WAY TOWARDS AN EFFICIENT CITY
INDEX
•
Introduction-Concept
•
Excessive growth
•
Urban Ecosystems
•
Efficient city
•
Superblocks, Barcelona. (BMW initiative award 2011)
•
Conclusion
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INTRODUCTION-CONCEPT
Ecology is the branch of biological sciences dealing with the interactions
between living creatures and their environment (chemical and physical factors).
Ecology is a multidisciplinary science which is closely related to Biology,
Climatology, Chemistry, Biophysics, Engineering, Mechanics, Architecture,
Geology, Physics and Mathematics.
Concretely, our theme to study is urban ecology. Nowadays, it is an
important topic, due to cities are an ecosystem and we should understand its
operation and it is essential to design future strategies and to watch its
development.
The ecology provides to the urban phenomenon a metabolic point of
view, and it allows to know energy flows and materials in the city. This way to
understand the city is been introduced in lots of management strategies of local
administrations.
The functional approach of the urban ecosystem is completed taking into
account the negative consequences of the interaction between the population
and the natural or seminatural resources, besides the effects of the nature in
people's lives. If these effects are beneficial, they are services.
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EXCESSIVE GROWTH
Urbanization is one of the most important and fast processes done by
men on Earth, and it is one of the most significant causes of the climate change.
Due to this fact, it is important to understand this process to try to lead it in a
reasonable way and to correct the consequences of the urban expansion.
Dubai 1990/2010
In most of the world, cities grow in a dizzying way. This is a population
growth and territorial expansion. In the early twentieth century, there were 1500
million of people, and a century later 7000 millions. We must also note the
tendency to live in cities. Today, 60% of the humanity lives in cities, and in
2050, we expect that 76% will live in cities. Regarding the world population,
cities consume two-thirds of urban energy and emit 70% of CO2. 1
The urban expansion pattern provokes a peculiar problem. Cities do not
grow in a concentric way, they do along transport routes, from small cores
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dispersed over the territory and they are spreading... This process means a
enormous fragmentation of natural or seminatural systems, and a deterioration
of its potential.
This dynamism of cities and its impact in our planet make urgent to
increase our knowledge about the urban system.
URBAN ECOSYSTEMS
In this paper, we understand ecology like a study of urban ecosystems,
without dealing the ecology of individual organisms which have their habitat in
an urban environment. Both meanings are used by ecologists and they are
equally legitimate but their significances are different.
Cities are ecosystems, but this fact was not recognized until the
seventies, and P. Duvigneaud and S. Denaeyer-De Semt did the first
publications about this topic.2 However, urban ecosystems pose many
theoretical and practical challenges. Natural ecosystem are very complicated,
but, urban ones are more heterogeneous, due to lots of their aspects are
relationated with activities and decisions about politics, economy, society or
culture.
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EFFICIENT CITY
We consume in seconds the energy that nature
has taken millions of years to produce, we spend more
than we produce and demand is growing, so saving
and energy efficiency is the major challenge of the
cities of twenty-first century.
For thousands of years, cities are created in
places where people settle permanently. In a world of limited resources, growth
cannot be infinite, so we are forced to rethink the city model of this century. We
must think about a city as a whole and the parts which form it: territory,
biological capacities of the city, how much energy we spend, how we move,
waste, water and communications.
A city is composed of public and private spaces, walkways and transition,
thoroughfares, parks. Buildings and sustainable land occupation in 2020, would
reduce 25% energy consumption, and even 45% of emissions of greenhouse
gases. 3
Due to these reasons, municipalities around the world apply creative
solutions to reduce energy consumption, water spending, waste and emissions,
while facilitating the movement of people. These solutions can be classified into:
mobility, energy saving, energy obtaining, waste.
Measures to facilitate mobility:
-Intelligent Parking: digital parking meters notify mobile phones and
navigation applications that there is a free parking space, which lightens the
traffic created by the search for parking. (San Francisco)
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-Underground parking: underground garages next to the destinations
prevent the occupation of the area by cars. (Paris)
-The cost of congestion: to apply higher rates to drivers who travel in
clustered areas, tends to soften the traffic. (Stockholm, Singapore)
-Subterranean transport: commuter trains, tube and major roads run
through large underground tunnels. The surface is free to you walking or
cycling, non-polluting. (Portland, Oregon)
-Support and bike lanes: a large bike lanes and places to save them,
encourage people to use them, and it also promotes the physical exercise.
(Minneapolis)
-Hybrid taxis: the conversion of much of the taxi fleet to hybrid vehicles
reduces air pollution and emissions of greenhouse gases. (San Francisco, New
York)
Measures to obtain energy:
-Wave energy: cylinders embedded by hinges in the seabed are thrusted
by waves and they activate turbines to generate electricity. (Orkney, Scotland)
-Underwater turbines: turbines settled on the seabed revolve by the
action of daily tides and they generate electricity. (New York)
-Solar Water Heating: hot water for domestic use is not obtained from
boilers, but deposits exposed to sunlight on roofs. (Rizhao, China).
-Solar panels: the south-facing facades are covered with photovoltaic
panels which generate electricity.
-Solar energy: electricity is generated by panels, not by power plants.
They also shade the roof, and lower cooling requirements of the building.
