gis-based greenery evaluation on campus master plan

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Available online at www.sciencedirect.com

Landscape and Urban Planning 84 (2008) 166–182

GIS-based greenery evaluation on campus master plan

Wong Nyuk Hien, Steve Kardinal Jusuf ∗Department of Building, National University of Singapore, 4 Architecture Drive, Singapore 117566, Singapore

Received 1 February 2007; received in revised form 2 July 2007; accepted 22 July 2007Available online 4 September 2007

bstract

In the previous study, it was found that urban heat island intensity in National University of Singapore (NUS) campus as high as 4 ◦C at around3:00. It is also concluded that the presence of dense greenery in NUS environment is very important in keeping low ambient temperature.

National University of Singapore has announced its new master plan in 2005, entitled NUS Master Plan 2005. Many new buildings will be builtnd in some areas existing greenery will be removed. Geographical Information System (GIS) was use to evaluate the greenery condition. It wasound that the greenery rate of NUS Master Plan 2005 will drop by about 3% from 55.10% of NUS current condition to 52.31%. In order to havesustainable environment, the greenery condition should be at least maintained at the same rate or even make it better.For this purpose, potential of increasing greenery area by rooftop greenery application was also done. The target is to maintain the green rate of

ifferent zones at the same rate with current condition. In total, there will be more than 56% new buildings in NUS Master Plan 2005. Therefore,
here is a good opportunity to plan and introduce the rooftop greenery or vertical greenery since in the early design stage.
The ENVI-met simulation predicts that the ambient temperature in NUS environment will increase about 1 ◦C when NUS Master Plan 2005 isompleted. It is due to the reduction of greenery rate.

2007 Elsevier B.V. All rights reserved.

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eywords: NUS campus; GIS; Master plan evaluation; Potential of rooftop gre

. Introduction

Temperature in urban area is increasing every year. In Europe,arious studies on the intensity of the urban heat island haveeen done for many cities. A daily upper docile limit of 3.1 Kas reported by Chandler (1965) in a comparison of Kensington

nd Wisley over a period of 10 years. Lyall (1977) observed theverage magnitude of the nocturnal heat island effect was 2.5 K
n June and July in London. An average heat-island intensity ofround 7 K was found by Barring et al. (1985) during the winternd spring seasons in Malmo, Sweden. Eliasson (1996) observed
Abbreviations: FASS, Faculty of Art & Social Science; GIS, Geographicalnformation System; IMRE, Institute of Materials Research and Engineering;2R, Institute for Infocomm Research; KE7, King Edward VII; KRH, Kentidge Hall; LT, Lecture Theater; NUS, National University of Singapore; OED,ffice of Estate and Development; PGP, Prince George’s Park; UCC, Universityultural Centre; UH, University Hall; SDE, School of Design and Environment;H, Shears Hall; SLSS, Singapore Synchrotron Light Source; SRC, Sport &ecreation Centre; YIH, Yusof Ishak House∗ Corresponding author. Tel.: +65 65164691.

E-mail addresses: [email protected] (N.H. Wong), [email protected]. Jusuf).

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169-2046/$ – see front matter © 2007 Elsevier B.V. All rights reserved.oi:10.1016/j.landurbplan.2007.07.005

; ENVI-met simulation; Temperature prediction

rural–urban temperature difference of 5 K in Goteborg, Swe-en. The heat-island intensity observed in Essen, Germany bywaid and Hoffman (1990) was between 3 and 4 K for bothaytime and nighttime.

Based on the urban heat island research in Singapore (Wong,004), in 20 years, the temperature in urban area has increased◦C and in the long-term minimum temperatures differencesetween urban–rural, ranging from 0.3 to 1.9 ◦C. In continu-nce of this Singapore urban heat island study, a micro scale UHItudy has also been done (Wong et al., 2007a) at National Uni-ersity of Singapore campus (Fig. 2). It is found from the fieldeasurement that on a typical day, that the peak temperature

ifference between dense green area (Kent Ridge Road-Waterank) and PGP residence can be as high as 4 ◦C at around3:00. When the time approaches mid-night, the temperatureifference between these two locations is about 3 ◦C. Follow-ng this field measurement result, GIS-based temperature mapsFig. 1) have also been developed and discussed more detail in
he separate paper. From the ENVI-met simulation (Bruse andleer, 1998; Bruse, 2007), it is concluded that the presence ofense greenery in NUS environment is very important in keepingow ambient temperature. Cooling effect produced by greenery
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mailto:[email protected]

dx.doi.org/10.1016/j.landurbplan.2007.07.005

N.H. Wong, S.K. Jusuf / Landscape and Urban Planning 84 (2008) 166–182 167

ature

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Fig. 1. Temper

ill affect NUS microclimate positively as it will make NUSnvironment cooler in general. From TAS (EDSL, 2006) simu-
ation, it shows that the overall energy savings of cooling loadange from 3.29% to 9.08% by applying turfing, 6.73–18.85% bypplying shrubs and 7.16–20.01% by applying trees. By plant-
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Fig. 2. NUS curre

map at 15:00.

ng trees and intensive rooftop system, the energy saving is muchigher.

