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Green Cities. April 2005
Is a green city possible? - a response.
There has traditionally been a two-pronged
argument in this cause: One is for the dispersed city where
most people have large sub-urban blocks so they can, in theory,
grow their own vegetables and minor crops. Kahlil Gabran,
in The Prophet, laments that the people of Orphalese live
within the city walls - because of a fear from attack, a very
real danger across old Europe:
Would that I could gather your houses
into my hand, and like a sower scatter them in the forest
and meadow.
Would the valleys were your streets, and the green paths
your alleys, that you might seek one another through vineyards,
and come with the fragrance of the earth in your garments.
But, if we all lived in this manner, with
houses dotted amongst the hills and valleys, the cost of providing
the road, the sewerage, communications, power and water infrastructure
would be enormous. Cities would be a sprawling mass and would,
in reality, look like a typical low-density suburban American
or Australian city of today, connected by 8-lane freeways.
A more sustainable vision of living together
may be the defined high density cluster of persons, separated
by tracts of green land. These nodes may range from the 'village'
of 10,000 people, but need more typically to be cities of
250,000 to a million people, themselves with internal green
wedges and networks.
This is the vision put forth by the father
of the garden city movement, Ebenezar Howard, and also Kevin
Lynch, another famous urbanist: a high density polycentric
urban structure with high speed transport networks.
By closer living, we may be able to reduce,
or even remove, the need for concreting 20-25% of the urban
fabric with roads and the noise, pollution and noxious gasses
that are emitted. If we only paved 10% of public space - the
other 10% could be linear parks and landscaping, possibly
edible landscapes, that we would move along. We could have
250,000 people living tightly together, quietly, with the
sound of birdsong, rather than traffic.
The green city is a group of village cells
in areas covering a 'walkable' 500m x 800m, roughly. Between
these cells are the green wedges and networks of sports fields,
lakes, windmills, wetlands and reservoirs for water polishing,
urban cooling and recreation, trees and forest with wildlife
corridors and links. These wedges, that could be some 100m
to 500m wide, contain the high speed transit links - trains,
not cars - that move between village cells such that there
is no limit on mobility. Could it be a car-free city? Possibly.
But, rainwater collection with individual or communal storage
facilities would be vital.
Idealist urban visions often have failed,
such as in Chandigarh and Brasilia, because of the lack of
ability to create vibrant urban spaces and places - and it
is the success of the social and spatio-physical fabric that
will make the place desirable and enduring. We need nooks
and crannies, squares and alleys - in a tropical, subtropical
or temperate response as appropriate.
The development may begin as 1-3storeys, but as demand for
land increases, the framework should be able to accommodate
20+ storey buildings, wherein an urban form like the cities
of South Korea being to emerge: compact, with all surrounding
forests in tact, and high density. Thus, a good street-block
framework is a critical component in long-term re/development.
Fundamentally, to get a green city requires political leadership
to force densification and create restriction at the edges,
and to keep green wedges and ecological functioning. |