Post on 18-Jul-2020
1
Application of CASBEE-City to Various Types of Cities around
the World
Speakers:
Takigami, Masaki1; Ikaga, Toshiharu
2; Murakami, Shuzo
3; Kawakubo, Shun
4
1 Keio University, Yokohama, Japan
2 Keio University, Yokohama, Japan
3 Institute for Building Environment and Energy Conservation, Tokyo, Japan
4 Hosei University, Tokyo, Japan
Abstract: Conducting city assessments can help municipalities determine appropriate measures for
sustainability. However, most city assessment tools are designed for assessing cities in developed
countries, with a particular focus on megacities. This paper describes how an assessment tool for
various types of cities worldwide has been adapted from the “CASBEE for Cities” tool, which was
originally designed for assessing Japanese cities. First, the tool is validated by assessing whole
municipalities in Japan. Generally, in Japan, living standards are higher than the world average and
the environmental load is also correspondingly higher. These findings are verified quantitatively by
using the tool. To extend the tool’s utility beyond Japan, a rapidly developing municipality in
Malaysia is assessed to verify the tool’s practicality in other types of cities. Assessment data were
gathered through interview surveys and used as input to the tool. The results quantitatively show that
conditions in the city should be improved.
Keywords, CASBEE, Foreign City Assessment, Triple Bottom Line, Environmental Efficiency,
Public Statistical Information
1. Introduction
As of 2008, more than half of the world’s population is living in urban areas; this figure is
expected to rise to 70% by 2050. In today’s era of cities, more and more cities around the
world are making efforts to become more sustainable. Adoption of the Charter of European
Sustainable Cities and Towns Towards Sustainability, also known as the Aalborg Charter, has
increased awareness of the importance of actions at the city level to create a sustainable
society.1 In recent years, many academic investigations of city assessments for sustainability
have been conducted. For example, the GaWC study,2 Global Cities Index,
3 Global Power
City Index,4 and Global City Competitiveness Index
5 are several well-known city assessment
indices. However, most city assessment tools and indices are developed for assessing only
domestic cities or are specifically designed for assessing cities in developed countries due to
the availability of and access to data for these types of cities. In this study, an assessment tool
for cities around the world is developed. Cities of every type and size can be assessed by the
tool if the data necessary for assessment are gathered.
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2. Methodology
2.1 Development of an Assessment Tool for Cities around the World
This section describes modifications to the Comprehensive Assessment System for Built
Environment Efficiency (CASBEE) for Cities tool (hereinafter, CASBEE-City) to allow for
assessment of cities around the world. Originally, the tool was designed for assessing
municipalities in Japan.6,7,8
CASBEE-City assesses whole municipalities in Japan and enables
understanding of the actual conditions in each municipality in terms of environmental, social,
and economic aspects.
2.2 Assessment for Quality
CASBEE-City calculates each city’s score by using a large database in which information on
various cities is stored. The database
information is modified for use in
the tool. Figure 1 and Equation 1
show the assessment methodology
and the scoring function for quality.
The score for quality is calculated
according to a continuous function
so that the effect of measures
implemented by municipalities
accurately reflects the amount of
effort. The scoring function should
be different for each assessment
item in the subcategory to make the effects of city actions become apparent. As a
consequence, a cumulative relative frequency (i.e., percentile rank) curve has been adopted as
the scoring function for each subcategory and these subcategory results are converted into the
overall score. Histograms and graphs are created for each quality subcategory. The score for
quality is calculated on this curve by applying weight coefficients to scores in various major,
minor, and subcategories. The target city is assessed “relatively,” with the percentile score
depending on the group being assessed. The assessment group in CASBEE-City is set to
“whole municipalities in Japan.” In this study, this assessment group has been expanded to
assess whole cities around the world. In other words, each scoring function has been
customized. To expand the range of each assessment item, public statistical data has been
collected from around the world. For practical reasons, rather than using data for only cities,
national data are collected. In the original version, city-level data are desirable for creating the
scoring function. However, to expand the tool, national-level data are used as averages for all
cities in each country, and each scoring function is created as follows.
−∑ ×
×∑
∑ ××= 1)(25
ii
wij
w
kijk
wijk
QQualitytalEnvironmenforScore j (1)
Figure 1. Scoring method for quality
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Each subcategory (Qijk) is assessed on a five-point scale corresponding to the conditions in a
city (higher scores indicate higher sustainability). In Equation 1, w (0 ≤ w ≤ 1) values are
category weights, with subscripts corresponding to major (i), minor, (j), and subcategories (k).
Table 1 shows the assessment items for CASBEE-City before and after the modifications for
worldwide use. Assessment items in the modified tool should be broadly the same as in
CASBEE-City. However, some assessment items have been converted to similar or more
suitable items to apply the tool to a broader range of cities rather than just Japanese cities.