Some researchers have also simulated the performance ofooftop greenery. McPherson et al. (1988) found in four cities inS that dense shade on all surfaces reduced peak cooling loads

nt site plan.

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68 N.H. Wong, S.K. Jusuf / Landscape

y 31–49%. Meier (1990/1991) also found that air-conditioningnergy savings can be up to 80%, although 25–50% was moreommon.

In the previous studies done in Singapore, Wong et al.2007b) and Wong and Yu (2006) confirm the simulation resultsbove on the performance of two different rooftop systems.ooftop greenery can provide benefits not only to the build-

ng but also the environment ambient temperature condition.ith intensive system, the surface temperature may reduce up

o 31 ◦C and the ambient temperature at 1 m may reduce upo 1.5 ◦C. The impact of rooftop greenery is even more pro-ounced for metal roof. Without plants, the metal surface cane up to 60–70 ◦C during daytime and lower than 20 ◦C atight. With plants, it ranges from 24 to 32 ◦C only. The effectf LAI values on the surface temperature fluctuating can belearly noted from the variations observed from dense plants,parse plants and weed. The benefits of reducing the surfaceemperature by greenery can be observed from mean surfaceemperature differences between the hard metal surface andhose below the plants. They are 4.7, 1.9 and 1.4 ◦C with theresent of the dense plants, the sparse plants and the weed,espectively.

Dam et al. (2000) reported indoor temperature of a building◦
ith a green roof is usually 3–4 C lower than an outdoor sum-
er temperature between 25 and 30 ◦C. Takakura et al. (2000)ound the inside air temperatures for the ivy covered model wereuch lower in the daytime and higher at night around 24–25 ◦C,

dros

Fig. 3. NUS New Ma

rban Planning 84 (2008) 166–182

ompared with those in the bare concrete model. The studiesbove are shown the importance and benefit of greenery. There-ore, it is necessary to preserve and to improve the greeneryondition in an environment.

In year 2005, National University of Singapore (NUS)eleased NUS Master Plan 2005, Fig. 3, as a response to therowing demand of the University development. As part of themplementation, NUS opened up land to build new buildings.t transformed the land use from green spaces into buildingFig. 4). The greenery area is reduced and it is expected thathe ambient temperature of surrounding the area will rise. To

aintain the ecological balance, the greenery area should beeplaced or relocated at that place. Fig. 5 shows the satellitemage of NUS campus. This study is to provide in depth analy-is the environmental changes in terms of greenery conditions one of the indicators and provide alternative scenarios toaintain it.In this paper, an evaluation on NUS Master Plan 2005 will

e discussed, providing the quantified data on its urban ele-ents (building, pavement and greenery). Comparison with theUS current condition greenery will also be provided, including

ome suggestions to improve its greenery condition, includingooftop greenery. Temperature prediction simulation was also
one to compare the temperature condition between NUS cur-ent site plan and NUS Master Plan 2005. Thermal performancef planting more greenery on NUS Master Plan 2005 was alsoimulated.
ster Plan 2005.


Fig. 4. Change of land use, removing green space become building.

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. Methodology

The main analysis tool for this study is Geographical Infor-ation System (GIS). Many researches make use of GIS as

heir analysis tool; especially in relation with Geographical dataKoster, 1998; Katzchner et al., 2004; Ao and Ngo, 2000). It isecause GIS presents an excellent way of transferring complexcientific information into a form that can be easily understoody decision makers and the general public (Matzarakis et al.,004). GIS has the capability in calculating the true three dimen-ional of areas. It gives the benefit because NUS complex is ailly terrain area. Overlaying two data, NUS site plan and ter-ain data, GIS can generate the true three-dimensional model ofUS campus and provide the calculated data.

.1. Quantifying greenery area of NUS Master Plan 2005

NUS Master Plan 2005 was divided into 11 zones, based on
he roads as the boundary of the each zone, as listed below:
1. Zone 1: University Cultural Centre (UCC) and Office ofEstate & Development (OED)

2. Zone 2: Sport & Recreation Centre (SRC)

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of NUS campus.

