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MORPHOLOGICAL AND PHYSIOLOGICAL ANALYSIS

OF URBAN ENVIRONMENT

Case Study: A Singapore New Town

BY

FAYSAL KABIR SHUVO

This book is based on the dissertation submitted for the partial fulfillment of

the requirements for Masters of Science in Environmental Management at

National University of Singapore



Dedication

This book is fully dedicated to my loving wife Farzana Afrin Tani

Faysal Kabir Shuvo

Singapore

22/06/2010



Morphological and Physiological Analysis for Measuring Urban Environmental

Performance: A Case Study of Bukit Panjang New Town

I

Acknowledgement

In the beginning, all praises belong to almighty Allah, the most kindhearted and the most

merciful to man and his actions, which provides me the opportunity to complete this study

successfully.

I wish to express my most sincere and profound gratitude to my dissertation supervisor

Dr. Perry Yang, former Assistant Professor, Department of Architecture, NUS, for his

constant supervision and encouragement, valuable advice and comments which had been

very much conducive in carrying out this research. I also feel his affectionate but

disciplined guidance has allowed me to reach my destination. My heartiest gratefulnessshould be for two famous Professor Emeritus of Urban Design, ETH Zurich, Franz

Oswald and Peter Baccini as well as Senior lecturer, Mark Michaeli for their

wholehearted cooperation in getting familiar with various terms of ‘Netzstadt’.

My deep gratitude also goes to Dr. Simon Yanuar Putra for his dedicated and benevolent

cooperation in making me familiar with ArcGIS and sometimes with sharing knowledge

of difficult design terms, I am really grateful to him. In same connection I am also owe to

Gunawan Tanuwidjaja, MEM graduate, Dr. Asim Kumar Debanath, Dr. Steve Cardinal

Jusuf, for their helps in various technical issues.

I recall the supports with warm appreciation and great regards, which were extended by

the various personnel of Singapore Land Authority, Urban Redevelopment Authority,

Singapore Power, and Building Construction Authority by providing me useful data for

carrying out the research.

Finally, we are grateful and humbly acknowledge that this work could not have been

completed without the moral support of our families.





II

Preface

The term ‘sustainability’ is given enormous momentum over the past few decades for

ensuring a vigorous living condition for the future generation which mostly has been

concentrated on the economic freedom and social equity while leaving the ‘environment’

issues apart; another important issue of sustainability. This environment is being

jeopardized with the pace of constant increasing rate of urbanization, giving birth to the

multiple environmental issues ranged from local like ‘urban heat island’ to global as

‘global climate change or global warming’. Policymakers, city planners and designers

therefore have recent given their deep attention to sustainable urbanization or urban form

which starts with individual buildings and deals up to city scale. For planning and

subsequent designing of a sustainable urban form require a finer scale environmental

performance analysis of what already built. Urban environment depends on the shape and

organization of spaces (morphology) on one side as well as on the physical resource

management and flow (physical process) within the built environment on the other hand

which are mainly anthropogenic modifications of the arrangements and orientations of the

environment. So a set of indicators are needed for an effective analysis of existing

environment to guide planning and designing of a potential urban area. Modern

geographic information technologies like GIS, remote sensing with diverse statistical

tools like MS Excel, SPSS, SAS, STATA have made it easy to a large extent to reach a

multiple objected decision making regarding urban environment. In this study, an

environmental performance analysis has been performed based on multiple morphological

and physiological indicators for Bukit Panjang, a new town of Singapore. Though

Singapore government is much vigilant in urban planning in terms of ecological and green

coverage perspectives, how the morphological properties like building density (plot ratio),

subdivision of land parcels, urban grain sizes and level of accessibility of land parcel are

correlated with the physiological process like material intensity and electricity use is still

unexplored. In this research an effort is made to make up the previous study gap; better to

say that the author hopes at least that the study approach will pave a nice way further

research in urban environmental performance analysis towards sustainable urban form.





III

The contents of this book are organized into eight chapters. The first chapter

includes mainly the background and purposes of the research based on which the base

thesis was done. The second chapter has summarized the literatures relevant to the

research issues like sustainability of built environment and the performance indicators of

urban built environment based on the morphological and physiological characteristics.

The methodology of the whole research is described in the chapter three, followed by a

short description of the study area in the chapter four. Chapter five includes the concept of

urban environment, the morphological and physiological indicators pertinent to analyze

the performance of urban environment. Chapter six described the GIS based analysis of

the indicators developed at the earlier chapter; the correlation analysis among the

indicators is also described in this chapter. Chapter seven incorporates the proposed

recommendation following the analysis result and chapter seven is followed by the

concluding chapter eight.





IV

Table of Contents

Title Page No.

ACKNOWLEDGEMENT I

PREFACE II

TABLE OF CONTENTS IV

LIST OF TABLES VI

LIST OF FIGURES VI

LIST OF MAPS VI

ACRONYMS VII

CHAPTER 1: INTRODUCTION AND BACKGROUND

1.1 Introduction 1-1

1.2 Motivation of the Study 1-2

1.3 Objectives of the study 1-3

1.4 Scopes of the Study 1-3

1.5 Research Questions and Hypothesis 1-4

1.6 Limitations 1-5

CHAPTER 2: LITERATURE REVIEW

2.1 Emergence of the issue of Sustainability 2-1

2.2 Sustainable Urban Form 2-2

2.3 Environmental Performance of the Built Environment 2-3

2.4 Sustainability Indicators of Urban form 2-4

2.4.1 Working with the morphological indicators 2-4

2.4.2 Working with the physiological indicators 2-11

2.5 Multi scale assessment of environmental performance and GIS 2-15

2.6 Knowledge Gap 2-18





V

CHAPTER 3: METHODOLOGICAL FRAMEWORK

3.1 Selection of the Study Area 3-1

3.2 Collection of Necessary Maps 3-1

3.3 Literature Survey 3-1

3.4 Identification and Principles of the Indicators 3-2

3.5 Collection and Compilation of the data and information 3-3

3.6 Calculation of the Indicators 3-3

3.7 Analysis and Visualization of the results 3-6

3.8 Proposal and Recommendations 3-6

CHAPTER 4: STUDY AREA

4.1 History and Location 4-1

4.2 Profile of the Study Area 4-1

CHAPTER 5: PROPOSED INDICATORS FOR ENVIRONMENTAL ANALYSIS OF

BUKIT PANJANG

5.1 Urban Environmental Performance 5-1

5.2 Morphological Indicators 5-2

5.3 Physiological Indicators 5-9

CHAPTER 6: ANALYSIS OF INDICATORS AND FINDINGS

6.1 Morphological Indicators 6-5

6.2 Physiological Indicators 6-16

6.3 Correlation and Multiple Linear Regression Analysis 6-21

6.4 Discussion 6-25

CHAPTER 7: RECOMMENDING PROPOSAL 7-1

CHAPTER 8: CONCLUSION 8-1

REFERENCES Ref-1





VI

List of Tables

Title Page No.

Table 5.1: Material Stock in Bukit Panjang from 1993-2005 5-11

Table 5.2: Average Household area of various building typologies in Singapore 5-13

Table 5.3: Average Electricity Consumption for all households

of the same house type 5-13

Table 5.4: SLA defined building types 5-13

Table 5.5: Calculated Electricity Use Intensity for Built Structures

in Bukit Panjang 5-15

Table 6.1: Existing Characteristics of the Building typologies in Bukit Panjang 6-1

Table 6.2: Status of the Built Environment Data in Bukit Panjang 6-2

Table 6.3: Pearson Correlation Coefficients for two sets of Indicators 6-23

List of Figures

Title Page No.

Figure 3.1: Methodological Framework 3-7

Figure 6.1: Share of Built and Non-built area 6-1

List of Maps

Title Page No.

