomes, and it would be a shame to see that lost in a wave of transit oriented gentrification.For more go to:See where I first raised this issue of "rich man's liveabiility" here:And how it was then picked up, and, thankfully, quantified here:Resilient Cities.
Many of us watched the devastation caused by the Queensland floods and were soon caught up in debates about the reason for these extreme weather events, and whether it could happen here. The combination of a strong El Nina and the Pacific Decadal Oscillation and the incipient Maunder minimum mean such event will be more common and more extreme than we have become used to since the similar combination of 1917/18.However, Phil McDermott, on his blog Cities Matter was quick to comprehend the lessons to be learned by our political leaders and urban planners.He opens his blog comment of with:An age of extreme events?Without debating whether an increase in the frequency of extreme events reflects climate warming , such events can be catastrophic when they impact on densely populated areas. Natural disturbances, whether geophysical (tsunami, earthquakes, mudslides) or climatic (flooding, hurricane strength winds, tidal surges), become disasters if they strike heavily populated centres.So do human acts of aggression. The tactic of terrorising civilian populations taken to new heights in the bombing raids of the Second World War and adopted by today’s extremists is most effective – and destructive - when directed at the heart of major cities.Later in the post Phil sets out the following vulnerabilities generated by the current "compact city" planning paradigm::
- It relies on sophisticated, centralised interdependent systems of services. This creates greater capacity for disruption when any one part fails. Economies of scale in utilities may come with increased risk of failure under duress. This applies to sewage treatment infrastructure, communications, water, energy distribution, and power supplies. It also applies to public transport systems.
- Poorly designed intensification reduces permeable surfaces, intensifying flood impacts.
- Converting brownfield and even greenfield sites (such as undeveloped urban space) to housing or mixed use reduces the safety valve of open space and increases vulnerability associated with the concentration of buildings and populations.
- Crowding more people into smaller spaces around constrained road capacity reduces prospects for rapid evacuation from the city or into safe structures and areas.
- Lifting the density of buildings increases the consequential impacts of severe events by such things as the collapse of structures, the spread of fire, and the transmission of disease.
- Mixing uses increases the risk of injury and destruction when people live close to premises where hazardous and flammable goods may be stored. Gas, chemical cleaners, and fuel are obvious examples.
- Reducing the space available reduces the capacity of people – households and communities – to fend for themselves, particularly if the consequences of a disruptive event are prolonged.Looking over these issues, it is unsurprising that our past history of increasing prosperity was a history of reducing urban densities even as rural-urban migration pushed up city populations.Read the whole post here:You might think he was setting out a list of lessons to be learned from Christchurch – but that "extreme event" was still in the future. A few days later, Phil responded to this tragedy with a second blog post, that picked up the same theme, titled "A Cruel Blow to a Beautiful City".It begins:Christchurch is reeling after the latest earthquake. Most of us can just look on with the sense of helplessness that distance brings. To see the centre of a modern city, one of ours, so devastated, its people so vulnerable and suffering is numbing.Today, tomorrow, and for some time to come the search for survivors and the cleanup will go on. We will hear stories of miraculous survival, heroism, and tragic loss.And then, as the city looks once more to recovery and rebuilding, we might look for the lessons to be learned. We cannot resist the power of earthquakes, hurricanes, tsunami, and the like. But we can perhaps limit the devastation that accompanies them.The implosion of many of Christchurch’s beautiful heritage buildings is a tragedy on its own, the wiping from the landscape of much of the City’s and nation’s history. But seeing the collapse of more modern buildings is sobering.What are the lessons of architecture and engineering that might be drawn from this? How much resistance can we realistically build into our structures? Or should we be thinking less rigidly, and explore designs that deflect or reduce the impacts when buildings are faced with irresistible forces? Should we think more about the survival of the people in and around buildings and less about the survival of the structures? Are there innovations in design that offer refuge, protection, and escape even if walls crumble and floors collapse?And what can urban designers and planners take from this devastation?What does it tell us about the importance of space in the central city, of wide boulevards, generous parks, and civic squares? About the need for more space, not less? The centre of Christchurch is still relatively open, and perhaps that has saved some lives. It was possible to take refuge in the streets, the squares, and the parks.This event must surely erode planners’ resistance to the decentralisation that is the mark of a prosperous, modern city, that makes it that little bit more liveable, and so much more resilient in the face of disaster? Perhaps we should be thankful that a diminishing share of Christchurch’s people actually works in the CBD – today just 26% of the total. And that not too many dwellings – and residents -- had been crammed into retrofitted buildings or high rise apartments assembled in inner city precincts.Read the whole post here:It does seem to me that our planners should stop worrying about sea levels rises that MIGHT, or might not, happen in 100 years – with plenty of warning – and start thinking more about making our cities resilient in the face of catastrophic events which we know can happen tomorrow – cyclones, volcanoes, earthquakes and tsunumai.E.g. Don’t put our motorways in tunnels below sea level. Don’t further intensify the central city, especially near the harbour edge.
I suspect that, given the trauma in Christchurch, the city will be re-built as a multi-nucleic low-rise decentralised urban area.
No matter how good the structural engineering, many Christchurch people will now be reluctant to work in buildings more than a few stories high. And any CBD will probably be built somewhere else – or parts of it will be – to avoid liquefaction.The Cathedral and its Square are potent symbols of Christchurch – as the Eiffel Tower is for Paris – and may be worth rebuilding for that emotional context.
But the new Auckland Council should take note that all cities in NZ are prone to catastrophe, and the forthcoming "Annual Plan" and “Spatial Plan” should embody this reality.However, the proper debate should not be as simple-minded as "high rise vs low rise" or "old vs modern". I suspect that liquefaction will have contributed to the collapse of some of the modern strong buildings. In the Kyoto earthquake some high rise blocks simple fell over but remained in one piece because of the total collapse of the ground under the building. One advantage of low-rise buildings is that people can get out of them quickly and there is less “stuff” to fall down on top of them.
Then there is the furniture inside the building. If all the bookshelves in a school library all end up against one wall it’s not very nice for the kids inside. Fortunately, in the Alaskan earthquake, where this happened, the kids had just gone home. The quake struck at 3.30.
Anyhow, these sort of problems and issues are not solved by sets of simple rules but by the application of skill, experience and wisdom. We can only hope that this dreadful event in Christchurch will provide an opportunity for urban policy makers and engineers to gain all three.Of course, some enthusiasts will want to see Christchurch rebuilt in their own utopian image, presumably driven by special regulation. Some draw on the precedent of Napier which was rebuilt after the Napier earthquake of 1931 with an "enduring Art Deco theme."
But in those days there was not even a Town and Country Planning Act to regulate urban design. Art Deco was all the rage at the time, and I suspect the few architects who were in Napier during the thirties seized the opportunity to demonstrate their flair and trendiness.
If anyone tries to impose a new set of objectives or design guidelines on Christchurch, the communities of the urban area, will have to go through the lengthy LTCCP and RMA processes, presumably with an embargo in place while the new regulatory regiime is all sorted out.
This is what happened (or was tried) in New Orleans and resulted in a couple of hundred thousand households departing for places where they were able to re-house themselves without waiting for bureaucratic consensus.
So I believe any “world leader” guide-lines would have to implemented solely by persuasion and involve no extra costs of DURT (delay, uncertainty, regulation and tax).
That is surely the lesson to be learned from the rebuilding of Napier.Owen McShane1104 Oneriri Rd, R.D. 2Kaiwaka, Northland, New Zealand. 057364 9 431 2775