Administration Model for Urban Green Spaces in terms of Cool Island EffectYasushi MABUCHI, Kotaro AZUMA, Seigo NASU
Kochi University of technology
Recently, participation of NPO in the management of the urban green spaces has been increasing rapidly. In
these organizations (NPO), the operation and maintenance of urban green spaces including procurement ofmaterials and employment of engineers has been managed by the fee from the residential community and thesubsidy from the local government. This is a new concept of environmental management that the effect of theurban green spaces will be managed considering environment as “Resource” for generations and generations.
There is little case where an environmental quality is examined as administrative resources. The purpose ofthis study is to propose and evaluate an environmental administration model of the urban green spaces which
ha a good cool island effect and a harmonization between management method and cost and needs of thelocal community of the urban green spaces.
that makes the cool island effect of urban green

1. Backgroundspaces function effectively and derive optimum
The contingent evaluation method (CVM) and thefeature of urban green spaces balancing construct

travel cost method (TCM) have been proposed forand management cost of urban green spaces withthe evaluation model of environmental policy.

needs of residents.

Thesemethods

evaluatenottheresidents’consented value but the environmental effect as an

2. Outline of environmental administration

absolute

system of the urban green spaces

value.

The

environmental

value

isevaluated as an absolute value to develop theenvironment policy and the urban planning.

2.1 The environmental administration system

However, residents’ agreeable amount is relative

The environmental administration system of thisbecause of a peripheral environment, an social

study is to evaluate necessity of environmental

condition and a diversity of residents’ sense ofresources for residents, by comparing the amount ofvalues. Therefore, that evaluation does not reflect

willingness to pay of local residents and thewillingness to pay of local residents. In the case ofconstruction cost of urban green spaces under

implementation

andassuming that the residents defray construction andmanagement project of the urban green spaces, it ismanagement cost of environmental resources. The

necessary to propose the project valuation model

application of the environmental administration

including the plan, management, implementation

system is shown as follows;

and accountability of public project.

Application of administrative side

The objective of this study is to propose the- Plan and management of construction projectenvironmental administration system based on awhich corresponds to value of local residents’new concept of environmental management that theevaluation

effect of the urban green spaces will be managed- Accountability of construction project

consideringoftheenvironmentconstructionas“Resource”

forgenerations and generations. In addition, theApplication of company side

administration system of the urban green spaces- Basic information about purchase price and rent ofhousesand purpose. Takahara(1986) classifies the functionof the urban green spaces into 5 kinds such as

The advantages of applying the environmental

nature conservation, pollution protection, amenity

administration system are shown as follows;

and recreation. The willingness to pay is calculated

1) Easiness of setting the rental fee for publicin the each environmental function to examine theinstitutions based on a consensus between residents

environmental administration system of the urban

and the government.

green spaces.

It is easy to understand the amount of the limitation

The construction cost include from construction toof the payment, because the willingness to pay tomanagement of urban green spaces.

environmental resources is described in a function.
Environmental Effects
Equilibrium
Analysis2) Implementation of small government limitations
resources that are necessary for residents but also toimplement the government projects that are suitable
for their budget scale, because administrative policy

Environmental Investment
Plan

It is easy not only to construct the environmental

NPO Model
Cost effective
analysis
G(x)

F(x)

Private company
Model
Demand andSupply analysis∂F(x)demand∂G(x)local

inhabitants'

Cool island effectUtility functionf2(ｘ)Disaster prevent

Utility function
f3(ｘ)Wild life protect

Utility function
f4(ｘ)CO2 reduction

Utility function
f5(ｘ)Landscape effect

Construction Costis made in terms of the balanced point of thefor

Total benefit
functionF(ｘ)Utility function
f1(ｘ)environmental

Total costfunctionG(x)Cost function
g1(ｘ)Construction cost

Cost functiong2(ｘ)Management cost

resources and the necessary construction cost ofFig.

environmental resources.

1.