3. Zone 3: School of Design and Environment (SDE) and Fac-ulty of Engineering

4. Zone 4: University Hall (UH) and Yusof Ishak House (YIH)5. Zone 5: Faculty of Science6. Zone 6: Faculty of Art & Social Science (FASS) and Faculty

of Law7. Zone 7: King Edward VII (KE7), Institute of Materials

Research and Engineering (IMRE) and Singapore Syn-chrotron Light Source (SLSS)

8. Zone 8: Eusoff Hall and Temasek Hall9. Zone 9: Kent ridge Hall (KRH) and Shears Hall (SH)0. Zone 10: Institute for Infocomm Research (I2R)1. Zone 11: Prince George’s Park (PGP)

This zoning division was done to follow the same zoninglassification which has been done for the NUS current site plann order to compare the building–pavement–greenery area ofhe two plans. The purpose of this zoning division for the NUSurrent site plan is to calculate the Green Plot Ratio (Ong, 2003),
method to quantify the greenery condition. The zoning division
s also to facilitate Office and Estate Development in planningf the Estate improvement. The result on the NUS current sitelan Green Plot Ratio analysis is discussed in the separate paper.

170 N.H. Wong, S.K. Jusuf / Landscape and Urban Planning 84 (2008) 166–182

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Fig. 6. The whole NUS complex—

In GIS, the NUS Master Plan 2005 was extracted the greeneryrea, building area and pavement area. Shapefiles for these threereas were made in accordance with the data provided by Officestate and Development (OED) NUS. The building area wasalculated based on 2D plan area. Meanwhile, the 3D shapefilesor greenery and pavement areas were generated and calculated.

.2. Quantifying potential of rooftop greenery

Since a lot of new buildings are going to be built, there areany opportunities to plan and design to be more environmen-

ally friendly, such as introducing rooftop garden or verticalreenery. Therefore, the old and new buildings are identifiednd quantified to see its rooftop garden potential. Three scenar-os were calculated to find the rooftop garden potential. They are5%, 50% and 75% rooftop of new buildings used as rooftopreenery, respectively.

.3. Evaluation on NUS Master Plan 2005

In order to evaluate the NUS Master Plan 2005, comparisonith NUS current condition was made in terms of its urban ele-ents (building–pavement–greenery ratio). Especially for the

reenery condition, the changes of green rate were identified inach zone.

.4. Temperature prediction on NUS Master Plan 2005

ENVI-met simulation was used to predict the ambient tem-erature. The simulations were conducted in two different scales,s follows:

a The whole NUS complex, with two different scenarios: NUSMaster Plan 2005 (as designed) and NUS Master Plan 2005with increased trees, see Fig. 6. The results of these two
scenarios were also compared with the current conditionENVI-met simulation result.Part of the Faculty of Engineering, with four scenarios: Asdesigned, application of grass on the rooftop, application of
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cenarios in ENVI-met simulation.

trees on the rooftop and application of trees on the rooftopand on site, see Fig. 7.

Basic settings were employed in these simulations, as fol-ows:

. Temperature: 303 K

. Wind speed (at 10 m above ground): 1.6 m/s

. Wind direction: south to north

. RH: 84%

. Roughness length in 10 m: 0.1

. Total simulation: 24 h

. Results and discussions

.1. Quantifying greenery area of NUS Master Plan 2005

Fig. 8 shows the 11 zones of greenery division in NUS Masterlan 2005. It can be seen there are major changes and develop-ents in zone 1 (UCC and OED), zone 2 (SRC), zone 3 (SDE

nd Engineering), zone 4 (UH and YIH), zone 5 (Faculty ofcience), zone 6 (FASS and Law), zone 8 (Eusoff and Temasekall).In zone 1, the developments are some additional buildings

round University Cultural Centre and Office of Estate andevelopment. In this area, there will be a new access road to

he NUS Residential Colleges in Warren golf. In the sports area,one 2, three stories of new sports facilities will be built. Groundennis courts are designed to be above the rooftop of sport hallacilities. In the zone 3, SDE and Engineering, new buildinglusters will be built, removing most of the old Engineeringuildings, Raffles Hall and Visitor’s Lodge. New building clus-ers are planned along the Lower Kent Ridge Road in zones 4nd 5. It can be seen in the figure that large amount of greeneryill be removed. Temasek Hall and Eusoff Hall will be rebuilt
ith new building arrangement with radial concept. As part of
his master plan, currently NUS Alumni complex is under con-truction in zone 6. The Kent Ridge Guilt House will be rebuiltith the tennis courts on the rooftop.


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Fig. 7. Part of Faculty of Engineering

The calculated result in Fig. 9 shows the large green areaxists along the Kent Ridge Road in zone 7 over than 173,000 m2,

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ollowed by zone 4, close to 95,000 m . The ratio and propor-ion percentage are calculated in Table 1 and Fig. 10 to give alearer picture for the composition between the three elementsuilding, pavement and greenery in each zone. It shows that
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Fig. 8. Greenery zoning of N

r scenarios in ENVI-met simulation.

one 10—I2R has the largest greenery proportion, 1 m2 build-ng equals to 9.8 m2 of greenery, followed by zone 7—KE7,

2 2
MRE and SSLS, 1 m building equals to 6.9 m of greenery. Forhe building area proportion, zone 3—SDE and Engineering hashe largest building proportion, followed by zone 9, KRH andH.
US Master Plan 2005.


Fig. 9. Building–pavement–greenery area.

