Thursday 22 March 2012

The Floatable City

We have already determined that the earth's sea levels are presently rising and have been rising since the advent of the earth's current Interglacial (warming) phase known as the Holocene Epoch, which commenced around 15,000 ybp and that sea levels will continue to rise as the earth warms up and its ice sheets contract, during this naturally induced warming phase (read our previous blog on "Global Warming is inevitable": http://mbharchitectssa.blogspot.com/2012/02/asarchitects-today-we-need-to-have-at.html)

According to an estimate by the IPCC (Intergovernmental Panel on Climate Change), sea levels may rise up to 59cm during the 21st century. A 1m rise has not been ruled out.
 
This means that two facts remain to be dealt with. One, that buildings in low level or coastal conurbations will be ever increasingly exposed to flooding in the near future and, two, that the long term rise and fall of the sea's levels during the earth's Glacial and Interglacial cycles, is estimated at an average range of between 4 to 6m.
Now, as previously mentioned, the last time the earth's sea levels rose by 6m, during the peak of the Eemian Interglacial approximately 125,000 ybp, our human conurbations in coastal regions, were not yet existent. So, as a species, we have never faced such a threat before.

Given the above impending intermittent flooding and long term rise in sea levels of potentially up to 6m above the current level, conceivably over the next few thousand years, we, as architects, have three primary options. One option, and possibly the most extreme option, is to advise our clients against developing in coastal or low lying regions which could be affected by a 6m rise in sea levels, but due to present day settlement already located within these zones, this is not entirely practical nor feasible. A second option is to design buildings sufficiently elevated on fixed plinths to accommodate the inevitable rise in sea levels, should our clients still insist on developing within these risk zones.

The third option would be that we, as architects, start creating floatable buildings and cities, as opposed to floodable building and cities, within these low lying and/or coastal regions, with plinths that provide buoyancy and sufficient vertical movement range, to initially be able to absorb any potential flash flooding by rising with the water levels, and to eventually be able to accommodate a 6m rise in sea levels.

The floating city and floating buildings are already a viable concept in many parts of the world, especially in extreme low lying countries such as Holland. But the concept of floatable cities or buildings, should not be confused with floating cities or buildings. There is a fundamental difference between cities and building constructed to become buoyant in the event of catastrophe, and floating cities or buildings, which are purposefully constructed at sea or on lakes for that purpose exclusively, such as for example the Lake Huron Floating House .

What we are talking about here, are buildings constructed with plinths similar to a ship's hull, capable of becoming buoyant during a flood, yet still anchored to the earth by means of fixed mechanical foundations. These buildings would be analogous of ships sitting in a dry dock, awaiting the rising waters.

If one considers the enormity of ocean liners that exist today, such as The Allure of the Seas and The Oasis of the Seas, which could both be regarded as floating buildings, then constructing our future floatable building on dry ground similar to these principals, are not all that far-fetched. The only difference will be that a floatable building won't be going anywhere except up or down as required in the event of a catastrophical rising of water levels.


Sunday 11 March 2012

Formation of South African Chapter of the Congress for the New Urbanism

South African built environment professionals interested in joining the formation of the South African Interest Group and/or Chapter of The CNU (Congress for the New Urbanism) please contact Manus Heunis on mbharchitectssa@gmail.com

Very briefly, the CNU is head quartered in Chicago, Illinois in the USA, and an organisation which enjoys worldwide support for its efforts in and guidance on promoting more sustainable urban environments by means of, amongst many others, more environmentally sympathetic town planning principals, reduction of urban sprawl by means of mixed use developments and creating transit oriented and pedestrian friendly cities and neighbourhoods, all of which ultimately lead to a reduced urban carbon foot print.

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For more info on what the CNU is all about, click on the link provided below

http://www.cnu.org/who_we_are