Map 4.1: Singapore Map 4-3

Map 4.2: Map of Study Area (Bukit Panjang) 4-3

Map 6.1: Building Density of Bukit Panjang New Town 6-3





VII

Map 6.2: Building Status in Bukit Panjang New Town 6-4

Map 6.3: Topography of Plot Ratio in Bukit Panjang 6-6

Map 6.4: Plot Ratio Density in Bukit Panjang 6-7

Map 6.5: Subdivisions of Land Parcels in Bukit Panjang 6-9

Map 6.6: Degree of Subdivision in Bukit Panjang 6-10

Map 6.7: Granular Index of Built Environment in Bukit Panjang 6-12

Map 6.8: Density Map for Level of Accessibility 6-14

Map 6.9: Topographical Representation for Level of Accessibility 6-15

Map 6.10: Density of Still (kg) in Bukit Panjang Buildings 6-17

Map 6.11: Density of Cement (kg) in Bukit Panjang Buildings 6-18

Map 6.12: Density of Coarse Aggregate (kg) in Bukit Panjang Buildings 6-19

Map 6.13: Density of Fine Aggregate (kg) in Bukit Panjang Buildings 6-20

Map 6.14: Electricity Use Intensity (kWh/m2) of Bukit Panjang 6-22

Acronyms

GIS Geographic Information System

IT Information Technology

IUCN International Union for Conservation of Nature

WCED World Commission on Environment and Development

EPA Environmental Protection Agency

GHG Green House Gas

CIAT Chartered Institute of Architectural Technologists

USA United States of America





VIII

ULM Urban Landscape Model

EU European Union

LT Lighting and Thermal

NUS National University of Singapore

SLA Singapore Land Authority

URA Urban Redevelopment Authority

BCA Building Construction Authority

HDB Housing Development Board

MND Ministry of National Development

MRT Mass Rapid Transit

LRT Light Rail Transit

SP Singapore Power

GDP Gross Domestic Product



Introduction 1-1

Chapter 1

Introduction and Background

1.1 Introduction

When we note the term “Sustainable Development” or “Sustainability”, most of the

experts try to link between economics and environment. However, urban areas are key

objects for sustainable planning in terms of physical development of a country or region.

Urban system is centered in urban areas that are morphologically modified by the men

and in terms of ecosystem services, urban areas are primarily sites of consumption, use

and generating wastes, which are termed as ‘urban metabolism’ (outcome of physiological

processes). Urban areas are the major elements of the modern landscapes, and as such are

impacted by and are sources of significant ecological changes and landscapes

fragmentation (Perry, 2007). The urbanization process converts the vegetated landscapes

into fragmented building covers made of asphalt and concrete. These changes in nature of

landscapes (anthropogenic modification of urban morphology) have primarily affected

solar reflectivity, evaporative efficiency, and roughness of surface therefore

anthropogenic energy flows have come to an important role (i.e. electricity) through it.

Energy is necessarily required for various activities in urban ecosystem and it comes from

various sources. Energy has very vital implications in various activities (physiology of

city) in urban areas which in turn determine the urban morphology or vice versa.

Not only does the consumption of non-renewable resources deplete the world’s finite

material and energy stocks upon which economic and social development depend, but the

use of both renewable and non-renewable resources cause environmental degradation

during transportation, storage, processing and disposal (Guy et.al, 2001). The demands

for high energy consumption in modern industrialized cities are usually filled through

electricity and combustion of oil, gases and coal which ultimately produce another kind of

waste energy flow named ‘heat’. This phenomenon is popularly known as “Urban Heat



Introduction 1-2

Island (UHI)”. UHI is largely dependent on the urban form that determines the

physiological processes like energy flow and material flow etc within the urban

environment. Therefore needless to say that to understand the sustainability of any urban

environment there are an acute need to analyze the morphological and physiological

characteristics of the urban system.

1.2 Motivation of this Study

The motivation behind this work is to put emphasis on the significance of scientific

knowledge in evidence-based policy-making for sustainable development. The book

contents come within the scopes of the built environment and energy and material

consumption (flow) which is incorporated into the GIS as the principle interface for data

input, storage, retrieval, and manipulation. With the help of advanced IT capacity, further

various geo-process functions of queries, mapping, modeling, visualization and spatial

analysis have been carried out which is highly useful for the environmental decision

making space. The famous book of Oswald and Baccini (2003) named ‘Netzstadt’-

German word which means the ‘The Network of City’ has motivated a lot to carry out the

research. In fact, few indicators, terms and processes used in this thesis are mostly

replicated from the book.

It is known that the provision of electricity (physiological character) in cities is one of the

main drivers for sustainability, which helps to trade off the availability of natural

ventilation and natural light. Steemer (2003) notes that the energy and environmental

implications of buildings are much more significant than that for transport; however,

transport issues receive greater political attention as there is a stronger connection of local

pollution to cars; and because cars are associated with other issues, such as accidents and

social impacts. Given the effects of urban form on electricity consumption, it is highly

advisable to look at the particular unit of urban environment as a whole. However, the

majority of past studies mainly focused on individual buildings which not only limit the

progress towards sustainability, but also have the opposite effect on the building itself and

adjacent environments as well.



Introduction 1-3

This work is the author’s dissertation to fulfill the requirement of Masters of Science in

Environmental Management and aimed at formulating a correlation between urban form

and anthropogenic physical flows, specifically the issues of electricity consumption to

investigate their mutual influence over each other at the neighborhood blocks with the

ultimate aim to help the urban policy-makers and practitioners.

1.3 Objectives of the Study

Every research is ascertained to achieve few objectives. This study has also a set of

objectives to be achieved, they are to

- assess the selected morphological indicators for the study area

- identify very simple physiological behavior of the area

- see the correlation between two sets of indicators, and

- draw conclusion based on the two sets analysis for future urban

planning of Singapore.

1.4 Scopes of the Study

While sustainability is a prevailing issue in every kind of development, let alone the urban

development which is supposed to be the base of all other type of developments e.g.

infrastructures, industries, land development etc; therefore, sustainable urban development

requires transdisciplinary actions. Various disciplines like architecture, engineering,

natural science involved in this analysis could be able to address the specific problems

emerged from urban planning tasks. The long term objectives of these multi-criteria

analyses of urban environment may accomplish various aspects of whole urban system

e.g. to develop urban form or whole of the territories, the allowable metabolism for the

global and regional conditions, integration of other disciplines like social sciences,

economics, politics, anthropology as well as understanding of the whole urban system

processes like norms, institutions and technical infrastructures. When evaluating

environmental performance based on multi criteria analysis, electricity consumption as

energy flow has been considered. Though in small scale, the inclusion of energy in



Introduction 1-4

assessing environmental performance will bring a good result for energy efficiency for

various uses in urban areas for sustaining urban form.

1.5 Research Questions and Hypothesis

In the research following research questions are to be address:

1. On what components and elements the quality of an urban system depends and

how they are described, analyzed and visualized?

2. What tools are available to analyze urban environment? and

3. How the sustainable urban planning and design is governed by the

morphological and physiological analysis of an urban environment.

To address the above questions and from literature review some hypothesis were needed

to be tested. The testable hypotheses are as follows:

1. The urban environment depends on both its morphology e.g. arrangement of the

environmental fields and physiology e.g. the management, flow and consumption

of the resources.

2. Urban system is merely seen as a hierarchical arrangement rather than network

of nodes where high density of population and flow of energy and goods are

marked.

3. Urban system has three distinct elements namely nodes, connecting network

between nodes and a visible or empirical boarder.

4. Consumption of electricity varied from households to households is the

principal source of energy flows through urban system and material flow due to



Introduction 1-5

infrastructure and building constructions are considered the main material flow

through the urban environment for metabolism.

Apart from the above generalized hypotheses, hypotheses are made for analyzing various

indicators based on those depicted mainly in ‘Netzstadt’1

in subsequent chapters.

1.6 Limitations

Multifold limitations have been faced during carrying out the research, data collection and

data analysis. Firstly, an urban scale research is very time and resource consuming which

restricted the author to go in depth to analyze scenario. Use of GIS tools, the most

sophisticated software packages is costly therefore had to manage the GIS operation and

analysis in combined computer lab. Limitations also have been faced in the collected data

from the only land information provider agency (SLA) in Singapore; mismatches of shape

files in various layers were found which further impeded fine analysis. Again various

spatial data is not available to any single agency. For example building heights, landuse

data were not available to Singapore Land Authority (SLA) for which needed to contact

with Urban Redevelopment Authority (URA). Mismatches were found also in their data

i.e. in SLA data it is shown no building in some lots where as in URA data a particular

plot ratio is assigned for the buildings. To overcome with these type difficulties needed

extensive fieldworks, which are again self-supported, after all within such a short time

such an analysis with huge data volume is really much tedious.

1Oswald, F., & Baccini, P., in association with Michaeli, M. (2003) “ Netzstadt – Designing the Urban”.

Switzerland: Birkhauser.



Literature Review 2-1

Chapter 2

Literature Review

The principal components of this research are built on the sustainability of urban

environment and tools (morphological and physiological here in this research) for

analyzing urban environment to ensure sustainable urban planning and design. Therefore,

during literatures reviews from various resources, concentration is given put on the

relevant topics of sustainability, spatial and physical characteristics of city and built

environment, application of GIS in analysis etc.