Table 1Building–pavement–greenery area and ratio of NUS Master Plan 2005

No. Zone name Area name Building area(m2)

Pavementarea (m2)

Greeneryarea (m2)

Ratio building:pavement:greenery

1 Zone 1 UCC and OED 35,701.68 31,705.65 39,370.06 1:0.89:1.12 Zone 2 SRC 44,789.70 24,967.98 86,297.01 1:0.56:1.933 Zone 3 SDE and Engineering 71,070.92 68.725.75 79,082.07 1:0.97:1.154 Zone 4 UH and YIH 28,369.70 37,601.46 94,955.56 1:1.33:3.355 Zone 5 Faculty of Science 49,631.09 43,854.81 69,043.15 1:0.88:1.396 Zone 6 FASS and Law 59,077.24 41,779.51 96,657.71 1:0.71:1.647 Zone 7 KE7, IMRE and SSLS 25,128.96 24,939.08 173,650.97 1:0.99:6.918 Zone 8 Eusoff and Temasek Hall 21,505.12 28,762.80 38,144.69 1:1.34:1.779 Zone 9 KRH and SH 8,077.39 7,948.63 8,194.27 1:0.98:1.0110 Zone 10 I2R 6,055.48 14,504.30 59,403.83 1:2.39:9.8111 Zone 11 PGP 12,640.20 25,612.35 36,523.59 1:2.03:2.89

Total (m2) 362,047.47 350,402.34 781,322.89Total NUS surface area (m2) 1,493,772.70

Fig. 10. Proportion of building–pavement–greenery area.


Table 2Building–pavement–greenery area and ratio of NUS Master Plan 2005

No. Zone name Area name Greenery area (m2) Total NUS surfacearea (m2)

Green rate = (greenery area/totalNUS surface area) (%)

1 Zone 1 UCC and OED 39,370.06 1,493,772.70 2.642 Zone 2 SRC 86,297.01 1,493,772.70 5.783 Zone 3 SDE and Engineering 79,082.07 1,493,772.70 5.294 Zone 4 UH and YIH 94,955.56 1,493.772 70 6.365 Zone 5 Faculty of Science 69,043.15 1,493,772.70 4.626 Zone 6 FASS and Law 96,657.71 1,493,772.70 6.477 Zone 7 KE7, IMRE and SSLS 173,650.97 1,493,772.70 11.628 Zone 8 Eusoff and Temasek Hall 38,144.69 1,493,772.70 2.559 Zone 9 KRH and SH 8,194.27 1,493,772.70 0.5510 Zone 10 I2R 59,403.83 1,493,772.70 3.981 .59

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otal (m2) 781,32

Green rate of NUS Master Plan 2005 was also calculatedo find which area has the largest area of greenery contributedotally to NUS campus. It can be seen from Table 2 and Fig. 11,one 7—KE7, IMRE and SSLS contributes 11.62% of green-ry from the total greenery area followed by zone 6, FASSnd Law of 6.47%. This green rate value will be more usefulfter the comparison with the NUS current condition in the nextection.

.2. Quantifying potential of rooftop greenery

As mentioned above, in this master plan, there will be a lot ofew buildings will be built. Therefore, it is very good opportunityo plan and design buildings with less impact to the environment,uch as buildings with rooftop garden.

The buildings in NUS Master Plan 2005 were categorizednto old and new buildings in order to quantify the potential
or rooftop greenery in new buildings, as seen in Fig. 12. Inable 3 shows that 8 of 11 zones have new buildings and 5 of 11ones have more than 50% of new buildings. For example, zone, Eusoff and Temasek Hall will have 100% new buildings. In
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Fig. 11. Green rate of NU

1,493,772.70 2.45

52.31

otal, it will be more than 56% is new buildings in this masterlan. Therefore, if these new buildings are really well plannedowards the environmental friendly, NUS environment will beetter.

In this study, three scenarios were made to analyze the poten-ial rooftop greenery on new buildings rooftop. They are 25%,0% and 75% of new buildings rooftop made available forooftop greenery. Designing a building with 75% of rooftop asooftop garden is possible with the mechanical system integra-ion, such as placement of cooling tower.

The results of three different scenarios are shown inables 4–6 for the rooftop garden application of 25%, 50% and5% rooftop on new buildings, respectively and Table 7 andig. 13 show the comparison of three different scenarios. For5% rooftop greenery application, the increase of green rate cane up to 3.41%, while for 50% rooftop greenery is up to 6.81%nd for 75% rooftop greenery can be as high as 10.22%. The
ighest increase of green rate is experienced in zone 3, SDE andngineering, as high as 2.43%. There are no changes in zone 9
KRH and SH), zone 10 (I2R) and zone 11 (PGP), since therere no new buildings in that area.

S Master Plan 2005.


Fig. 12. Building category of NUS Master Plan 2005.

