Urban metabolism of Beijing (1)
University of Toronto
Faculty of Applied Science and Engineering
CIV282 & CIV220
Urban Metabolism of Beijing
(Final Report)
Tutorial 0102
Danhui Li
999086956
Due: October 5, 2012
Signature:
This report is entirely done by Danhui Li, and all references are cited.
1. Introduction
Beijing, the capital city of China, is one of the most densely populated cities in the world with
more than 19 million people (in 2010) living in it. [1] It is located at the North-East corner of
China at 39°N, 116°E and occupied a total area of 16807.8 km2. [2] Density of this city can be
simply calculated as about 1200 people/km2. Beijing has been the capital city of China since 1153
and many people still try to move in this city each year. Beijing is divided by six ring roads from
inner to the outer part and population is concentrated inside the forth ring road area. [Figure 1]
A great amount of resources are input to and output from this city every day, thus, the research of
urban metabolism is important to record and analyze these resources. Urban metabolism is the
study of the import and export resources in a city. It deals with not only human activities but also
environmental processes.
In this report, several main metabolism elements of Beijing will be analyzed to find a more
sustainable way to develop the city. Also, a diagram will be used to indicate the exact input and
output resources on Beijing. Last but not the least, analogy between metabolism of a city and a
natural entity will be discussed at the end.
2. Diagram of Urban Metabolism in Beijing
In this section, key metabolism elements which will be talked later in this report are listed.
Input (per person/year) (2008)
Output (per person/year) (2008)
Electronic Energy [2]
724273.68 GJ
Waste water [4]
36.7 tones
Clean Water [3]
126.3 tones
SO2 [6]
63kg
Sunlight [2]
3784.21 GJ
CO2 [7]
8.42 tones
Rainfall [4]
111.05 tones
Solid waste [8]
2.17 tones
Dust [5]
2.63 kg
Recycled Water [4]
15.73 tones
Coal [2]
0.889 tones
NOx [6]
0.101 tones
Wood [2]
0.00657 m3
Oil [2]
0.438 tones
2.1 Diagram
3. Analysis and Suggestions of Major Metabolism Elements
Actually, Beijing is a city has a scarce of resources. Compare to its population, only small amount
of water, electricity energy, and building materials can be provided by itself. Therefore, it is
significantly important to find a way to use the resources efficiently. Here are some major
metabolism elements in Beijing that should be analyzed and improved.
2.1 Water Resources
2.1.1 Problem
Beijing is located in a warm temperature zone and has a continental climate. There are
rainfalls in the summer times but for all the other months, this city is quite dry.
Table 1: Water resources (2000-2009)
Water resources [3]
Water required [3]
Recycled Water [4]
Waste water discharge
(tones/person/year)
(tones/person/year)
(Tones/person/year)
(tones/person/year) [4]
126.3
184.2
15.73
36.7
By analyzing the table above, it’s easy to see that Beijing need water import to keep things
working. Also, the low amount of waste water discharge and recycled water may due to the
scarce of water resource.
2.1.2 Suggestions
Transport fresh water from other cities to Beijing. By doing so, problem of water scarcity
in Beijing can be solved completely; however, this may cost a lot of time and money
since 1.1×109 tones of water will be imported each year. [3]
Increase the efficiency of water re-treatment system and reuse water in the daily life. In
Beijing, there are 44 water treatment facilities and 30% of the wastewater can be treated
nowadays. [9] More of these facilities should be built so that the ratio of water
retreatment can be raised.
Use artificial rain to increase the rainfall amount in Beijing from March to May. This can
also decrease the air pollution level since rainfall can rain off the airborne contaminant.
2.2 Air pollution
2.3.1 Problem
Air pollution is one of the most well-known environmental problems in Beijing. Airborne
contaminant cannot be rained off since the city is quite dry in most time of the year. One
problem of the air in Beijing is the dust storms from North-West part of China. There are
several deserts located at this place and strong winds occur in a spring monsoon to bring
desert storm in March and April every year. Moreover, there isn’t any large mountain or forest
between the city of Beijing and these deserts so that dust can be blown to Beijing directly. [10]
The dust storms significantly decrease the quality of air in Beijing in spring.