2.1 Emergence of the issue of Sustainability

The Stockholm Environmental Conference of the United Nations (1972) was the first

major meeting of the international community to express grave concern over the

deteriorating environment (Hamm & Muttagi, 1998 p.1). At this conference 113 nations

pledged to begin cleaning up the environment and most importantly to begin the process

of tackling environmental issues on a global scale.

The combined term sustainable development was coined in the “World Conservation

Strategy” of the IUCN in 1980 (Huber, 1995), but it never gained paradigmatic appeal

before its use and interpretation in the WCED report. Since then, in addition to its political

impact, the term rapidly became a new research paradigm in a wide range of disciplines,

from the social sciences to biology (Becker, 1997).

The etymological roots of sustainability as a derivation from the Latin verb sustenere (=

uphold) (Redclift, 1994). This etymology is also reflected in the debate among Spanish-

speaking scientists; that is, whether sostenibilidad (from sostener ) or sustentabilidad

(from sustentar ) is the more accurate translation (Becker, 1997). The first term is closer to

the passive connotation of “being upheld,” while the latter reflects more the active aspect

of “to uphold.”




These considerations of terminology indicate that there is a strong normative component

in the concept of sustainable development. This value-driven normative aspect makes

sustainable development attractive for policymakers because it permits a direct translation

of political objectives into a broadly agreed overall concept (Becker, 1997).

Sustainability has come from a global political process that has tried to bring together,

simultaneously, the most powerful needs of the current decade:

the need for economic development to overcome poverty,

the need for environmental protection upon which we all ultimately depend, and

the need for social equity to enable local communities to express their values in

solving these issues.

Thus when the issue of sustainability is referred, it will be the simple idea that means the

simultaneous achievement of social, economic and environmental sustainability.

However, in my study the prime focus is on the environmental sustainability and its

consequences.

2.2 Sustainable Urban form

The emergence of “sustainable development” as a popular concept has received the

enormous discussions about the form of cities (Jabareen, 2004). The urban form directlyaffects habitat, ecosystems, endangered species, and water quality through land

consumption, habitat fragmentation, and replacement of natural cover with impervious

surfaces or surface sealing (EPA, 2001). Urban form also induces or reduces the length of

automobile travel, helps choosing mode of travel which ultimately affects the urban

environment.

In searching sustainable urban form we should try to answer- to what extent and in what

ways does urban form contribute to sustainability? Ideally sustainable urban form is the

orientation and arrangement of building clusters, their densities and layout, road

infrastructures and other physical infrastructures that would ensure:

- Environmental sustainability

- Social sustainability

- Economic sustainability




While sustainable development is to be ensured, the contemporary urban planners and

policy makers are on brain storming debates to find out the sustainable urban form so that

above mentioned three sustainability indicators can be ensured in various scales namely

regional, city, neighborhood and individual building level. In this regard, traditional urban

planners or designers attention has been more diverted to resource optimizing andefficient city or town planning.

The outcome from this debate, particularly in Europe, the USA and Australia was a strong

advocacy of the ‘compact city’ model. Essentially this is a high-density, mixed-use city,

with clear (i.e. non-sprawling) boundaries (Jenks et al., 1996; Williams et al., 2000).

Jabareen (2006) identified seven concepts for designing Sustainable Urban Form; they are

i) Compactness, ii) Sustainable Transport, iii) Density, iv) Mixed Land Uses, v) Diversity,

vi) Passive Solar Design and vii) Greening.

2.3 Environmental Performance of the Built Environment

The popularization of Sustainable Development has contributed to the promotion of the

urban compactness idea by enhancing the ecological and environmental justification

behind it (Yosef, 2006). It is believed that compact city is prescribed for its environmental

advantages. Less road networks, connected mixed used buildings with planned parks,

green areas and other landscaping provide sufficient greenery that has good environmental

effect on the surface sealed land cover i.e. buildings, courtyards, parking areas and streets.It is found that compact cities have an adverse environmental implication like the

generation of heat if the sufficient greenery and other environmental indicators are not

properly maintained.

Landscape plays an important psychological role in the urban areas and help to reduce the

effect of “urban heat island”, filters pollution, accommodates diverse wild life. Plants can

absorb noise and pollution. Urban landscape absorbs rain, reducing the discharge of urban

rainfall and storm water. As discussed earlier, compact city reduces the amount of travel

which in turn helps to generate more waste energy like CO2 and any other GHG. But

energy implication for buildings and other impervious surfaced structures are still

unknown for compact cities.




2.4 Sustainability Indicators of Urban form

The resource uses and environmental impacts of household consumptions are identified as

key aspects of sustainable development. Holden et al’s (2003) study also supports the

hypothesis that there is a connection between the characteristics of land uses andhousehold consumption of energy. Adolphe (2001) again found the conclusive evidence

of the influences of urban configuration on outdoor climatic conditions, on the energy

balance of buildings, and on diffusion of pollutants. The analysis of key indicators is

important for making decision about sustainable use and management of environmental

resources especially when environment is a dynamic concept. Indicators for the economic

and social development have already been developed and rigorously adopted. But

sustainable tools for assessing environmental development have been not yet discovered.

For assessing environmental performance we need to look for various environmental

indicators. Environmental indicators vary from scales to scales as we want to assess.

Typically air, water and land are considered the main component of an environment

therefore sustainability indicators are mainly based on the maintaining the quality of these

three components. On the other hand, indicators related to the arrangement of land and its

modification by people are considered as morphological indicators and the consumption,

process and management of air, water and other resources are related to physiological

indicators. In addition, when the issues of sustainable urban form arise, some relatively

new indicators come into discussion like material stock, energy flow, and green ratio.

2.4.1 Working with Morphological Indicators

Adolphe (2001) tried to obtain some generic behavior laws covering the complexity of

urban morphology and the variety of climatic conditions which have been put in a

substantial form through a scheme of morphological indicators which further had been

gone through a kind of rectification by a set of general criteria at the system level which

has been described in the paper as follows

(a) Completeness,

(b) No redundancy,

(c) Operationality,




At the indicator level, she has concentrated on the following criteria:

(1) Physical consistency, by looking for consistency of indicators with the physical

phenomena they are supposed to cope with;

(2) Spatial consistency, with indicators consistent with geographical (macroscopic) scale;

(3) Measurability, the availability of required data from common sources

(4) Legibility, with indicators easy to interpret;

(5) Comparability, by choosing indicators for which absolute values are not highly

significant, but for which relative variations (range and direction) are significant.

The hypothesis behind the selection of these set of indicator is as follows

The city is subjected to various interactive climatic considerations. This approach is

focused on the four most significant ones: wind, temperature, solar radiation (heat and

light), and humidity.

Adolphe’s model defined a set of indicators to measure the environmental performance of

urban fabrics: namely density, rugosity, porosity, sinuosity, occlusivity, compacity,

contiguity, solar admittance, and mineralization. This model has been embedded in a GIS

called Morphologic and applied to the analysis of existing urban fabric.

Applying the above indicators on three different urban areas i.e. a medieval neighborhood

in the center Toulouse (France), a suburban area predominant with detached house in

Blagnac (France), and a dense downtown area of Portland (USA) Adolphe summarized

the result as follows:




Building density: The lower building density (built area/total area ratio) prevails in the

suburban area, where it is four times lower than in a dense medieval fabric; in the US city,

the low footprint area of high-rise buildings is balanced by their height, but the density is

twice as low as in the European historic center.

Rugosity: The absolute rugosity which is the mean height of the urban canopy, variations

of which have been considered three times more important than those of mean building

height, because the area of non-built outdoor areas is used in the first calculation. Despite

large variations of the building height between a medieval fabric and a downtown district

in the United States, the absolute rugosity of the latter is only twice that of the first. The

comparisons between the three relative rugosity roses (defined as is the mean square

deviation of canopy height) give information about changes in the mean wind speed in a

given direction.

Porosity: The number of open `pores' in the urban canopy is significant in a high-rise

urban center, especially when compared with a dense medieval pattern but the comparison

with a suburban area with a high rate of non-built open spaces shows small variations

between them.

Sinuosity: This parameter characterizes the corridor effect of the street pattern. The author

put the example of the gridiron street pattern of Portland where the two perpendicular

directions corresponding to the street axis created a strong effect of wind canalization

(with sinuosity values close to zero, for a wide angle of distribution).