The

outlineof

theenvironmental

administration system of urban green spaces
3)

Securingof

projecttransparency

andaccountability
It

is

easy

2.3 The Analysis model of the environmental
toenvironmental

understandpolicythegroundsofadministration systemselection,

becausetheTheanalysismodeloftheenvironmental

construction cost of environmental resources andadministration system consists of NPO type andthe utility for residents are described in a function

general corporate type in terms of the way of profit

and used criterion for policymaking.

distribution and characteristic of the implementingorganization.

2.2

The

outlineoftheenvironmental
1) NPO typeadministration system of urban green spaces
theA relationship diagram of the income and expenseenvironmental administration system of urban

from construction the urban green spaces are shown

green spaces.

in Fig. 2.

Fig.1

shows

thewhole

structureofisIn this case, the urban green spaces that arecomposed by two functions of the environmental

constructed in land cover ratio T0 bring the balance

utility and the construction of urban green spaces.

with the cost and benefit C0 yen. The balance point

The utility function of urban green spaces is theP between the income and expense becomes theenvironmental cost that residents feel the necessity

turning point of operation approval in the case of

to get some effects from green and pay to the urban

NPO (without profit) If the management agency is agreen spaces. In general, the function of the urban

local government, this willingness to pay becomesgreen spaces is classified by their characteristics

the tax or a usage charge which propriety have to beTheenvironmental

administration

systemimplement effective management by deriving

asked to the residents.

area-specific demand and supply curve andMoney

selecting a construction project near the balanced

ＰC0

point. If the organization without profit such as

Incomefunction

NPO implements management of environmental
resources, the profit corresponding to triangle
QCsC1 can be diverted to construction andmanagement cost. And if the all profits divert to theExpense
Function
ＯT0smallcost and the interest rate is disregarded, thelarge

Environmental effectbalanced point P of the income and expense in Fig.
2 become a possible point of the management.

Fig. 2. The analysis model of the environmental
Moneyadministration system (NPO type)

Cd

Supplyfunction2) General corporate type
Feasibility of the environmental administration thatＱ

is implemented by a private company is examined

C1

based on introduction of concept of the market
Ｃsmechanism and the marginal analysis for theenvironmental administration of the urban greenＯ

spaces bringing maximization of social benefits.
The marginal cost and the willingness to pay show
the supply curve and the demand curve of average
local residents. Fig. 3 shows the supply and theDemandfunction
Ｔ1

smalllarge

Environmental effectFig. 3. The analysis model of the environmental
administration system (General corporate type)demand relationship of constructing the urban green
spaces.

3.

Point Q that is the balanced point of the demandadministration model from viewpoint of the cooland the supply in Fig. 3 is combinations of land

island effectAnalysismodelofenvironmental

cover maximizing a social total surplus. At this time,
rectangle QCsOT1 shows a total of the construction

The resources in administration are 1) capital, 2)

and management cost of the urban green spaces perman

annum. On the other hand, rectangle QCdCs shows

Environmental

a social total surplus from the construction of the

combination of these resources. The cool island

urban green spaces. QCdC1 represents an effect that

effect of the urban green spaces produce utility

the local residents can obtain from constructing thefrom combination of the construction of urban

urban green spaces decreasing temperature T1

green spaces (capital), the implementation anddegree Celsius (Consumer’s surplus). Triangle

management (man power), and cool island effect

QCsC1 is the maximum value of the profit that the(physical recourses), and the cool island effect canprivate company can obtain through collecting the

be manageable project. Here, the utility for theC1 yen from the local residents. When the privateorganization that construct the urban green spaces iscompany manages the urban green spaces asincome obtained as a tax or a use charge from local

environmental resources, the private company can

residents who enjoy the benefit of environmental

power,andeffects

3)

physicalareresources.

producedfromeffect of the urban green spaces. The cost is theBoundary Area (200m)(100m)

境界層（ 1 0 0ｍ ）construction cost and management cost.

This air cell is cooled
byこthelatentの空
気 塊 heatが 潜 flux.
熱フラックスにより冷却

3.1 The creation of utility function in cool islandeffectThe utility function of the urban green space in

Urbanized住Area
宅地

Urbanized住 宅Area
地

都市 緑Area地Green

terms of cool island effect is calculated byconsidering electricity bill produced from using air
conditioner during summer season and regardingsaving amount of electricity bill from temperature
reduction by installation of the urban green space asFig.. 4.