Also, another main part of the air pollution in Beijing is the exhaust air emitted by vehicles.
There is a high density of cars in this city because of the large population. According to
research, there are more than 3 million cars in the city and a large amount of exhaust air such
as CO2 and SO2 are emitted by them. [11]
2.3.2 Suggestions
More plants should be grown inside the forth ring road to absorb the exhaust air from
vehicles.
As what stated before, artificial rain can be used to rain off airborne contaminants
periodically. Artificial rain can give benefit to both the water resource and the air quality
in Beijing.
Restrict the use of vehicles and encourage citizens to use the public transportations. By
doing so, not only the emission of exhaust air but also the use of gasoline resource can be
reduced. This is what the Beijing government is doing now and it reduces 20% of the
exhaust air. [12]
Build satellite cities around Beijing so that population in the downtown area can be
reduced. Quality of air will be improved if there are less people.
2.3 Canopy Cover
2.2.1 Problem
According to the research, 44.4% of ground in Beijing is covered by the plants. However,
most of them are grass and they concentrate in several big parks. [8] Only small amount of
plants distributed inside the forth ring road area. It is difficult to plant too many plants in this
city because of the limit amount of water. Also, at the North-West corner, Beijing is scarce of
trees to prevent the dust storm which is a big problem that should be improved.
Furthermore, another plant problem in Beijing is that some of the canopy used in this city can
only sustain for about 2 years. Every year in fall, it is easy to see trucks coming around to dig
out the old lawns on the sidewalk and replaced by new ones.
Table 2: Land area, tree cover and canopy cover inside 4th ring of Beijing [13]
Land area
Tree number
Tree density
Canopy cover
(hectare)
(thousand)
(number/hectare)
(%)
14304
1371
96
12
By comparing the data of canopy cover in this table and the 44.4% of plant cover all over the
city, it’s easy to see how canopy in Beijing are concentrated outside of the 4th ring.
2.2.2 Suggestions
Grow more plants in the North-West corner of Beijing. This can significantly reduce the
damage from the dust storm.
Build some small parks inside the 4th ring road area can help absorb CO2 generated by
people. Growing plant is a cost efficient way to improve the quality of air. This can also
reduce the amount of wood import.
Type of seed for the lawn grass should be reconsidered and the lawn should be taken care
of to increase its lifetime. This can reduce the inefficient money and energy used for
replacing the lawn and make the city works more sustainable.
2.4 Solid waste
2.4.1 Problem
The population and economical growth cause the rapid generation of solid waste in Beijing.
In 2006, 4.134 million tons of solid waste was generated but only 8% of them were
well-treated by incineration. [8][14] Most of the solid wastes were treated by landfill which
occupied the ground and created pollution. Air pollutions are created by the incineration and
to treat solid waste by landfill may pollute the water.
2.4.2 Suggestions
New destructor plant should be build to increase the amount of solid waste treated by
incineration to at least 30% since it is more environmental friendly and required less area
of ground. Also, the heat energy released by combustion can be used to instead the
imported electronic energy. This increases the efficiency of Beijing’s urban metabolism.
These four aspects of urban metabolism in Beijing are highly related since the improvement of
one can affect the others. For example, increase the water resource and decrease the land used for
landfill solid waste in Beijing can provide a better environment for the canopy to live, and the
additional canopy can reduce the air pollution in the city. By applying some or all these
suggestions listed above, Beijing can have a more circular metabolism and better environment.
3
Critique of the Urban Metabolism Analogy
Urban metabolism analogy is a useful tool to study and understand how an urban city works with
all its imported resources and energy and exported waste products. By comparing urban
metabolism, metabolism in the natural organism, and the ecosystem, it’s easy to see that the
analogy between urban metabolism and metabolism in organism is stronger since there isn’t a
sense of digestion in the ecosystem. The process of input energy and output waste in urban
metabolism is similar to the process of input food and output of waste in a natural organism.
However, even though both of them are transforming energy into waste, there are still something
different. Only a small part of the waste in the urban metabolism can be recycled or reused again
but in the world of organism, the waste from one species can be useful to another species. There
is rarely any waste in natural.