Table 3Old and new buildings area of each zone

No. Zone name Area name Building area

Old (m2) Old (%) New (m2) New (%) Total

1 Zone 1 UCC and OED 21,182.37 59.33 14,519.31 40.67 35,701.682 Zone 2 SRC 1,656.38 3.70 43,133.40 96.30 44,789.703 Zone 3 SDE and Engineering 22,670.53 31.90 48,400.39 68.10 71,070.924 Zone 4 UH and YIH 9,462.19 33.35 18,907.51 66.65 28,369.705 Zone 5 Faculty of Science 24,615.58 49.60 25,015.52 50.40 49,631.096 Zone 6 FASS and Law 35,014.96 59.27 24,062.28 40.73 59,077.247 Zone 7 KE7, IMRE and SSLS 17,156.30 68.27 7,972.66 31.73 25,123.968 Zone 8 Eusoff and Temasek Hall 0.00 0.00 21,505.12 100.00 21,505.123 Zone 9 KRH and SH 8,877.39 100.00 0.00 0.00 8,077.3910 Zone 10 I2R 6,055.48 100.00 0.00 0.00 6,055.4811 Zone 11 PGP 12,640.20 100.00 0.00 0.00 12,640.20

Total (m2) 158,531.28 203,516.19 362,047.47

Table 4Application of rooftop greenery on 25% of new buildings rooftop

No. Zone name Area name Greeneryarea (m2)

25% Rooftop(m2)

Total newgreenery area(m2)

Total NUSsurface area(m2)

New green rate = (totalnew greenery area/totalNUS surface area) (%)

Increase ofgreen rate (%)

1 Zone 1 UCC and OED 39,370.06 3,623.83 42,999.88 1,493,772.70 2.88 0.242 Zone 2 SRC 86,297.01 10,783.35 97,080.36 1,493,772.70 6.50 0.723 Zone 3 SDE and Engineering 79,082.07 12,100.10 91,182.17 1,493,772.70 6.10 0.814 Zone 4 UH and YIH 94,955.56 4,726.88 99,682.43 1,493,772.70 667 0.325 Zone 5 Faculty of Science 69,043.15 6,253.83 75,297.02 1,493,772.70 5.04 0.426 Zone 6 FASS and Law 96,657.71 6,015.57 102,673.28 1,493,772.70 6.87 0.407 Zone 7 KE7, IMRE and SSLS 173,650.97 1,993.16 175,644.13 1,493,772.70 11.76 0.138 Zone 8 Eusoff and Temasek

Hall38,144.69 5,376.28 43,520.97 1,493,772.70 2.91 0.36

9 Zone 9 KRH and SH 3,194.27 0.00 8,194.27 1,493,772.70 0.55 0.0010 Zone 10 12R 59,403.83 0.00 59,403.83 1,493,772.70 3.98 0.0011 Zone 11 PGP 36,523.59 0.00 36,523.59 1,493,772.70 2.45 0.00

Total 781,322.89 50,879.05 832,201.94 55.71 3.41




50% Rooftop(m2)

Total newgreeneryarea (m2)




1 Zone 1 UCC and OED 39,370.06 7,259.66 46,629.71 1,493,772.70 3.12 0.492 Zone 2 SRC 86,297.01 21,566.70 107,863.71 1,493,772.70 7.22 1.443 Zone 3 SDE and Engineering 79,082.07 24,200.20 103,282 26 1,493,772.70 6.91 1.624 Zone 4 UH and YIH 94,955.56 9,453.76 104,409.31 1,493,772.70 6.99 0.635 Zone 5 Faculty of Science 69,043.15 12,507.76 81,550.90 1,493,772.70 5.46 0.846 Zone 6 FASS and Law 96,657.71 12,031.14 108,688.85 1,493,772.70 7.28 0.817 Zone 7 KE7, IMRE and SSLS 173,650.97 3,986.33 177,637 30 1,493,772.70 11.89 0.278 Zone 8 Eusoff and Temasek

Hall38,144.69 10,752.56 48,897.25 1,493,772.70 3.27 0.72

9 Zone 9 KRH and SH 8,194.27 0.00 8,194.27 1,493,772.70 0.55 0.0010 Zone 10 I2R 59,403.83 0.00 59,403.83 1,493,772.70 3.98 0.0011 Zone 11 PGP 36,523.59 0.00 36,523.59 1,493,772.70 2.45 0.00

Total 781,322.89 101,758.10 883,080.99 59.12 6.81



75% Rooftop(m2)

Total newgreenery area(m2)




