Table 9.2 List of thresholds of constraint indicators
Category
Indicator
Unit
Data source
Threshold
Environmental 1
Water footprint
based on blue
water
m
3
/
(personÁyear)
The Water
Footprint
Network.
Mekonnen
and Hoekstra
(2011)
4000 km
3
/
(personÁyear)
(from planetary
boundaries)
2
Amount of emissions of CO 2
t/
(personÁyear)
EDGAR
Judge whether the
state of the average temperature in
2100 will be 2
on
the Celsius scale
higher than that in
1850. (from
IPCC)
3
Quantity of solid
waste generated
kg/
(personÁyear)
Karak et al.
(2012)
UN-HABITAT. (2011)
Japanese
Ministry of
the Environment (2011)
no threshold. this
is a maximization
indicator
negative
contributor
4
Atmospheric concentration of Hg
μg/m
3
AMAP/
UNEP
1 μg/m
3 (annual
average)
(from WHO)
5
Atmospheric concentration of PM 10
μg/m
3
WHO
70 μg/m
3 (Annual
mean) (from
WHO)
Economic
6
Ratio of GDP per
capita (GDP per
capita in the city/
GDP per capita in
the country in
which the city is
located)
dimensionless The World
Bank
No threshold. This
is a maximization
indicator
Positive
contributor
7
Gini coefficient of
household income
dimensionless UNHABITAT
0.4 (from
UN-Habitat)
8
Congestion cost
(populationweighted average
distance to a city
center)
m
ORNL
No threshold. This
is a maximization
indicator
Negative
contributor
Social
9
Green rate (Ratio
of green areas to
urban areas)
%
GLCF
No threshold. This
is a maximization
indicator
Positive
contributor
(continued)
9 The City Sustainability Index (CSI): How Should the Sustainability of. . .
175