Occlusivity: The distributions of the built to non-built perimeter against height were found

varied widely between the different patterns. The medieval fabric corresponds to a high-

density city with relatively uniform building height, and can be related to a very narrow

mean sky-view angle when compared with the openness of the second pattern. The

suburban area has a low density and a wide distribution of the occlusivity ratio. The high-

rise pattern generates a narrow variation of the occlusivity factor with height.




Compacity: The analysis of compacity resulted in that the tall and isolated buildings

generate a low compacity. Contrastly, an established dense medieval fabric remains

insignificant (2.5 times) because the low height of each individual building (high exterior

area for the volume) is evened out by the high contiguity between buildings.

Contiguity: The author found the factor ‘contiguity’, which showed much variation (one

hundred times) between the US downtown and the medieval fabric. The high variations of

this parameter when compared to the low relative variations of the compacity factor show

the importance of using both parameters to qualify the geometry of buildings in an urban

pattern.

Solar admittance: The effect of shading neighboring buildings from sunlight is very

important with low and dense patterns such as the historic center. When compared with

suburban areas, there patterns can be seen to induce a lower solar admittance (less than

twice). Despite high and large glazed facades, a high-rise urban area suffers from mutual

shading between buildings.

Mineralization: Mineralization has been defined in this study as the presence of

substantial area covered with vegetation and water body which play significantly in

modifying local climate. The values of these indicators have been marked with very

slight variations between the three examples.

The indicators have been used in this research highly significant for small scale like

neighborhood level and it requires very complex data calculation (including various 3D

data), lot of metaphors have been used for these indicators so why seems very confusing

for beginner researcher. Particularly Adolphe’s research only concentrated on the

territorial arrangements but didn’t include the effects of these arrangements on the

physical consumption of the particular urban unit. It is also subject to further research

whether the indicators applicable for whole city scale.




In Urban Landscape Model (ULM) developed by Yoshida et.al (2005), the authors used

the six types of morphological properties, e.g. (1) surface area per projected area; (2)

volume per projected area; (3) building to land ratio; (4) mean height of buildings; (5)

surface area of buildings per unit volume of buildings; and, (6) mean volume of buildings

on city block wise over a study area sized of 2Km*2Km in Tokyo of Japan. In this study

remotely sensed LIDAR data has been used and converted into GIS platform to analyze

the selected properties on various types of residential, commercial and sub-urban blocks.

Yoshida et. al. expressed the first two properties by a featured space and represented as a

scattergram which is as follows:

For the third and forth properties the authors used two regulatory indicators namely BTL

(building to land ratio) and FAR (floor area ratio) which are shown by the following

histograms:




The fifth property named as surface area of buildings per unit volume of buildings has

been termed as ‘Compactness’ also. The compactness value found here according to the

calculating procedure depicted by the authors are different from the more conventional

compactness and it is called 3-dimensional compactness and the derivation of the formula

was as follows:

The variable, surface area per building volume was expressed as:

C = S/V

Where C, S and V denote respectively compactness, surface area and volume. For

comparison with the 2-dimensional compactness explained above, the variable for a

sphere can be calculated as follows. Surface area of a sphere is:




S = 4πr2

Here r is radius. Volume of a sphere is:

V = 4πr3 /3

Hence, in the case of a sphere, the ratio of surface area to volume is:

C = S/V = 3/r

This means that the larger the radius of a sphere is, the smaller the ratio becomes. In

reality spherical building is really rare however the authors favored the application of

same principle.

The last morphological property is derived simply by dividing total volume of buildings

by the number of buildings for each block, mean building volume can be derived and

expressed as below:

Regarding the limitations of the morphological indicators or properties used in ULM the

authors themselves found two items; one, the availability of data as the study area is

commercially very important city of Japan so they faced much obstacles to get the

required data and Second, there wide applications of ULM for comparison and analysis

internationally as well as domestically.




In “Netzstadt” method Oswald et.al (2003) used four morphological indicators on the

Wigger city of Switzerland and suggested how the analysis of those indicators can be

applied for the future sustainable urban planning and designing. These four indicators are

- Building Density

- Shredding

- Granulation

- Accessibility

The Netzstadt model proposes five criteria of urban quality namely identification,

diversity, flexibility, self-sufficiency and resource efficiency and relates these to specific

types of activity in the urban system. The Netzstadt method has put emphasizes on the

analysis of the morphological tools that describe the spatial characteristics of a territory

and as well as physiological tools--these refer more specifically to processes.

2.4.2 Working with Physiological Indicators

During finding the challenges for the compact city as a sustainable urban form, with the

support from past literatures Holden et al (2005) identified that three activities namely

housing, transport and food are the main source of the highest physical consumption in

the form of material flow, energy flow and waste generation and account for as much as

80 per cent of the direct and indirect environmental impacts by the households. The

authors have studied the relationships between land use characteristics and following four

distinct consumption categories:

- energy use for heating and operating the house;

- energy use for everyday travel;

- energy use for long leisure-time travel by plane; and,

- energy use for long leisure-time travel by car.

These four consumption categories have been regarded as ‘household consumption’

throughout the article. The authors conducted study on eight residential areas and tried to




find out a causal relation between the physical and non-physical characteristics of the

household using multiple regression analysis. The assumption of this causal relationship

as represented by the authors is as follows:

Assumptions on causal relationships between characteristics of households and their houses,

behaviour, consumption and environmental demands.9

In SOLUTIONs (Sustainability of Land Use and Transport In Outer Neighborhoods)

project Mitchell addressed the relationship between non-transport energy use with the

urban development and form considering from the previous studies that in the UK,

buildings account for over half of all energy consumed (compared to 41% in the EU, and

36% in the USA), with less than 25% each for transport and industry. The author

presented a table to show the sensitivity of urban form in terms of energy use. The table is

as follows:

Urban form: Land use

characteristics related

to dwellings/

residential areas

- Density

- Local mix

- Location

- Access to

private/public service

- Type of housing

Socio-economic and

Socio-demographic

background conditions

Attitudes/Preferences

Household

Consumption

Environmental

Demands

- Energy use for

travel

- Everyday travel

- Long leisure-time

travel by car

- Long leisure-time

travel by plane




Mitchell assessed the building stock energy use by using two options; one is activity-

energy coefficient method where building stock energy use is calculated as a function of

activity type, floor space, and specific energy use coefficients (Gj m2

yr) for each activity

and this option is suitable to the whole city scale; second option is LT method (Lighting

and Heating method) which is mostly suitable for neighborhood scale and related with the

geometric form of territory such as building volume, height and plan depth, the suggested

unit is KWh m2

yr. Mitchell showed the effect of density on energy use for naturally

ventilated offices in London by the following figure.




Oswald et.al (2003) again in the ‘Netzstadt’ proposed a set of indicators for the analysis of

physical process of the cities. They compared the urban system with living organism and

selected the transport and transformation of materials and energy as the physiological

processes i.e. urban metabolism. According to the authors, physiological tools are

required to understand an urban system’s physical resources and management so that the

findings can be implemented for planning a new urban system. In the ‘Netzstadt’ method

four basic activities are identified which provoke the flows of material, water, energy and

waste in an urban system; these activities are




- to nourish

- to clean

- to reside and work

- to transport and communicate

Assuming that the urban metabolism system is highly driven by the anthropogenic

activities, the proposed physiological indicators are as follows:

i. Density of inhabitants (inhabitants/sq. km of settlement area)

ii. Density of workplaces (workplaces/workforce inhabitants)

iii. Density of services (workforce of tertiary sector/total workforce)

iv. Density of institutions (number of specific institutions/ 2000 inhabitants)

v. Workforce (flows) (Commuter ratio)

vi. Students (flows) (Commuter ratio)

The two other desirable indicators are as suggested by the authors are

- Consumers (flows)

- Information (flows in bits and bytes)

2.5 Multi Scale Assessments of Environmental Performance and GIS

Planners and policy makers operate at various scales to deal with different types of

environmental problems of interest within their jurisdictions and seek solutions to handle

the complexities of natural and human actions cause these problems. Indicators for

assessing environmental performance vary from various levels we want to assess e.g.

indicators for assessing a country will be different for the indicators assessing a region or

city, similarly the indicators to assess the latter will not be effective to assess in case of

community level. Also within each level there are multiple variables that needed to assess

for measuring sustainability. Therefore, planners and decision makers sometimes

concentrate on the evaluation of multi-scale assessment of environmental indicators to

measure the performance of environment. This integrated approach enables to create a

planning space where it is possible to take planning decision in more scrutinized way that

embrace possible all aspects of environment.