1 Zone 1 UCC and OED 39,370.06 10.889.48 50,259.54 1,493,772.70 3.36 0.732 Zone 2 SRC 86,297.01 32,350.05 118,647.06 1,493,772.70 7.94 2.173 Zone 3 SDE and Engineering 79,082.07 36,300.29 115,382.36 1,493,772.70 7.72 2.434 Zone 4 UH and YIH 94,955.56 14.180.63 109,136.19 1,493,772.70 7.31 0.955 Zone 5 Faculty of Science 69,043.15 18,761.64 87,804.78 1,493,772.70 5.88 1.266 Zone 6 FASS and Law 96,657.71 18,046.71 114,704.42 1,493,772.70 7.68 1.217 Zone 7 KE7, IMRE and SSLS 173,650.97 5,979.49 179,630.46 1,493,772.70 12.03 0.408 Zone 8 Eusoff and Temasek

Hall38,144.69 16,128.84 54,273.53 1,493,772.70 3.63 1.08

9 Zone 9 KRH and SH 8,194.27 0.00 8,194.27 1,493,772.70 0.55 0.0010 Zone 10 I2R 59,403.83 0.00 59,403.83 1,493,772.70 3.98 0.0011 Zone 11 PGP 36,523.59 0.00 36,523.59 1,493,772.70 2.45 0.00

Total 781,322.89 152,637.15 933,960.04 62.52 10.22

Table 7Comparison of ratio building–pavement–greenery

No. Zone name Area name Ratio building:pavement:greenery

Initial design 25% of rooftop 50% of rooftop 75% of rooftop

1 Zone 1 UCC and OED 1:0.89:1.1 1:0.89:1.2 1:0.89:1.31 1:0.89:1.412 Zone 2 SRC 1:0.56:1.93 1:0.56:1:2.16 1:0.56:2.41 1:0.56:2.653 Zone 3 SDE and Engineering 1:0.97:1.15 1:0.97:1.28 1:0.97:1.45 1:0.97:1.624 Zone 4 UH and YIH 1:1.33:3.35 1:1.33:3.51 1:1.33:3.68 1:1.33:3.855 Zone 5 Faculty of Science 1:0.88:1.39 1:0.88:1:1.53 1:0.88:1.65 1:0.88:1.776 Zone 6 FASS and Law 1:0.71:1.64 1:0.71:1.74 1:0.71:1.84 1:0.71:1.947 Zone 7 KE7, IMRE and SSLS 1:0.99:6.91 1:0.99:6.99 1:0.99:7.07 1:0.99:7.158 Zone 8 Eusoff and Temasek Hall 1:1.34:1.77 1:1.34:2.02 1:1.34:2.27 1:1.34:1.529 Zone 9 KRH and SH 1:0.98:1.01 1:0.98:1.01 1:0.98:1.01 1:0.98:1.01

1 9.811 2.89

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0 Zone 10 I2R 1:2.39:1 Zone 11 PGP 1:2.03:

By looking at the increase of green rate, the priority of rooftopreenery application in new buildings can be given to the largestooftop area available. It can be summarized in sequence asollows:

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1:2.39:9.81 1:2.39:9.81 1:2.39:9.811:2.03:2.89 1:2.03:2.89 1:2.03:2.89

. Zone 3: SDE and Faculty of Engineering

. Zone 5: Faculty of Science

. Zone 6: FASS and Law

. Zone 8: Eusoff Hall and Temasek Hall


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Fig. 13. Comparison of three different sc

. Zone 4: UH and YIH

. Zone 1: UCC and OED

. Zone 7: KE7, IMRE and SSLS

The zone 2 (SRC) even shows as the second highest of greenate increase, it is excluded from the priority list. It is becauseost of the rooftop areas will be used as tennis courts and

wimming pools.The priority list is very useful for budgeting purpose. It is

ecause based on the life cycle cost study rooftop application iningapore (Wong et al., 2003), rooftop greenery application hasigh initial cost. However, it is observed that life cycle costs ofxtensive green roofs with or without consideration for energy
ost, are lower than that of exposed roofs. A study by Nationalarks (NParks and CTBP, 2002) shows that the extensive roofn its own could potentially replace the roof insulation layer.here is a 8.5% life cycle cost savings, with a payback period
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able 8omparison of building–pavement–greenery percentage between current condition a

o. Zone name Area name Currentcondition

Master pla2005

Buildingpercentage

Buildingpercentage

1 Zone 1 UCC and OED 25.83 33.442 Zone 2 SRC 8.57 28.703 Zone 3 SDE and Engineering 28.01 32.474 Zone 4 UH and YIH 13.30 17.635 Zone 5 Faculty of Science 36.48 30.546 Zone 6 FASS and Law 24.11 29.917 Zone 7 KE7, IMRE and SSLS 10.13 11.238 Zone 8 Eusoff and Temasek

Hall11.56 24.32

9 Zone 9 KRH and SH 31.10 31 100 Zone 10 I2R 9.02 7.571 Zone 11 PGP 23.49 23.49

os of rooftop greenery in new buildings.

f 10 years. That is, the cost savings will be sufficient to covernitial capital investment in 10 years.