Concept of temperature decrease

potential

WTP for the cool island effect of the urban green

1. Calorie from the roof and ceiling

Roof（Concrete, Thickness10cm）

space. This value is reduction volume of living costthat the resident can obtain, and it is strictlydifferent from the willingness to pay of residents.
WTP for the cool island effect is estimated from thefollowing 3 phases; a) Quantification of cool island

8. Ventilation loss
2. Calorie from thewall

6. Heat flux ofhuman body

⑦Calorie from the lump

3. solar radiation that entersby a window

2.5m

4. Calorie by temperaturesfluctuate in inside andoutside of window

Window（Plate glass, Thickness3mm）

effect, b) Calculation of air-conditioning charge per
5. Calorie from the floorFloor（Concrete, Thickness10cm）

one family by applying the indoor heat transmission
3.82m

model, c) Calculation of WTP induced from theconstruction of the urban green spaces.

Fig.. 5. The indoor heat transmission modela) Quantification model of cool island effectc) Calculation of WTP by constructing of theThe utility function of the cool island effect is aurban green spaces

function to estimate the amount of temperatureThe

depression based on the parameter defined from thetemperature with and without construction of thearea of land cover constituting the urban green

urban green spaces are calculated using the indoor

spaces. Assuming that the air parcel over the urban

heat transmission model. The amount of reduction

green spaces is cooled only by the latent heat flux,

for electricity bill is calculated from the difference

the amount of temperature depression under theof the expected values between the present

surface boundary layer is estimated (Fig. 4.). The

temperature and the urban green spaces installed

effect of the sensible heat and the advection is nottemperature based on the result of the energy

treated in this study.

conservation questionnaire.

b) Calculation of air-conditioning charge per one

3.2 Calculation of cost function of the cool islandfamily by the indoor heat transmission model

effect

The indoor heat transmission model which is shown

The environmental cost of the urban green spaces isin Fig. 5 is applied for calculation of saving amountestimated by the sum of the construction cost andof electricity bill resulting from establishment of

the management cost. The management cost was

the urban green spaces.

calculated from the management items to maintainair-conditioning

costsoftheoutside

the trees, grass land and water body (Table. 1.,2).
Table. 1. The unit of the planting works

temperature reduction potential is calculated underWood area

Grass area

the condition of the limitation of land cover As aUnitUnit(perItem
Volume (per 100Volumetrees)
100m2)
Organizer
3.2 Person
Organizer
0.2 person
ManManEngineer
16.1 Person
Engineer
1.1 person
powerpower
Worker
9.6 Person
Worker
2.3 person
Camphor
100 trees
100 m2
DirectDirect Grasstree
costcost
Soil
2.7 m3
OthersOthers5%5%
Itemresult, the construction cost for the each unit of thetemperature reduction potential is high on thefollowing line l.

l : x1 = 2 x2 = 0.8 x3

Item
Camphor tree
Cost ofGrassmaterials
Soil
Organizer
Laber cost Engineer
Worker…………………

x1 ≥ 10,000

Table. 2. The unit price of the planting works(1)Here, x1 is glass land area(km2), x2 is forest

VolumeInit
5000 trees/yen
480 yen/m2
1000 yen/3l
21100 yen/day
16100 yen/day
15700 yen/day

area(km2), and x3 is water surface area(km2).
Here, the reason why the combination of efficientland cover shown in equation (1) becomes a straightline in the (x1,x2,x3)-space is that the temperature
reduction model in this report is linear. Fig. 6.

4. The environmental administration analysis forshows the relationship between the temperature

the protection of the cool island effectreduction potential and construction cost on the linel.

4.1

Casestudyintheenvironmental

administration system

Money（Yen）(Construction+Management) Cost
Willingness to pay

The initial condition of the case study is assumed asfollows;

Pa) The urban green space is constructed in the1082.56

Grass:5.0ha
Wood Area：6.3ha
Water body：2.5ha

2unused area covered by 20ha asphalt in the 1km
residential area.

b) The number of the local residents of this area isassumed to be 15000.
c) 15000 people obtain the various environmental
effects due to the construction of the urban green
space and are charged the necessary cost to manage

1.826℃

Cool island effect（℃Fig. 6. The result of the environmental
administration analysis (NPO Type)environmental effect.