Isabelle (1999) developed a model based on the statistical tool i.e. regression analysis

which establishes a relationship between the electricity consumption per capita per year

with some demographic and socio-economic characteristics or variables of few Canadian

cities i.e. average inhabitant age, the annual degree-days below 180C, the urban density

(inhabitants per km2

), the share of homes heated by electricity, the standardized landwealth per inhabitant and planning, leisure and cultural expenditure per inhabitant which

the authors represented respectively by AVGAGE, DEGDAY, DENSITY, ELECTRIC,

LANDWEAL, PLANLEAS and established the model as:

Y = -16964+389.47*AVGAGE+1.016*DEGDAY -

0.498*DENSITY+86.47*ELECTRIC+0.1159*LANDWEAL

By Y she indicated the dependent variable, the annual city electricity consumption perinhabitant. The author excluded industrial electricity because the electricity consumption

per capita for industrial use is not congruent with cities electricity consumption.

The model seems very interesting and simply represented an important relationship

between the urban population density and electricity consumption but in this model no

morphological characteristics have been included.

Yang (2007) used such a multi-scale analysis for measuring urban environmental

performance of Singapore city. He conducted macro level analysis for tracking material

stock in Singapore and micro level analysis for multi-objective decision making within

three aspects of environmental performance namely Surface cover ratio (for greenery and

urban runoff rate), Sky view factor (for solar availability) Material efficiency (for

ecological efficiency of material stocks and usage) and applied to seven categories of

housing, i.e. multi-storied housing, row housing, single family housing, special buildings,

condominium, mixed use and educational. He stated the outcome of the study as multi-

objective decision making space and represented by a two dimensional graph, an example

is as follows




.

Geographical information science develops techniques for spatial analysis and decision-

support in environmental analysis. Geographical Information Systems (GIS) are

extensively used for data processing and visualization of available data sources as well as

the handling, modifying and retrieving of data to apply environmental assessment models.

Most of the studies referred in this chapter are done with the help of GIS especially thestudies focused on morphology; land cover, land uses and so various spatial analyses have

either done in GIS platform in whole or converted the remotely sensed data into GIS

format. The systems of analysis as conducted by Adolphe’s (2001) Morphologic, ULM by

Yoshida et al (2005), Netzstadt (2003), and Perry Yang (2007) are based on GIS. Wu et al

(2006) performed a GIS-based moving window analysis for quantifying the effect of

urbanization on the landscape ecology. Pauleit et al (2000) used remote sensing and GIS

analysis for assessing the environmental performance of land cover types very

successfully.

There fore, the capabilities of GIS for doing multi-purpose data analysis and

modifications, visualization and prediction, queries have induced the researcher,

professionals to apply GIS tools for the specific purposes of land use management,

transport and pollution prediction, housing stock and environments mapping as well as in

evaluation of built environment.

Environmental Decision Space

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

80.00%

0.00% 10.00% 20.00% 30.00% 40.00% 50.00% 60.00% 70.00% 80.00% 90.00%

Materials Stock Efficiency Percentage

O p e n / G r e e n C o v e r a g e P e r c e n t a g e o n S i t e

Special Buildings

Row Housing

Educational

Mixed UseSingle Family Housing

Multi-Storied Housing

Condominiums




2.6 Knowledge Gap

It can be certainly said that there are a number of very influential researches on both the

morphological and physical characteristics of the city but very limited efforts have been

made on the relationship between these two at the same time and in GIS environment.

Though Holden et al’s (2005) research pointed on the relation between land use

characteristics and household energy consumption; however, merely accounted the

electricity consumption and considered only one spatial indicator. Similarly, hardly any

research found that dealt with the relationship between spatial characteristics of any urban

unit and the material flow. Therefore, in this research a multi-criteria analysis of

morphological indicators and physiological indicators are to be carried out within a GIS

platform.



Morphological and Physiological Analysis for Measuring Urban Environmental Performance: A Case

Study of Bukit Panjang

Methodological Framework 3-1

Chapter 3

Methodological Framework

3.1 Selection of Study Area

In the process of selecting study area some factors like data availability, recent

development as urban area, presence of diverse environmental attributes are considered.

One of the new towns of Singapore named ‘Bukit Panjang’ was selected, therefore, as

study area with the consultation of distinguished research supervisor and past researchers

under his supervision.

3.2 Collection of Necessary Maps

There was no individual map so far prepared for Bukit Panjang that meets the research

interests. Therefore, a wide range of digital data were needed to collect from Singapore

Land Authority and Urban Redevelopment Authority; paper based maps from Information

Resource Centre of School of Design and Environment, NUS and from various other

discrete sources from which the concerned areas and features were delineated using

various software.

3.3 Literature Survey

The literatures that deal with simultaneously urban morphological and physiological

characteristics are not satisfactorily available. Very limited literary resources could be

gathered to enhance the knowledge of these two diverse fields of urban environment andthen tried to explain their implications on my research subjects. Especially while

considering the human induced indicators e.g. fossil fuel or electricity consumption, the

concepts of urban physiological analysis are relatively new field of knowledge. Therefore,

searching literatures to find effective physiological analysis parameter for sustainable

urban planning appeared as a daunting task. Various journals namely ‘Journal of Urban






Design’, ‘Computers, Environment and Urban Systems’, ‘Environment and Planning B’,

‘Landscape and Urban Planning’, as well as few chapters of some text books especially

‘Netzstadt’ were very useful for realizing my research subjects.

3.4 Identification and principles of Indicators

For morphological analysis of the study area, a number of indicators were primarily

selected from various literatures (discussed in literature review chapter). Ironically, most

of them involved 3 dimensional calculations of urban elements and required time

consuming manual calculations from diverse fields of data. Therefore, considering our

time and resource constraints some indicators were chosen mainly based on the indicators

used by Oswald and Baccini in ‘Netzstadt’ by modifying few variables used for

mathematical calculations. It should be claimed that, the indicators used in this study are

not similar to the indicators used in ‘Netzstadt’. These three indicators are:

i. Plot ratio

ii. Degree of subdivision

iii. Granular index

iv. Level of accessibility

Similarly, few indicators were available for urban physiological analysis but most of them

are concentrated on highly voluminous data collection and complex calculations so very

simple indicators have been chosen for their relatively availability and calculability. The

two indicators considered in this research are:

i. Material Intensity

ii. Electricity Use Intensity

The major activities and materials in the urbanization process are the construction

industries and the building materials respectively. It is difficult to compile a consistent

series of these building materials information over time since data on all the end uses are






not available. We therefore select a small number of reservoirs to use in making the

assessment of the current stock. The criteria for selection are,

1. Major materials used in the construction

2. Significant amount of material available for reuse like steel and aggregate.

3.5 Collection and Compilation of Data and Information

The main source of data was the Singapore Land Authority from where copyright

protected land information of whole Singapore was collected in GIS format with the help

of the research supervisor. However, unfortunately all the required information on details

of a parcel of land were not included in the SLA data therefore data and information also

were collected from URA and synchronized with SLA data in ArcGIS 9.2 platform. The

construction materials data have been collected from BCA and HDB and the electricity

consumption data has been collected from Singapore Power, questionnaire survey and

concerned official interview.

After the collection of the data they are compiled in ArcMap 9.2 and Arc Catalog 9.2 as

well as in MS Excel and STATA according to desired order of necessary calculations.

3.6 Calculation of the Indicators

The following mathematical equations are used to visualize the data and the equations

have been derived by slight modifying of the original equations as are in ‘Netzstadt’. All

necessary variables have been calculated in ArcMap using command like ‘Calculate

Geography’, ‘Select by Attributes’, Select by Location’, etc as the base database only

contain the spatial and oracle attributes.






a. Building Density:

The mathematical formula used for visualizing the building density of Bukit Panjang is as

below

Plot Ratio =

b. Degree of Subdivision

Degree of subdivision is realized using the relationship between Degree of coherence, C

and Degree of Subdivision, S is

S = 1/C

The Degree of Coherence indicator targets the very serious problem of fragmentation or

shredding the totality of the territory into numerous parts, which ultimately hinder future

development of the land. A highly splintered (i.e. because of road cutting through or small

scale allotment structure) land offers less opportunity for urban intervention, than a

coherent one. Degree of Coherence is an index for the statistic probability of individual

building (Ai) to be superimposed if the building footprints divide land parcel in various

segments. For calculating the degree of coherence for land parcel the formula used in this

study as follows:

C= ∑ (Ai /A tot)2, which equals C = 1/ A tot

2∑ Ai

2

Where Ai = Building footprint (BF) area (m2) of building i; and A tot = total BFA of all

buildings within the same parcel with building i.