Measures to save energy:
-High performance windows: special insulation windows quadruple the
thermal efficiency of the dual pane and they can be made from existing window
glass. (Empire State Building, New York)
-Sequestering carbon concrete: greenhouse gases could be reduced by
using locally manufactured concrete from carbon dioxide emitted by power
plants. (in development)
-Vertical farming: growing food would moderate the use of fertilizers and
fresh water, it would reduce the transport and recycles gray water thrown out
by treatment plants. (in development)
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-Green roofs: vegetation on the roof
insulates the house against heat and cold,
and also absorbs rainwater. (Chicago)
-White roofs: roofs painted white reflect
heat, reduce the cost of building cooling and
prevent overheating of the city. (Washington)
The
-Sustainable
neighborhoods:
construction according to organic standards,
certification, or Leadership in Energy and Environmental Design (LEED), saves
energy or materials and reduces emissions. (Rockville, Maryland)
-Fee for runoff water: to charge taxes to property owners for the value of
the number of runoff discharged during storms promotes reforms to reduce the
volume of wastewater treatment plants. (Finland)
-Irrigation control with satellite: satellite monitoring of irrigation systems in
parks and lawns reduces water consumption and energy needed to pump. (Los
Angeles)
-Machine with low-flow: to install toilets and showers in homes which
economize water, save millions of liters per year. (Austin, Texas)
Measures to manage waste:
-Selective collection: stores and housings must separate waste: organic
waste, recyclables and rest. The tax collection would be reduced to people
which generate less waste. (San Francisco)
-Incineration of sewage sludge: solid waste removed from wastewater in
sewage treatment plants are burned to produce electricity (Nashville, Buffalo)
SUPERBLOCKS, BARCELONA. (BMW INITIATIVE AWARD
2011)
After discussing the different solutions which can be carried out in cities
to become ever more efficient, I would add the BMW Initiative Award 2011. This
award consists of a commitment to society, and in favor of values such as
creativity, innovation and sustainability.
BMW Initiative Award 2011 recognizes results of Implementation Plan of
two Superblocks in Gràcia district, in Barcelona, which has improved the
functionality and urban quality of this area significantly. This project has been a
pioneer in applying the conceptual, instrumental and organizational SmartCity, a
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new model of compact and complex city.
Salvador Rueda, creator of Superblocks
Public space is the main heritage that our cities have and return it to
citizens is the basis of a sustainable city. Under this principle the concept of
SmartCity (a city that presents a new energy management model based on
sustainable and efficient development, thanks to new technologies and with the
direct participation of citizens), articulates the project of the Urban Ecology
Agency of Barcelona.
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After more than two years of work, the implementation of two Superblocks (new
urban cells of 400 × 400 m and it includes several blocks inside) in Gràcia
district has given rise to a new mobility model, a new management of public
space and accessibility to it. With this first sample, the Urban Ecology Agency of
Barcelona aims to redefine a new model of city in Barcelona, making it more
accessible for pedestrians, which returns to its hegemony in the public space
and encouraging the use of more sustainable transport.
Superblocks join urban planning and mobility planning to limit the
movement of private vehicles on public space. With the implementation of
Superblocks fits each space to different uses. A new distribution network
includes the passing vehicles and another local network, composed of interior
streets where circulating only neighbors, urban services, emergency services
and taxis, releases the public area of passing traffic and recovers it for other
uses, improving qualitative and environmentally the public space and mobility.
With Superblocks, proportions between the space occupied by vehicles
and other uses are reversed. In the case of Gràcia district, proportions between
driveway and sidewalk were divided by 54% and 46% respectively. With the
application of Superblocks, the percentage of roadway is reduced 25% and
sidewalk increases 75%.
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CONCLUSION
Urban Ecology, as a natural science, is a young discipline which was
developed in recent decades from a branch of biology to an interdisciplinary
field of application in the local and regional planning.
It studies the impact of human activities on the environment and finding
solutions that help improve or preserve the environment for mutual benefit.
Therefore, according to proposals for improving the quality of urban
environments and to direct its operation to a better use of resources, it is
important to include green elements in urban planning strategies not only for its
value in the urban landscape but also for its functionality as a structural element
in shaping a city.
It is necessary to establish a new urban paradigm, which could reveal
itself as an integrated view of the city, its social, environmental and economic
contents, where satisfaction of urban needs is conducted in a consistent way
with the reduction of energy and environmental impact through the containment
of indiscriminate growth, recycling and upgrading of the existing city, the sharp
increase in urban eco-efficiency and the multiplication of the logic and
renewable systems.
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BIBLIOGRAPHY
Magazine Investigación y Ciencia, November 2011
Madre Tierra y Naturaleza (PhotoEspaña 2006)
http://www.biocab.org
http://www.bcnecologia.net
http://www.diariodesign.com
http://www.plataformaurbana.cl
http://www.ecologiaycampo.com
1. Information of http://www.unhabitat.org/categories.asp?catid=9
2. Cuivre et végétation au Katanga , 1963. Publishing company: CEMUBAC.
Paul Auguste Duvigneaud and Simone Denaeyer-De Smet.
3. Information of OSE (http://www.sostenibilidad-es.org/)
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