National statistical data are collected from various organizations, such as the United Nations,
World Bank, and World Health Organization, whose statistical data can be considered as
Table 1. Assessment items for quality and load (Upper: original items; lower: modified items)
Category Assessment item
Major Minor Subcategory (original items)
Qu
alit
y Q
Q1
. E
nv
iron
men
tal
asp
ect Q1.1
Nature conservation
Q1.1.1
Ratio of green and water spaces
(Forest area + Major lake area) / Total land area
No change
Q1.2
Local environment
Q1.2.1
Air
The number of days which hourly photochemical oxidant concentrations during the day are 0.12
The average annual exposure level of the average urban resident to outdoor PM10
Q1.2.2
Water
75% of daily average biochemical oxygen demand in a river
Proportion of the population using improved drinking water sources
Q1.3
Resources recycling
Q1.3.1
Recycling rate of general waste
Recycling rate of general waste
Municipal waste collected / Total population
Q1.4
CO2 sinks
Q1.4.1
CO2 absorption by forests
Current forest area * unit of absorption (2.92 t-CO2/ha) / Adjusted population
No change
Q2
. S
oci
al a
spec
ts
Q2.1 Living environmental
Q2.1.1 Adequate quality of housing
Total floor area per dwelling unit
Q2.1.2 Traffic safety
Number of traffic accidents / Adjusted population
Number of road traffic deaths / Total population
Q2.1.3
Crime prevention
Number of crimes recorded / Adjusted population
Number of intentional homicide / Total population
Q2.1.4
Disaster preparedness
Number of disaster response hospitals per 100,000 persons in adjusted population
Number of hospital beds / Total population
Q2.2
Social service
Q2.2.1
Adequacy of education service
Number of students at elementary and junior high schools / Number of teachers at elementary and junior high schools
No change
Q2.2.2
Adequacy of cultural services
Number of community centres + Number of libraries / Land area of municipality
Number of Internet users / Total population
Q2.2.3
Adequacy of medical services
Number of physicians / Adjusted population
No change
Q2.2.4
Adequacy of childcare services
Number of childcare facilities / Infant population (aged 0 to 4)
Number of pre-primary students / Infant population (aged 0 to 4)
Q2.2.5
Adequacy of services for the elderly
Number of senior care facilities / Senior population ( aged 65 and over)
Number of nurses and midwives / Total population
Q2.3
Social vitality
Q2.3.1
Rate of population change due to births & deaths
Rate of increase / decrease in the natural population = Increase / decrease in the natural population in one year
Rate of population change due to births, deaths and migration
Q2.3.2
Rate of population change due to migration
Rate of population change due to migration = Number of new residents
(Male life expectancy + Female life expectancy / 2
Q3
. E
cono
mic
asp
ects
Q3.1
Industrial vitality
Q3.1.1
Amount equivalent to gross regional product
(Agricultural output + Value of manufactured goods shipments + Annual sales of commercial goods) / Adjusted population
GDP (Gross Domestic Product) / Total population
Q3.2
Financial viability
Q3.2.1
Tax revenues
Tax revenues the local government / Adjusted population
Number of employed persons / Total population
Q3.2.2
Outstanding local bonds
Real debt service ratio
Number of unemployed persons / Labor force size
Q3.3
Emissions trading
Q3.3.1
Amount of emissions trading
Existence or nonexistence of emissions trading
No change
Lo
ad
CO2 emissions per person
Total CO2 emissions from each sector / Adjusted population
Total CO2 emissions from each sector / Total population
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objective and reliable.
2.3 Assessment for Environmental Load
Equation 2 shows the assessment methodology for environmental load emitted from the target
city. CASBEE-City converts the total amount of CO2 emissions per capita into a score from 0
(good) to 100 (poor).
)exp(11100
aXLoadtalEnvironmenforScore
−+×= , where X=log10 x-log10µ (2)
As in CASBEE-City, CO2
emissions are converted to a score
by using a logistic equation.
However, because the range of
CO2 emissions can range from
virtually nothing to an extremely
large value globally, the
assessment range is expanded in
the modified tool. Thus, the
explanatory variable for CO2
emissions is converted to a
logarithmic scale. Here, a is the
gain, which controls the curvature of the logistic curve, x represents the amount of emissions
from the target city, and µ represents the present world average emissions amount. Figure 2
shows the curve created by the logistic equation. Two reference points have been set. First,
CO2 emissions equal to the present world average rate is assigned a value of 50 points. When
the value of x is 0.94 t-CO2/person/year, 12.5 points is assigned as a second reference point,9
which is the point where the target city achieves an 80% reduction over the current world
average, in accordance with the long-term target for developed countries.