The analogy of metabolism gives a clear overview to the city and helps to understand not only
the import and export resources in it, but also how they are used. Learning urban metabolism can
help us to understand how urban impact and being impacted by the environment. On the other
hand, looking at the city in an analogy way may hide the culture aspect of the city. For example,
by analyzing the urban metabolism in Beijing, replace the old houses and narrow roads inside the
second ring road by modern buildings and wide streets can be considered as a good idea to
increase the population affordability of the city. However, all these houses and roads are built
hundreds years ago; they are part of the culture in Beijing and should be protected. This weakness
of the analogy can be overcome by adding the culture factor as a consideration part during the
analyzing.
Appendix:
[Figure 1]
(Ring Roads in Beijing)
Since the first ring is the Forbidden City, the inner ring road on this picture is the second ring
road.
http://chicvoyagetravel.com/chicvoyage-in-beijing/
References:
[1] “Beijing” [Online] Accessed Sept.27, 2012,
Available: http://en.wikipedia.org/wiki/Beijing#Climate
[2] Zhang, Y., et al., Emergy analysis of the urban metabolism of Beijing. Ecol. Model. (2010),
doi:10.1016/j.ecolmodel.2010.09.017
[3] News, “Beijing has a scarae of water resources”, Accessed September 28, 2012, [Online]
Available: http://news.xinhuanet.com/politics/2011-08/12/c_121849553.htm
[4] Report, “Water resources in Beijing”,[Online], Accessed: October 5, 2012,
Available: http://www.bjwater.gov.cn/tabid/207/Default.aspx
[5] Article, “Beijing Air Quality”, [Online], Accessed September 28, 2012,
Available: http://www.beijing-travels.com/beijing_guide/overview/air_quality.html
[6] Yu Lei, Qiang Zhang, Chris Nielsen, Kebin H, “An inventory of primary air pollutants and
CO2 emissions from cement production in China, 1990e2020”,[Online], Accessed September 28,
2012, Available: http://mic.greenresource.cn/static/publications/lei_ae_2011.pdf
[7] Jimin Zhao, “Climate Change Mitigation in Beijing, China”, [Online], Accessed: October 5,
2012, Available:
http://www.unhabitat.org/downloads/docs/GRHS2011/GRHS2011CaseStudyChapter05Beijing.pdf
[8] Beijing Statics, “Resources, Energy, and Environment (2000~2009)”, Accessed: September
27, 2012, [Online] Available: http://www.bjstats.gov.cn/sjtjr/szbj/201009/t20100913_184701.htm
[9] Anjun Pan, “Water Management in Beijing”, [Online], Accessed: October 2, 2012, Available:
http://www.un.org/esa/sustdev/sdissues/water/workshop_asia/presentations/pan.pdf
[10] Jinghua Guo, Kenneth A. Rahn, Guoshun Zhuan, “A mechanism for the increase of pollution
elements in dust storms in Beijing” [Online], Accessed: October 5, 2012, Available:
http://environment.fudan.edu.cn/CACS/papers/A%20mechanism%20for%20the%20increase%20of%20polluti
on%20elements%20in%20dust%20storms%20in%20Beijing.pdf
[11] Article,” Beijing’s Vehicle Population Reached 3,765,000”, [Online], Accessed: October 5,
2012, Available: http://www.bjjtgl.gov.cn/publish/portal1/tab165/info13357.htm
[12] Article, Xin Dingding, “Beijing car restrictions to continue”, [Online], Accessed: September
28, 2012, Available: http://www.chinadaily.com.cn/bizchina/2009-04/06/content_7651378.htm
[13] Jun Yang, Joe McBride, Jinxing Zhou, Zhenyuan Sun, “The urban forest in Beijing and its
role in air pollution reductio”, Accessed September 27, 2012. [Online]
Available: http://www.fs.fed.us/ccrc/topics/urban-forests/docs/urban%20forest%20Beijing.pdf
[14] Li ZS, Yang L, Qu XY, Sui YM., “Municipal solid waste management in Beijing City”,
[Online], Accessed September 28, 2012, Available:
http://www.ncbi.nlm.nih.gov/pubmed/19375298
Faculty of Applied Science and Engineering
CIV282 & CIV220
Urban Metabolism of Beijing
(Final Report)
Tutorial 0102
Danhui Li
999086956
Due: October 5, 2012
Signature:
This report is entirely done by Danhui Li, and all references are cited.