.3. Evaluation on NUS Master Plan 2005—comparisonith NUS current condition

Comparison of building–pavement–greenery percentageetween current condition and NUS Master Plan 2005 was madeo find the significant changes in terms of reduction in greeneryrea. The results are shown in Table 8 and Fig. 14.

From the table, it can be seen that the most significant reduc-ion in greenery is at zone 4 (UH and YIH) from 80.8% to 59%.here are also reductions of greenery area in some zones, such
s in Zone 1 (UCC and OED) from 41.77% to 36.87%, zone 2SRC) from 57.25% to 55.3% and zone 3 (SDE and Engineer-ng) from 43.27% to 36.13%. These reductions are mainly dueo building developments in those areas.
nd NUS Master Plan 2005

n Currentcondition

Master Plan2005

Currentcondition

Master plan2005

Pavementpercentage

Pavementpercentage

Greenerypercentage

Greenerypercentage

32.39 29.69 41.77 36.8734.13 16.00 57.26 55.3028.71 31.40 43.27 36.135.86 23.37 80.84 59.01

20.66 26.98 42.86 42.4829.49 21.15 46.40 48.9416.84 11.15 73.03 77.6231.99 32.53 56.45 43.14

58.49 30.57 10.41 33.8316.20 18.14 74.78 74.2939.14 27.66 37.37 48.84


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Fig. 14. Comparison of building–pavement–greenery perc

In contrary, some areas increase their greenery area, such asn zone 7 (KE7, IMRE and SSLS) from 73.03% to 77.62%. Thiss mainly due to demolishing some small houses and reductionhe area of King Edward VII Hall (KE7). In zone 9 (KRH andH) and zone 11 (PGP) also increases the greenery area from0.41% to 33.83% and from 37.37% to 48.84%, respectively.t is mainly because the reduction of pavement area, convertinghe hard pavement area between building with grass and plants.t is a good practice which can be adopted for the other zones,or example, in zone 3 (SDE and Engineering) where pavementsre built between the buildings canyon.

The green rate between current condition and NUS Masterlan 2005 were also compared. The result can be seen in Table 9nd Fig. 15. It is similar with the previous analysis that in some
ones there are reduction in green rate due to the new buildingsevelopments, such as in zone 1, zone 2, zone 3, zone 4, zoneand zone 10. In total, the green rate is reduced from 55.1% to2.31%. From the environment sustainability point of view, it is
somg

able 9omparison of green rate between current condition and NUS Master Plan 2005

o. Zone name Area name CGN

Zone 1 UCC and OEDZone 2 SRCZone 3 SDE and EngineeringZone 4 UH and YIHZone 5 Faculty of ScienceZone 6 FASS and LawZone 7 KE7, IMRE and SSLS 1Zone 8 Eusoff and Temasek HallZone 9 KRH and SH

0 Zone 10 I2R1 Zone 11 PGP

otal (m2) 5

e between current condition and NUS Master Plan 2005.

ot good to have this reduction. Therefore, planning should beade to improve the greenery condition.Along with the previous analysis, one of the methods to

ncrease green rate is application of rooftop garden. The com-arison chart can be seen in Fig. 16. In general, by applyinghis rooftop greenery can improve the green rate. In particular,n order to improve the green rate to be at least similar to theurrent condition, different scenario of rooftop greenery may bemployed. For example, in zone 1 (UCC and OED), by applyingnly 25% area of new buildings rooftop into rooftop garden, itan have similar green rate with current condition. But, in zone(SDE and Engineering) in order to have similar green rateith previous one; it should convert 50% area of new buildings

ooftop into rooftop garden. In zone 2 (SRC), in order to have
imilar green rate with previous one; it should convert 75% areaf new buildings rooftop into rooftop garden. For this zone, itay not be reasonable to convert 75% its rooftop into rooftop
arden, since the rooftop will be mainly used for tennis courts

urrent condition Master Plan 2005reen rate = (greenery area/totalUS surface area) (%)

Green rate = (greenery area/totalNUS surface area) (%)

2.81 2.647.09 5.786.58 5.297.73 6.364.22 4.626.22 6.470.75 11.623.53 2.550.18 0.554.37 3.981.64 2.45

5.10 52.31


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Fig. 15. Comparison of green rate between

nd swimming pools. Also in zone 4 (UH and YIH), even apply-ng 75% its rooftop into rooftop garden, it may not have theimilar green rate as current condition due to large new build-ng developments. For these two zones, application of verticalreenery may be of very useful to increase the green rate.

.4. Temperature prediction on NUS Master Plan 2005

In the first analysis, the ENVI-met simulation results of
US Master Plan 2005-as designed and NUS Master Plan005-increased trees were compared with the result of currentondition. The graphical data of three different scenarios wererocessed to be in the same range to get a fair comparison.
Fmin

ig. 16. Comparison of green rate between current condition, NUS Master Plan 200ooftop garden application.

ent condition and NUS Master Plan 2005.