3. Results and Discussion
3.1 Reassessment of Whole Municipalities in Japan
Whole municipalities in Japan were reassessed using the modified tool for verification against
the prior model. All assessment items must be checked for validity because some assessment
items have been changed in the modified tool.
Figure 3 compares the results for the quality of whole municipalities in Japan as assessed by
the original and modified tool, using the assessment items in Table 1. The left figure shows
the quality scores using the original and modified assessment items. Only small differences in
quality scores were observed after assessment items were changed (the slope of the regression
line is about 1). The assessment items are also quantitatively verified to some extent because
variation of the score differences between the original and modified items are small (the
standard deviation of the score differences is about 6.47). The right figure shows the quality
Figure 2. Scoring method for environmental load
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scores using the original and modified assessment range. “After modified” corresponds to the
world assessment range and “Before modified” corresponds to the Japanese assessment range
(i.e., from CASBEE-City). All plots are located above the diagonal, in other words, score for
whole municipalities were improved after assessment range was expanded. This means that
the living standard in municipalities in Japan exceeds the world average (= 50 points).
Figure 4 shows the assessment results for whole municipalities in Japan using the modified
tool. The results are shown on a two-dimensional built environment efficiency (BEE) chart in
which the vertical axis and horizontal axis show city quality from 0 (worst) to 100 (best) and
environmental load imposed by the city from 0 (best) to 100 (worst), respectively. The main
contribution of this study is expanding the Japanese assessment scale of the original
CASBEE-City tool to be a global assessment scale. For example, a score of 50 points is
updated in the world city tool to indicate the world median score instead of the median score
in Japan. Almost all municipalities in Japan exceeded 50 points for both quality and load.
This means that the living standard in Japanese municipalities exceeds the world average. On
the other hand, most Japanese municipalities impose an environmental load greater than the
world mean (where 50 points corresponds to 4.56 t-CO2 annually per capita), so reductions in
CO2 emissions are required.
3.2 Assessment by Field Survey of a Rapidly Developing Municipality in Malaysia
After the modified tool was developed, Putrajaya
city (located south of Kuala Lumpur), a rapidly
developing municipality in Malaysia, was assessed
to test the practicality of the tool. Figure 5 shows
an aerial view and photos of the city. A field
survey to collect necessary statistical data for
assessment was conducted through interview
Figure 4. Comprehensive assessment results for whole municipalities using the original (left) and modifed
(right) tool
Figure 7. Assessment result for minor assessmnet categories
Figure 5. Map and Photos of Putrajaya
Figure 6 Assessment results of Putrajaya
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surveys and input into the tool. However, some data which were not available for the
municipality were replaced with Malaysian average values. Figure 6 shows the assessment
results for Putrajaya city. The BEE for Putrajaya is currently slightly lower than the world
average of 1.0. This result indicates that, from a sustainability perspective, load reduction is
more urgent than improvements in quality. Figure 7 shows results on the minor assessment
categories shown in Table 1. Almost all scores are higher than the world average of 3.00
points. From Figure 5, it can be seen that lakes and green space are adequate and, as a result,
the score for Q1.1 is high. However municipal waste (Q1.3) is being collected by the
municipality or a company at less than the world average level. This indicates that
implementing waste-related measures should have a higher priority than other environmental
measures. It is also necessary to increase amount of CO2 absorption (Q1.4). In the report
“Putrajaya Green City 2025,” a total of one million trees are planned to be planted in
Putrajaya by 2025.10
Although this effort has not been quantitatively assessed yet, the score
will be drastically improved when the plan is carried out. Social aspects (Q2) of Putrajaya
score much higher than the world average. The main cause of the high score for Q2.1 is the
high security level of the city. No murders occurred in Putrajaya during the target year. Social
services (Q2.2) also scored higher than the world average. The construction of Putrajaya was
started in 1995, and almost all governmental functions have been transferred to the city. Many
kinds of social functions are sufficient. This transfer of governmental functions also will
result in a high score for Q2.3 because the population will be concentrated in the capital. The
employment rate is high and unemployment is low in Putrajaya. Although the score is high,
many personnel are working in government agencies, rather than private businesses. It should
be noted that this employment system is rather unique compared with many other cities, but
these assessment results are tentative. To finalize the results, continued cooperation with the
local government at Putrajaya is required.
Acknowledgements
We thank the administrative officers in Putrajaya City, whose support and insightful
comments were invaluable during the course of this study. We also give special thanks to the
Committee for the Development of an Environmental Performance Assessment Tools for
Cities (Chair Shuzo Murakami) for providing advice that was essential to the successful
conclusion of this study.
References
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(available at:
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http://www.atkearney.com/documents/10192/4461492/Global+Cities+Present+and+Future-
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(8) Kawakubo, Shun; Ikaga Toshiharu, Murakami Shuzo and Asami Yasushi (2013),
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