∑ (Building Footprint*No of stories)

Area of the particular parcel of land






c. Grain Sizes

In this study to visualize the granular index or grain size differences the gross floor area

has been considered to see the mixing rate of the various types and heights of buildings.

d. Degree of Accessibility

Accessibility has been measured here based on the land parcels’ proximity to nearest level

of road network where a hierarchy of road network is made based on their functions

namely Expressway, Arterial road, Distributor road and Access road which are again

weighted respectively as 1, 2, 3 and 4. Finally a 50 meter buffer is used to estimate level

of accessibility of the land parcels and the built elements within them. 50 meter buffer is

used because previous researches showed that a person’s approximate ability to walk 50

meter without much trouble.

e. Material intensity

In this study actually material intensity has been elucidated with the concept of the stock

of four major construction materials namely still, cement, coarse aggregate and fine

aggregate for various structures statistics of which have been collected from Building and

Construction Authority (BCA) accounted over a period from 1993-2006. The stock has

been calculated in average kg per square meter. This stock then estimated for each land

parcel as demarcated by Singapore Land Authority (SLA) to visualize the density of the

four major construction materials on the land lot basis.

This stock (kg/m2) is then converted in to the density by multiplying the Gross Floor Area

(m2) of various built structures with corresponding average material stock value.

Therefore,

Material intensity = Material Stock (kg/m2) * GFA (m

2), which is calculated on the parcel

basis.








The whole methodological framework can be shown by the following chart:

Online ResourcesOnline Resources

Proposals and Recommendations

Collection of Data and Information

Calculation of the Indicators

Analysis and Visualization of the Indicators

Secondary SourcePrimary Source

Identification and Principles of the Indicators

Selection of Study Area

Collection of Necessary Maps

Literature Survey

Online ResourcesJournal Text Books

Figure 3.1: Methodological Framework





Study Area 4-1

Chapter 4

Study Area2

4.1 History and Location

Urban Redevelopment Authority (URA), a statutory board of Singapore under Ministry of

National Development (MND) divided whole Singapore in 55 planning areas in its aim to

create a tropical city of excellence. The study area for this research, Bukit Panjang, is one

of the planning areas of Singapore. It is situated in the Central North-Western part of

mainland Singapore. Bukit in the Malay Language means "hill" and Panjang mean "long".

Bukit Panjang literally means "long hill" which gets its name from the long range of low

hills which ends in Bukit Timah to the south (Wikipedia).

This area used to comprise rural settlements in early 1990's. Today, it has many suburban

facilities like the Cold Storage Dairy Farm, as well as factories and granite quarries. Bukit

Timah Hill, which means 'tin hill' in Malay, is Singapore's first and largest Nature

Reserve. Today, Bukit Timah Nature Reserve is set aside of the Bukit Timah expressway

for the propagation, protection and preservation of the indigenous fauna and flora of

Singapore.

Bukit Panjang can be found in the Central North-Western region of Singapore. There are

seven sub-zones in Bukit Panjang; Senja, Sujana, Fajar, Bangkit, Bukit Panjang, Dairy

Farm and the Nature Reserve. The size of Bukit Panjang Planning area is about 9 Sq Km

with an estimated 55,000 residents.

4.2 Profile of the Study Area

There are many new HDB Towns here, namely Senja, Bukit Panjang, Fajar and Bangkit

as well as private estates comprising of both condominiums and landed property like

terrace housing can be found here. Bukit Panjang has been planned by URA to develop as

2http://www.streetdirectory.com/travel_guide/singapore/singapore_district/244/bukit_panjang.php





Study Area 4-2

residential and nature reserve area. As Bukit Panjang is situated opposite to Choa Chu

Kang, the town is accessible via the Bukit Panjang LRT from the Choa Chu Kang MRT

station. The Light Rapid Transit or LRT is a smaller Rapid Transit line transport

passengers deeper into the residential areas.

The study area is surrounded by Kranji expressway at the northern side, Bukit Timah

expressway on the eastern side, dairy farm road on the southern side and interconnected

Woodland roads and Upper Bukit Timah road on the western side have made the study

area almost like a trapezium. Buikt Panjang road goes through the study area connecting

Woodland and Upper Bukit Timah Road with Bukit Timah expressway.

A map of Singapore and the study area generated from Google map are shown in the next

page.





Study Area 4-3

Map 4.1: Singapore Map3

3 http://www.mightyminds.com.sg/images/Maps/sing%20map%20large%20lam.jpg

Map 4.2: Study Area (Bukit Panjang)



Proposed Indicators for Env. Analysis of Bkt Panjang 5-1

Chapter 5

Proposed Indicators for Environmental Analysis of Bukit Panjang

5.1 Urban Environmental Performance

Urban areas should be the domain of accelerating sustainable human settlement

development keeping pace with the ever increasing rate of urbanization. For this sake, it is

an essential step to analysis the particular urban environment, which is the most

significant aspect for ensuring sustainable development. Urban environment among others

is primarily comprised of the spatial patterns developed by human activities as well as the

management, process and flow of resources used in various spatial units by human.Referring various studies Alberti (1999) mentioned that urban spatial configuration

implies the individual choices that have consequences for the environment. In fact energy

flow is considered the major environmental implications when considered the

morphological character of the cities which is supported by various studies (Perry, 2007;

Adolphe, 2001; McPherson, 1994) that found the relationship between the spatial

structures and solar radiation distribution and also the spatial structures are supposed to be

an important set of indicators for future energy supply and distribution (Owens, 1986).

In this research, analyzing urban environmental is mainly concerned with the concept

“urban metabolism’ and material flow in terms of construction materials and energy flow

in terms of electricity uses. So it is required to account material intensity by material

types, by structure types as well as change of their intensity over time. Therefore these

two play vital role in analyzing environmental performance for urban areas. To measure

urban environmental performance therefore need to find relation between the urban

morphological characteristics which are subjected to be modified by human interventions

and the energy-material flow to accomplish various anthropogenic activities. In this

research two different set of indicators namely morphological and physiological are

selected for analyzing urban environment of Bukit Panjang.




5.2 Morphological Indicators

The understanding of urban environment using morphological indicators are mainly based

on long time experimental knowledge where some apprehended and easily understandable

rules are used to define the environment. These rules i.e. geographical, geometrical,

economical, topological, social etc. interact with each other again in various complex

ways for various new urban areas and therefore sometimes very difficult to ascertain their

phenomena. In effect an urban environment is the out come of the both effects of

generation of urban shape and change of the shape which in turn determine the quality of

environment. In Netzstadt (Oswald and Baccini, 2003) three factors are mentioned behind

the generation and change of the urban shapes namely resistance, aggregation and

coherence. The resistance may be external and internal factors which affect both systems

of urban shape either by hindering or keeping the prevailing stand. The surrounding

neighborhoods are believed to have significant effect on the urban environment by

segregating or integrating features in urban system.

In this research four set of morphological indicators have been used to understand the

environmental conditions of the urban system:

i. Plot ratio


iii.Granular index

iv. Level of accessibility

The explicit objectives for working with these indicators are to find out the weakness and

strength of a particular shape of urban environment therefore directing way to enhance

new design shape to improve the urban environmental quality. Another substantial aim of

using morphological indicators is to get enough bases to assess the strength and weakness

of the selected urban environment with excellent interpreting abilities and directing to

desired conditions.




i. Plot Ratio:

It can be undoubtedly said that urban landscape are frequently disturbed by the

morphological elements i.e. loss of natural vegetation, land destruction and erosion,

unsuitable and exotic species introduction due to gardening and landscaping, and the

restriction of wildlife movements by infrastructures and subdivision of land parcels. One

of the morphological effects is related to buildings in the urban environment as a spatial

function in the form of density and pattern on one side and the temporal component in

another side in the form of changing of density and pattern over time. Understanding the

effects of buildings density and pattern on urban environment and landscape and its

temporal changes may give implicit view of current environmental performance and

provide sufficient responses for future urban design. Building density can have positively

correlation with the environmental attributes of a specific site because the density exhibits

the concentration of activities, consequent flows of materials and energy.

Plot ratio is the simple measure of building density i.e. the ratio between gross floor areas

(GFA) in respect of surface occupied by sealed structures to the land parcel. Plot ratio is

usually computed as the ratio of the gross total of the areas of all floors of the buildings on

a site to the area of land within the land lot areas. Plot ratio is a very important planning

tool for land development particularly in zoning regulations as well as an analytical tool

for existing situation of any urban scale; sometime it is not only an urban planning tool

and land management issue, but also an indicator of a city’s historical evolution, because

the buildings constructed in different periods have different plot ratio as they are of

various styles and vary greatly in land occupancy. In Singapore plot ratio is used as

predefined number that is used to control the height/form of a particular development.