1. Introduction
Beijing, the capital city of China, is one of the most densely populated cities in the world with
more than 19 million people (in 2010) living in it. [1] It is located at the North-East corner of
China at 39°N, 116°E and occupied a total area of 16807.8 km2. [2] Density of this city can be
simply calculated as about 1200 people/km2. Beijing has been the capital city of China since 1153
and many people still try to move in this city each year. Beijing is divided by six ring roads from
inner to the outer part and population is concentrated inside the forth ring road area. [Figure 1]
A great amount of resources are input to and output from this city every day, thus, the research of
urban metabolism is important to record and analyze these resources. Urban metabolism is the
study of the import and export resources in a city. It deals with not only human activities but also
environmental processes.
In this report, several main metabolism elements of Beijing will be analyzed to find a more
sustainable way to develop the city. Also, a diagram will be used to indicate the exact input and
output resources on Beijing. Last but not the least, analogy between metabolism of a city and a
natural entity will be discussed at the end.
2. Diagram of Urban Metabolism in Beijing
In this section, key metabolism elements which will be talked later in this report are listed.
Input (per person/year) (2008)
Output (per person/year) (2008)
Electronic Energy [2]
724273.68 GJ
Waste water [4]
36.7 tones
Clean Water [3]
126.3 tones
SO2 [6]
63kg
Sunlight [2]
3784.21 GJ
CO2 [7]
8.42 tones
Rainfall [4]
111.05 tones
Solid waste [8]
2.17 tones
Dust [5]
2.63 kg
Recycled Water [4]
15.73 tones
Coal [2]
0.889 tones
NOx [6]
0.101 tones
Wood [2]
0.00657 m3
Oil [2]
0.438 tones
2.1 Diagram
3. Analysis and Suggestions of Major Metabolism Elements
Actually, Beijing is a city has a scarce of resources. Compare to its population, only small amount
of water, electricity energy, and building materials can be provided by itself. Therefore, it is
significantly important to find a way to use the resources efficiently. Here are some major
metabolism elements in Beijing that should be analyzed and improved.
2.1 Water Resources
2.1.1 Problem
Beijing is located in a warm temperature zone and has a continental climate. There are
rainfalls in the summer times but for all the other months, this city is quite dry.
Table 1: Water resources (2000-2009)
Water resources [3]
Water required [3]
Recycled Water [4]
Waste water discharge
(tones/person/year)
(tones/person/year)
(Tones/person/year)
(tones/person/year) [4]
126.3
184.2
15.73
36.7
By analyzing the table above, it’s easy to see that Beijing need water import to keep things
working. Also, the low amount of waste water discharge and recycled water may due to the
scarce of water resource.
2.1.2 Suggestions
Transport fresh water from other cities to Beijing. By doing so, problem of water scarcity
in Beijing can be solved completely; however, this may cost a lot of time and money
since 1.1×109 tones of water will be imported each year. [3]
Increase the efficiency of water re-treatment system and reuse water in the daily life. In
Beijing, there are 44 water treatment facilities and 30% of the wastewater can be treated
nowadays. [9] More of these facilities should be built so that the ratio of water
retreatment can be raised.
Use artificial rain to increase the rainfall amount in Beijing from March to May. This can
also decrease the air pollution level since rainfall can rain off the airborne contaminant.
2.2 Air pollution
2.3.1 Problem
Air pollution is one of the most well-known environmental problems in Beijing. Airborne
contaminant cannot be rained off since the city is quite dry in most time of the year. One
problem of the air in Beijing is the dust storms from North-West part of China. There are
several deserts located at this place and strong winds occur in a spring monsoon to bring
desert storm in March and April every year. Moreover, there isn’t any large mountain or forest
between the city of Beijing and these deserts so that dust can be blown to Beijing directly. [10]
The dust storms significantly decrease the quality of air in Beijing in spring.