In this case study, according to the administrationd) The environmental effect of the urban green

analysis of the balanced point between the total

spaces is including the cool island effect, the global

construction and management cost per a person andwarming controlling effect, and the effect of thethe total willingness to pay of residents per a person,landscape.

as shown in Fig. 8, the balanced point P composede) The redemption period in the urban green spacesof the glass area of 5ha, the water surface of 2.5ha

is assumed to be 50 years, and redeems evenly

and the trees area of 6.3ha has potential of

every year.

temperature reduction of 1.83 degree Celsius andthe income from the management of the urban

4.2 The environmental administration analysis

green spaces is estimated to be about 16 million,

for the protection of the cool island effecttherefore, the point P is proved as the possible

First, the construction cost for the each unit of thelimits of environmental administration for NPO.

Therefore, the urban green spaces administration

cool island effect derived from the urban green

plan which is brought closer to the point P isspaces by comparing the benefit obtained from theessential for the NPO administration. Next, we arecool island effect and the cost calculated from thegoingofconstruction and management of the urban green

environmental administration system by the privatespaces. When assuming that three environmental

company. Figure 7 shows the relationship between

effects are selected from the public function of thethe temperature reduction potential and theurban green spaces and the construction cost is

demand-supply curves in the construction of the

fairly distributed among stakeholders, possibility ofurban green spaces.

existence of the balanced point between theMoney(Yen)

construction cost and the income and of thetoexamine

about

thepossibility

596

environmental administration system from the
Supply Curve

construction to the management are approved in the595

case594

Demand CurveAtpresent,

thisenvironmental

administration system has the problems to beQ

592.7

593

study.

solved such as the accuracy of the system and theGrass:3.0ha
Wood Area：3.8ha
Water body：1.5ha

592

1.088

adaptability to the field. This system is expectedthat not only the policy making supporting tool

591
00.5

1

1.5

2

2.5

3

Cool island effect (℃)

from the construction to the management of theFig. 7. The result of the environmental

urban green spaces but also the function asadministration analysis (General corporate type)accountability to the local residents.

If the construction of the urban green spaces is

5. The challenges for achievement of theconducted under the balanced point Q which hasenvironmental administration system

the land cover composition of grass area of 3.0ha,
woods area of 3.8ha and water body of 1.5ha,

theThe improvement to generalize the environmental

air temperature reduction potential is estimated toadministration system is obtained by reconsidering

be 1.09 degree. In this case, the construction andthe evaluation model of quantification and forecast

management cost in terms of the cool island effectof cool island effect and environmental economy.

protection is estimated to be 8.9 million yen. TheThe challenges for the accuracy improvement of theprofit of the private company managing the urban

management system are shown as follows.

green spaces shown in the CQB area in figure 9 is

(1) Reconsidering of utility function in the cool

estimated to be 9311 yen per a year. Demand andisland effectsupply functions shown in figure 9 are the functions(2) Accuracy improvement of cool island functionof the air temperature reduction potential in the(3) Accuracy improvement of cost function ofoptional thermal condition.

construction and management of the urban greenspaces

In the future, high accuracy balance analysis using(4) Necessity of construction of the comprehensive

the function considering the supply cost increase

environmental administration system of the urban

and the decreasing the demand (willingness to pay)green spaces including the other environmental

is essential for lower thermal condition. In thiseffect such as the ecosystem protection effect andstudy, we develop the environmental administration

the disaster prevention effect.

system in the urban green spaces in terms of theReferences
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Junsei KONDOH 2000. The meteorology of theWater cycle, Asakura Syoten: pp128-138 (Book)
Kiyoyasu IMAKI 1993. The engineering of heating
and air conditioning, Sangyo Tosho Co., Ltd.:
pp37-55 (Book)
The energy conservation center 2005. Energy
Conservation Measures in the consumer sector(Book)
Construction Research Institute 2002. The unit
price of the construction project: pp500-503