Fig. 17 shows the daytime ambient temperature comparison.t is clearly seen that the ambient temperature of NUS Masterlan 2005 is much higher than the current condition. The dif-erence is about 1 ◦C. This is due to the reduction of greeneryrea. It is the same as for the nighttime ambient temperature inig. 18. Even the dense greenery area along Kent Ridge Road hasore significant impact, but the ambient temperatures around the

uildings remain high, the urban heat island phenomena happen.Putting more trees for NUS Master Plan 2005 during daytime,

ig. 17, as compared with current condition is still higher. Evenore yellowish color starts to appear around the building. The

mpact of the increase of greenery is very significant during theighttime, as in Fig. 18. The condition is better as compared with

5, 25% rooftop garden application, 50% rooftop garden application and 75%


Fig. 17. Comparison of ENVI-met results with current conditions—daytime.

Fig. 18. Comparison of ENVI-met results with current conditions—nighttime.


Fig. 19. Comparison between NUS Master Plan as designed with increased trees—daytime.

Fig. 20. Comparison between NUS Master Plan as designed with increased trees—nighttime.

Fig. 21. Comparison of four scenarios in part of Faculty of Engineering.

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N.H. Wong, S.K. Jusuf / Landscape

he current condition. Green and blue colors appear between theuildings as the result of a lower ambient temperature due to theresence of greenery.

It can be concluded that the presence of greenery is one ofhe methods to make the NUS Master Plan 2005 better. A moreignificant amount of greenery should be added.

In addition to the previous analysis, the comparison onlyetween the NUS Master Plan 2005-as designed and NUS Mas-er Plan 2005-increased trees was made. To get a more detailomparison, some color scale adjustments were made.

Figs. 19 and 20 show that greenery really makes the ambientemperature cooler. The “hot spots” which initially occur nearaculty of Engineering, University Cultural Centre and sportentre have now become much cooler as a result of coolingffects of much denser greenery in centre region of NUS andther areas. It can be derived also the knowledge that plantingreenery distributed around the complex has more impact ratherhan only concentrated in a particular area.

The new building clusters in Faculty of Engineering becomeart of the interest because it is designed with closed build-ngs arrangement and pedestrian pavements. It is expected thathe heat will be trapped in the buildings and released duringighttime.

Fig. 21 is the nighttime ambient temperature comparison. Ithows that heat is built up between buildings in the “as designed”cenario. Planting of grass on the rooftop has impact to the envi-onment, it is because grass prevents the heat enters the buildinguring daytime and then during the nighttime, there is not mucheat released to the environment. Therefore, the environmentecomes much colder.

Planting trees on rooftop even has more impact, because it isot only prevent heat enters the buildings but also has the coolingffect due to the evapotranspiration process. In order to make theooling effect become greater, it is suggested to plant trees on theround to give more benefit for the human activities. The higherhe Leaf Area Index (LAI) in an area, the more pronounced itsooling effect.

. Conclusion

The building–pavement–greenery proportion was quantifiedor the NUS Master Plan 2005. There are major developmentsound in zone 1 (UCC and OED), zone 2 (SRC), zone 3 (SDE andngineering), zone 4 (UH and YIH), zone 5 (Faculty of Science),one 6 (FASS and Law), zone 8 (Eusoff and Temasek Hall). Thereen rate of NUS Master Plan 2005 is 52.31% reduced from5.1%.

As there will be more than 56% of new buildings built inUS campus, therefore it is very useful to plan and design theseew buildings with rooftop greenery to increase the green ratef NUS Master Plan 2005. Three scenarios were employed tonalyze the rooftop garden potentials. They are 25% rooftoparden application, 50% rooftop garden application and 75%
ooftop garden application. Based on the calculated area, thesepplications may be considered as one of the methods to improvehe NUS Master Plan 2005 green rate become at least similarith current condition or better.
S

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rban Planning 84 (2008) 166–182 181

However, in some locations application of 75% rooftop areas rooftop garden may not be sufficient or not reasonable tochieve similar green rate, for example, in zone 4 (UH and YIH)nd zone 2 (SRC). Therefore application of vertical greeneryan be considered to increase the greenery area.

The ENVI-met simulation predicts that the ambient temper-ture in NUS environment will increase about 1 ◦C when NUSaster Plan 2005 is completed. It is due to the reduction of

reenery rate from 55.1% in the current condition to 52.31%.he bare pavements between buildings without any greenerylso contribute to the increase of ambient temperature.

Planting grass can prevent heat enters the building. A greatermpact can be given by planting trees on the rooftop, becauset gives the cooling effect due to evapotranspiration process.lanting more trees at the human occupancy level will give moreenefits in reducing the ambient temperature.

cknowledgement

This research is supported by Department of Building,ational University of Singapore. I would like to send my great

ppreciation to Office of Estate and Development, especiallyor Ms. Lina Goh and Mdm. Helen Yip in providing all of theupporting data.

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gis-based greenery evaluation on campus master plan

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