Each plot of land is assigned a particular plot ratio albeit not always the same. Architects

are not to exceed this plot ratio in their design or development charge may be imposed. In

all cases the plot ratios to be maximized will depend on the spatial context that includes

built form, character and sizes of land parcel and existing or potential public transport

capacity to avoid over development of sites and to prevent congestion. Plot ratio has also




played an important role in the process of preservation and conservation of built form

within the City Centre.

Plot-ratio as well as other urban design criteria has been a generally effective method of

controlling building height and density for new urban development. It is an important

indicator to promote resource efficiency of a parcel of land. It relates the built up area

with the total size of the parcel.

The mathematical formula used for visualizing the building density of Bukit Panjang is as

below

Plot Ratio =


The subdivision of land is an integral part of the development and uses of land are very

often regarded as the first step in the development process along with several

environmental implications. Subdivision and land use are closely related, because

subdivision generally creates new allocation of land for other uses that obviously differ

from the main use from where the new uses are sub-divided. Subdivision also establishes

the pattern and shape of development for a locality as well as impact on a range of

environmental values e.g. ecological amenities, cultural and biophysical values. A single

land parcel can be subdivided for multiple purposes in various ways that may be visible

and invisible sometimes like road infrastructures, building establishments as visible

elements and administrative boundaries of various scales may be as invisible. It is

hypothesized that the higher subdividing thresholds to overcome during passing a land

parcel the less interaction between the subdividing elements therefore high resource

consumption should be observed. Subdivision of land provides for the changing of

∑ (Building Footprint*No of stories)

Area of the particular parcel of land




property boundaries and creation of new allotments. These changes of explicit and

implicit boundaries of a land parcel together with subsequent developments can give rise

to adverse environmental and social effects and resource management issues within the

urban system.

Sometimes land subdivision may not have a direct impact itself but establishes a pattern

and disposition of land that may result in significant costs to the community and degree of

subdivision is required to estimate to know how shredding effect created by subdivision

may appear as unsustainable in the long run, such as:

i) The demands for infrastructures services and resources may appear beyond planning

projections by the urban community in the long term. The need for public facilities arises

from development, but is most appropriately integrated with the subdivision of land.

ii) The ecological habitation can be fragmented by the shredding effect of subdividing the

land in various competing uses.

iii) The visual quality of the urban environment may change through unsuitable intensity

or direction of development.

iv) Absorption ability of the ground for rain water and other effluents may be reduced due

to increase of impervious surfaces in any subdivision by increasing road, parking spaces

and building roof.

vi) New subdivisions certainly need access to nearest higher order transportation network.

As well as divisions of land parcels for providing new road infrastructures may

disintegrate the functional coherence of a land parcel as well as hinder free movement,

communications and mutual interchange of all kind of goods, services and living beings.

vii) Shredding of land by subdividing existing developments in the form of different titles

and consequent developments may need to conciliation the amenity values and the




environmental quality including access, utilization of outdoor space and maintenance, and

can also trade off redevelopment potential.

viii) The surrounding splendid natural landscapes can be adversely affected by the means

of habitat fragmentation and introduction of pests that may lead to the removal of

indigenous species.

ix) Lack of coordination between subdivision and infrastructure will require the explicit

trade off between environmental impacts and necessary provision of infrastructures as

individual and isolated subdivisions are closely integrated with the development process

which generally requires the provision of infrastructure to occur and in this case

sustainability is an issue.

x) The subdivision and development of land also bring confliction between the city’s

natural and cultural features. The subdivision processes may lead to the creation of a

fragmented parcel that is inappropriate for planned development, boundaries or building

platforms therefore sometimes overlook the effective protection of natural ecosystems and

vulnerable environment.

The environmental effects of subdivision are highly dependent upon the extent, scale, and

type of land use changes. Generally other things being equal, that the smaller the average

area of subdivision, the larger the impact of subdivision. To understand the effect of land

subdivision on urban environment a term ‘degree of subdivision’ is used as a

morphological tool which is a reciprocal term of degree of coherence. Degree of

coherence then can be defined in a simple way in this regard that how freely the elements

of one subdivision including living organisms can interact with those of other

subdivisions. The higher degree of subdivision in a site means the elements of thesubdivisions are less coherent as the bondings among the congruent features of

environment become much shredded. Discontinuity or splitting up lands can inevitably

weaken the smooth functioning of ecological and environmental services. Therefore

measuring the degree of subdivision of the land parcels is a very important step to analyze

a particular urban environment.




In calculating the degree of subdivision, another related term ‘degree of coherence’ also

needs to be calculated and in this regard, the formula of ‘degree of coherence’ has been

modified based on the tenet as explained in the ‘Netzstadt’ i.e. the probability of

encounters and prevented contacts within a single land lot’

The Relationship between Degree of coherence, C and Degree of Subdivision, S is

S = 1/C

Degree of Coherence is an index for the statistic probability of individual building (Ai) to

be superimposed if the building footprints (BF) divide land parcel in various segments. C

has been calculated for this study based on ‘Netzstadt’ with minor modification to fit it for

the current study scale as follows:

C= ∑ (Ai /A tot)2, which equals C = 1/ A tot

2∑ Ai

2

Where Ai = BFA (m2) of building i; and A tot = total BFA (m

2) of all buildings within the

same parcel with building i.

BFA= Building Footprint Area of built structures present in a land parcel;

due to ample building structures in the study site, the GFA has been

considered here for the formula.

iii. Granular Index-1

The indicator has been developed and manipulated for urban analysis from the discipline

named ‘Petrography’ or the study of rocks where the relationship between the content of

mineral and textures in a stone is described in detail. Used as metaphor this indicator

represents the relation of the elements i.e. buildings of a land parcel to itself in terms of

quantity and size. In fact granular index is a matrix of grains that are emerged from

various anthropogenic and natural or ecological features in a land parcel or by their

subdivisions. As granular index is the aggregations of the grains come up with the

breaking up a continuous and bigger object, this can be hypothesized that this index is

helpful to understand the corresponding urban environment in terms of its arrangement in




a larger scale environment. This grains are diverse in size and shape and this mingle can

be called as ‘mixing ratio’. Grain size of the urban elements is useful for measuring

permeability i.e. the movement of people, air, light and other basic amenities. Very

common example can be mentioned here as two building with contrasting height on a

same land parcel; the taller one must hinder the lower one on the way of air and light

flow. This situation may appear more complex. The permeability of the environmental

and anthropogenic flow to a large extent depends on the buildings occupied space as well

as their rate of mixing with each other therefore. The higher mixing ratio and grain area

mean less permeability and vice versa (Netzstadt, 2003).

It is very difficult to show the obvious relation between the heterogeneous shape and area

of various elements in a land parcel and the degree of permeability by any mathematical

formula rather it is a qualitative indicator that can be perceived on visual ability from a

satellite or GIS translated map. In this study a granular index mapping has been created

based on the gross floor area.

vi) Level of Accessibility:

Accessibility simply refers to access to nearby public transit, easy mobility along streets

and through buildings, and explicit routes of way out in emergency situations. These are

much expected features of an urban environment for smooth functioning for most of the

physical elements of environment. Level of accessibility defines the relative easiness at

which local amenities and facilities can be reached. Accessibility determines one selected

land parcel’s relation with the overall network system from or to the location. This

indicator is useful to determine the importance of a selected lot in terms of its access to

diverse modalities and transit lines.

One land parcel’s accessibility level determines the relative importance of the parcel in

terms of equity, economic value and no of links connecting across scale. In this study the

level of accessibility of each parcel is determined using its proximity to the nearest road

hierarchy. The road has been given weight according to their hierarchy namely,




1 – Expressway

2 – Arterial Road

3 – Distributor Road

4 – Access Road

A buffer of 50 meter has been used to find land lot within the mentioned distance of

selected hierarchy of land. It can be hypothesized that a piece of land’s accessibility level

is determined from its proximity to higher level network. As the highest level road

network is ‘expressway’ and this is not allowed to have direct access from any settlement

lot; therefore within its proximity any parcel of land is not desirable. Consequently, the

expected closest proximity of road network is arterial road which is supposed to be the

interface for a leap in scale of destination.