Also, another main part of the air pollution in Beijing is the exhaust air emitted by vehicles.
There is a high density of cars in this city because of the large population. According to
research, there are more than 3 million cars in the city and a large amount of exhaust air such
as CO2 and SO2 are emitted by them. [11]
2.3.2 Suggestions
More plants should be grown inside the forth ring road to absorb the exhaust air from
vehicles.
As what stated before, artificial rain can be used to rain off airborne contaminants
periodically. Artificial rain can give benefit to both the water resource and the air quality
in Beijing.
Restrict the use of vehicles and encourage citizens to use the public transportations. By
doing so, not only the emission of exhaust air but also the use of gasoline resource can be
reduced. This is what the Beijing government is doing now and it reduces 20% of the
exhaust air. [12]
Build satellite cities around Beijing so that population in the downtown area can be
reduced. Quality of air will be improved if there are less people.
2.3 Canopy Cover
2.2.1 Problem
According to the research, 44.4% of ground in Beijing is covered by the plants. However,
most of them are grass and they concentrate in several big parks. [8] Only small amount of
plants distributed inside the forth ring road area. It is difficult to plant too many plants in this
city because of the limit amount of water. Also, at the North-West corner, Beijing is scarce of
trees to prevent the dust storm which is a big problem that should be improved.
Furthermore, another plant problem in Beijing is that some of the canopy used in this city can
only sustain for about 2 years. Every year in fall, it is easy to see trucks coming around to dig
out the old lawns on the sidewalk and replaced by new ones.
Table 2: Land area, tree cover and canopy cover inside 4th ring of Beijing [13]
Land area
Tree number
Tree density
Canopy cover
(hectare)
(thousand)
(number/hectare)
(%)
14304
1371
96
12
By comparing the data of canopy cover in this table and the 44.4% of plant cover all over the
city, it’s easy to see how canopy in Beijing are concentrated outside of the 4th ring.
2.2.2 Suggestions
Grow more plants in the North-West corner of Beijing. This can significantly reduce the
damage from the dust storm.
Build some small parks inside the 4th ring road area can help absorb CO2 generated by
people. Growing plant is a cost efficient way to improve the quality of air. This can also
reduce the amount of wood import.
Type of seed for the lawn grass should be reconsidered and the lawn should be taken care
of to increase its lifetime. This can reduce the inefficient money and energy used for
replacing the lawn and make the city works more sustainable.
2.4 Solid waste
2.4.1 Problem
The population and economical growth cause the rapid generation of solid waste in Beijing.
In 2006, 4.134 million tons of solid waste was generated but only 8% of them were
well-treated by incineration. [8][14] Most of the solid wastes were treated by landfill which
occupied the ground and created pollution. Air pollutions are created by the incineration and
to treat solid waste by landfill may pollute the water.
2.4.2 Suggestions
New destructor plant should be build to increase the amount of solid waste treated by
incineration to at least 30% since it is more environmental friendly and required less area
of ground. Also, the heat energy released by combustion can be used to instead the
imported electronic energy. This increases the efficiency of Beijing’s urban metabolism.
These four aspects of urban metabolism in Beijing are highly related since the improvement of
one can affect the others. For example, increase the water resource and decrease the land used for
landfill solid waste in Beijing can provide a better environment for the canopy to live, and the
additional canopy can reduce the air pollution in the city. By applying some or all these
suggestions listed above, Beijing can have a more circular metabolism and better environment.
3
Critique of the Urban Metabolism Analogy
Urban metabolism analogy is a useful tool to study and understand how an urban city works with
all its imported resources and energy and exported waste products. By comparing urban
metabolism, metabolism in the natural organism, and the ecosystem, it’s easy to see that the
analogy between urban metabolism and metabolism in organism is stronger since there isn’t a
sense of digestion in the ecosystem. The process of input energy and output waste in urban
metabolism is similar to the process of input food and output of waste in a natural organism.
However, even though both of them are transforming energy into waste, there are still something
different. Only a small part of the waste in the urban metabolism can be recycled or reused again
but in the world of organism, the waste from one species can be useful to another species. There
is rarely any waste in natural.
