Hello in the previous weeks, you have learned how t o handle a variety
of challenges for infrastructure development, and you have seen how information and telecommunication
technologies shape future infrastructure development.
However, we have not focused yet on the context of
infrastructure development.
The world in which we develop the next generation of infrastructures is a world that is being
urbanized at an unprecedented pace.
Since 2008, more than half of the current 7 billion world
population is living in cities.
By 2050, more than two thirds of the world population
will be urban.
The latest UN estimates of world population growth point out that by 2100,
planet earth may be inhabited by 12 billion people.
On the basis of the current urbanization trend it seems a safe bet that most of them will
be living in cities.
So what is it that makes cities so attractive?
Has infrastructure something to do with it?
Is it good or bad news that cities are growing, while rural areas are being depopulated?
And what challenges do cities pose for infrastructure development,
especially taking into account that the number of extremely large cities is increasing?
Let us have a look at the pattern of urbanization worldwide.
Looking at the percentage of the population of different countries that actually lives
in cities, we see widely diverging figures.
In Argentina , 92% of the population is urban,
and more than 35% of the population lives in the largest city,
Buenos Aires, where more than 13.6 million people live.
We see a similar pattern in Japan, where 91% of the population is urban,
with 32% of the population living in Tokyo, a megacity of more than 37 million people,
in fact, the largest metropolitan area in the world.
In 2012, according to urban area population and density update by geography.
26 urban areas in the world qualified as megacities.
So what defines an urban area, a city or a metropolitan area?
According to New Geography, an urban area is an area of continuous urban
development within a metropolitan area.
An urban area or an urban agglomeration is the physical expression of a city – it is
what you can see and touch: a concentration of built environment – homes,
offices, industrial facilities,
all types of infrastructure – which is clearly visible in a satellite view,
especially at night.
It is the physical environment where large numbers of people live and work in close proximity
to each other.
The economic and functional expression of a city is the metropolitan area.
A metropolitan area is defined as an economic region:
the combination of urban, sub-urban and rural areas which together comprise
the labor market of the region.
In wikipedia you will see a metropolitan area defined as:
a region consisting of a densely populated urban core and its
less densely populated surrounding territories, sharing industry,
infrastructure and housing.
Metropolitan areas include one or more urban areas,
as well as satellite cities, towns and intervening rural areas that are
socio-economically tied to the urban core – as typically is measured by commuting patterns.
Hence, a metropolitan area usually comprises multiple
jurisdictions: municipalities,
counties, districts,
even states and nations.
Changing social, economic and political institutions have made
metropolitan areas increasingly relevant as socio-economic entities and identities.
How come that vast countries like Australia or Argentina are among the most urbanized
countries in the world?
Australia is largely empty , as 89% of the people huddle together in large
urban agglomerations on its coasts.
Why do 92% of the people in Argentina prefer to live in cities – with 35% of its population
concentrated in Buenos Aires?
Apparently, cities are an attractive habitat for the human species.
Without going into psychological explanations, I think it is clear that for most people,
the opportunities that cities offer for social interaction,
jobs, education,
cultural activities and so on, outweigh the disadvantages of living in cities.
Indeed, the work of Geoffrey West,
Louis Bettencourt and others at the Santa Fe institute,
shows that the productivity of cities increases with the size of the urban population.
The larger the city, the more innovation and wealth it produces per capita.
But the productivity does not increase linearly with the size of the population,
it increases in a supralinear fashion : doubling the size of the city systematically
increases wealth and income with a scaling factor of 1.15.
In other words, doubling the size of the city leads to more
than double the productivity of the city, as we see an increase of 15% in,
for example, wages and number of patents per capita.
The city is an intriguing organism: whereas biological organisms scale sublinearly
(their metabolism grows slower as the size of the organism increases),
cities exhibit a opposite behaviour.
Their metabolic rate increases supralinearly with increasing size of the urban system.
Looking back into history, we see that natural infrastructure dictated
the places where successful human settlement occurred.
The rivers Euphrates, Tigris and Nile enabled civilization and with
it, cities,
to emerge in Mesopotamia and Egypt, around 6000 BC.
Cities allow for a smart division of tasks and hence,
economic specialization, which increases productivity and generates
more wealth for all to share.
Already then, man interfered with manmade infrastructure
for a variety of essential functions, such as water storage,
flood control and irrigation.
Many of the techniques developed then are still in use today.
People’s choice to live in cities has always been a trade-off between opportunity and risk:
cities offered protection against enemies, but also risk,
for example the risk of contagious diseases.
In the past, many cities were situated in such a way that
natural infrastructure posed a barrier to invading enemy forces.
As example, Machu Picchu in Peru.
As we can see today, with more and more megacities situated in
flood-prone coastal zones, the location of cities is generally a trade-off
between accessibility and safety.
Coastal zones and river deltas offer premium shipping and trading opportunities.
At the same time, they are vulnerable to flooding.
One of the most extreme examples of such risks is the Western part of the Netherlands,
which is situated below sea level.
Dike ring 14 in this area, one of a total of 53 dike rings protecting
the Netherlands from flooding, protects a region where 3.5 million people
generate approximately 65% of the Dutch GDP.
Urbanization patterns in the world differ widely.
While Japan and Europe show very low urbanization rates,
below 1%, the annual increase in urban population is
above 1% in most parts of the world, and a staggering 2.3% and 2.4% in China and
India, respectively.
In Europe , megacities are the exception rather than the
rule.
Only Paris is a true megacity.
In Germany and the Netherlands, with 74% and 83% of the population living
in urban agglomerations, we see that the population is distributed
over a large number of relatively small cities.
In Japan and Argentina, the urban population is much more concentrated
in fewer, much larger cities.
By far the largest number of megacities is found in Asia.
16 of today’s 26 megacities (with a population of over 10 million) are located in Asia.
We see staggering population densities, up to 30,900 people/km2 in Mumbai,
India and 44,400 people/km2 in Dhaka, Bangladesh.
Looking at the patterns, we are tempted to speculate that the growth
of megacities is an auto-catalytic process: as the opportunities increase supralinearly
with the size of the city, the city becomes a stronger magnet for people
and talent as it grows.
Compare the NASA satellite images of the Pearl River Delta,
the first one of October 1979 where you will find Guangzhou,
the Guangdong state capital, as a very compact city.
Since then, Shenzhen started to develop,
as the first Special Economic Zone in China implemented by Deng Xiao Ping.
On the NASA picture of January 2003 you can see how much difference that made.
The Pearl River Delta is now home to approximately 45 million people,
and the previously disparate urban agglomerations are now merging into a region-wide metropolis
which is, moreover,
strongly interconnected with Hong Kong.
Is the current trend towards urbanization good or bad news for food ,
energy and water security?
Is it good or bad news for the environment?
What are its needs in terms of infrastructure development?
How can infrastructure cater for ‘Better city,
better life’ – the slogan of the Shanghai World expo in 2010?
Is Infrastructure the key to the factor 8 efficiency improvement and productivity question?
We will try to find some answers in the next module.
Stay with us and thank you very much.