The analogy of metabolism gives a clear overview to the city and helps to understand not only
the import and export resources in it, but also how they are used. Learning urban metabolism can
help us to understand how urban impact and being impacted by the environment. On the other
hand, looking at the city in an analogy way may hide the culture aspect of the city. For example,
by analyzing the urban metabolism in Beijing, replace the old houses and narrow roads inside the
second ring road by modern buildings and wide streets can be considered as a good idea to
increase the population affordability of the city. However, all these houses and roads are built
hundreds years ago; they are part of the culture in Beijing and should be protected. This weakness
of the analogy can be overcome by adding the culture factor as a consideration part during the
analyzing.
Appendix:
[Figure 1]
(Ring Roads in Beijing)
Since the first ring is the Forbidden City, the inner ring road on this picture is the second ring
road.
http://chicvoyagetravel.com/chicvoyage-in-beijing/
References:
[1] “Beijing” [Online] Accessed Sept.27, 2012,
Available: http://en.wikipedia.org/wiki/Beijing#Climate
[2] Zhang, Y., et al., Emergy analysis of the urban metabolism of Beijing. Ecol. Model. (2010),
doi:10.1016/j.ecolmodel.2010.09.017
[3] News, “Beijing has a scarae of water resources”, Accessed September 28, 2012, [Online]
Available: http://news.xinhuanet.com/politics/2011-08/12/c_121849553.htm
[4] Report, “Water resources in Beijing”,[Online], Accessed: October 5, 2012,
Available: http://www.bjwater.gov.cn/tabid/207/Default.aspx
[5] Article, “Beijing Air Quality”, [Online], Accessed September 28, 2012,
Available: http://www.beijing-travels.com/beijing_guide/overview/air_quality.html
[6] Yu Lei, Qiang Zhang, Chris Nielsen, Kebin H, “An inventory of primary air pollutants and
CO2 emissions from cement production in China, 1990e2020”,[Online], Accessed September 28,
2012, Available: http://mic.greenresource.cn/static/publications/lei_ae_2011.pdf
[7] Jimin Zhao, “Climate Change Mitigation in Beijing, China”, [Online], Accessed: October 5,
2012, Available:
http://www.unhabitat.org/downloads/docs/GRHS2011/GRHS2011CaseStudyChapter05Beijing.pdf
[8] Beijing Statics, “Resources, Energy, and Environment (2000~2009)”, Accessed: September
27, 2012, [Online] Available: http://www.bjstats.gov.cn/sjtjr/szbj/201009/t20100913_184701.htm
[9] Anjun Pan, “Water Management in Beijing”, [Online], Accessed: October 2, 2012, Available:
http://www.un.org/esa/sustdev/sdissues/water/workshop_asia/presentations/pan.pdf
[10] Jinghua Guo, Kenneth A. Rahn, Guoshun Zhuan, “A mechanism for the increase of pollution
elements in dust storms in Beijing” [Online], Accessed: October 5, 2012, Available:
http://environment.fudan.edu.cn/CACS/papers/A%20mechanism%20for%20the%20increase%20of%20polluti
on%20elements%20in%20dust%20storms%20in%20Beijing.pdf
[11] Article,” Beijing’s Vehicle Population Reached 3,765,000”, [Online], Accessed: October 5,
2012, Available: http://www.bjjtgl.gov.cn/publish/portal1/tab165/info13357.htm
[12] Article, Xin Dingding, “Beijing car restrictions to continue”, [Online], Accessed: September
28, 2012, Available: http://www.chinadaily.com.cn/bizchina/2009-04/06/content_7651378.htm
[13] Jun Yang, Joe McBride, Jinxing Zhou, Zhenyuan Sun, “The urban forest in Beijing and its
role in air pollution reductio”, Accessed September 27, 2012. [Online]
Available: http://www.fs.fed.us/ccrc/topics/urban-forests/docs/urban%20forest%20Beijing.pdf
[14] Li ZS, Yang L, Qu XY, Sui YM., “Municipal solid waste management in Beijing City”,
[Online], Accessed September 28, 2012, Available:
http://www.ncbi.nlm.nih.gov/pubmed/19375298