5.3 Physiological Indicators

Physiological indicators are used in this research to analyze the environmental

performance of an urban system as to augment the morphological indicators from the

material and energy flow viewpoint. The physiological parameters provide suitable

measures of the magnitude of resource exploitation and waste generation to be used as

indicators for sustainable urban planning and designing. This can be compared that an

urban system is like a human being that needs materials and energy for metabolism and

hence anthropogenic resource management is concerned. And the built environment is an

unavoidable outcome of this physiological process or to say ‘urban metabolism’. Recently

significant numbers of studies, researches, articles and journals have been published on

this highly postulated topic especially this aspect of urban environmental sustainability

has brought multiple stakeholders to be engaged to play corresponding role cautiously. It

is believed the morphological characteristics of cities are one of the factors for pushing up

of urban metabolism (The encyclopedia of earth). Metabolism can be quantified by

tracking the flow of matter and energy within the city illustrating trends in human energy

and material fluxes.






It is difficult to compile a consistent series of these building materials over time since data

on all the end uses are not available. We therefore selected a small number of reservoirs to

use in making the assessment of the current stock. The criteria for selection are,

1. Major materials used in the construction

2. Significant amount of material available for reuse like steel and aggregate.

In this study a statistics of the stock of major construction materials namely still, cement,

coarse aggregate and fine aggregate for various structures have been collected from

Building and Construction Authority (BCA) accounted over a period from 1993-2006.

The stock has been calculated in average kg per square meter. This stock then estimated

for each land parcel as demarcated by Singapore Land Authority (SLA) to visualize the

density of the four major construction materials on the land lot basis.

The estimated average material stocks for various built structures as collected from

Singapore Building and Construction Authority are as follows:

Table 5.1: Material Stock in Bukit Panjang from 1993-2005

A) Residential Buildings B) Commercial/Worship Buildings

Items Average kg/ m2


Steel 23 Steel 40

Cement 74 Cement 118

Coarse Aggregate 201 Coarse Aggregate 302

Fine Aggregate 158 Fine Aggregate 230

C) Mixed use/

Institutional Buildings F)Services (industrial)



Steel 40 Steel 57

Cement 109 Cement 137

Coarse Aggregate 285 Coarse Aggregate 352

Fine Aggregate 219 Fine Aggregate 269Source: BCA, Singapore




This stock (kg/m2) is then converted in to the density by multiplying the Gross Floor Area

(m2) of various built structures with corresponding average material stock value.

Therefore,

Material intensity = Material Stock (kg/m2) * GFA (m

2), which is calculated on the parcel

basis.

ii) Electricity Use Intensity

Electricity is the major energy flow in urban system dominantly driven by anthropogenic

activities and intensity of its use is increasing with the rate of increasing urbanization. But

it is evident that urban energy consumption is higher in developed countries than the

developing countries. High energy consumption has vital implications in urban

environment as it is itself produced from depleting natural resources like natural gas,

water, air as well as produce additional polluting gas like CO2, waste energy like heat

during the production process of electricity as well as its use in cooling and heating the

built structures. Previous study (Perry, 2007) found that Singapore is a compact city and

studies also show that compact cities consume high electricity.

There are various indicators to track electricity consumption in urban uses like per capita

electricity consumption, household electricity consumption, GDP per electricity

consumption etc so. Each indicator has its own limitations to represent exact scenario. For

this research, a different indicator namely ‘Electricity Use Intensity’ is tried to find out

where electricity consumption by per unit area of a household has been accounted. There

is both the building gross floor area for various built structures of Bukit Panjang as well

secondary data on electricity consumption by various housing typologies has been

collected from Singapore. As most of the built structures in Singapore including Bukit

Panjang are combined or row, so individual household area has been calculated based on

GIS data, Google image, field survey and online Singapore properties information. Again

synchronization has to be made between the housing typologies defined separately by

SLA and SP.






K Block (can be residential or commercial)

S Standard

U Walkup

A Apartment

E Executive Condominium

R ResidentialUM Walkup (Main address)

US Walkup (Sub address)Source: Singapore Land Authority (SLA)

With the help of SLA official the ambiguity of the descriptions again removed by the

following clarifications:

HDB = Public Housing/flats developed by Housing Development Board

Residential = Private residential (eg. landed properties)

Standard = Standard buildings built by BCA (usually Public/ Commercial

buildings)

Executive Condo = Condo housing developed by HDB

Condominiums = Private Development

Walkup = Usually old HDB without elevators (eg. 4 storey flats)

Apartment = service apartments

UM = Part of U (with main address)

US = Part of U (with sub-address)

To include the electricity intensity data in GIS database the author needed to bring the

terms for building typologies used in table 5.2 and 5.3 with the SLA defined building

typologies, so few adjustments and assumptions are needed especially five types of HDB

buildings had to bring under one typology namely ‘H’ or ‘HDB’ as for getting final output

and regression analysis. From the field survey it was assured that the HDB (3+ rooms) is

predominant therefore the average electricity consumption is made based on that of HDB

3-rooms, 4-rooms and 5-rooms by calculating weighted average. Same statistical method

has been followed for other buildings which have no unique features i.e. building size.

Formulation of this indicator is mainly focused on residential buildings as the commercial

and industrial building are not unique in character so determination of electricity




consumption per unit area of buildings may raise the question of validity. As this is a very

time constraint research, an approximation was highly required to exhibit kind of

relationship with other indicators.

Thus, based on above estimation and cross-estimation the following table has been

generated:

Table 5.5: Calculated Electricity Use Intensity for Built Structures in Bukit Panjang

Code Electricity Use Intensity (kWh/ m2)

C 8.76

I Unknown

H 3.53

K ~ H

S Unknown

U ~ H

A ~ C

E 3.49

R 9.22

UM ~ H

US ~ H





Analysis and Findings 6-1

Chapter 6

Analysis of the Indicators and Findings

This is the vital chapter of the research where the various spatial and non-spatial data is

analyzed for finding out the environmental performance of Bukit Panjang Area. Before

starting the analysis of main indicators, some initial analysis of the study site

characteristics are shown below.

The total land area of the study area and corresponding built structures are as estimated

from the GIS based SLA data as follows

Figure 6.1: Share of Built and Non-built area

14%

39%

47% Building footprint

Road

Non-built areas

Table 6.1: Existing Characteristics of the Building typologies in Bukit Panjang

Building Types

No. of

Building

Average Building

Footprint (Sq.m)

Maximum

Floor

Average

Floor

Condominium 30 946.4315 30 18

Commercial centre 1 5754.3845 4 4

Executive 7 689.9606 30 27

HDB 323 1134.5193 30 17

Industrial 2 1922.0253 4 4

Block

(residential/commercial) 9 1223.9259 30 24

Landed Property 779 154.0503 30 3

Standard 222 569.6031 30 4

Walk Up 14 138.3957 3 3






Calculated from the GIS data of SLA, the above table clearly shows that Bukit Panajng is

mainly a residential area as designated in the Singapore Master Plan 2003 with highly

dense development (Map 6.1). It is also evident that the Master Plan of Singapore city has

put emphasize on the vertical expansion rather than horizontal expansion. At the same

time sufficient provision for accessibility and open space has been provided to cater the

population living on these skyscrapers. These observations are supported by the building

density mappings based on the plot ratio which have been collected from URA which is

described the next section..

The following table is showing the status of built structures in Bukit Panjang planning

area.

Table 6.2: Status of the Built Environment Data in Bukit Panjang

Building Status Count

Estimated 15

Existing 1284

Proposed 57

Under Construction 31

Out of 57 proposed buildings major are landed properties (R) which are in total 35,followed by Standard buildings built by BCA which are 15 and Condominiums are 7; in

case of under 31 construction buildings 29 are landed properties or terrace houses and

other twos are school buildings under Standard Building category (Map 6.2).

Government’s future plan seems concentrated on the disperse settlement as manifested

from the dominance of landed property like terrace and low height settlement in the

proposed building outlines of the SLA data.

The main reason for highlighting the proposed and under construction buildings is to find

out their impact on the urban physiological process based on the physiological indicators.
















6.1 Morphological Analysis

i. Building Density

The contour mapping based on the plot ratio (Map 6.3) is representing the topographical

scenario of Bukit Panjang where the various colored lines are drawn along buildings of

same plot ratio. Building density mapping of Bukit Panjang based on the plot ratio (Map

6.4) does not show consistently high dense built up area rather the plot ratio values are not

more than 3.5 and not less than 0.35. The darker color shows the maximum plot ratio, as

the contour lines tending to be lighter indicates low maximum density and tending to be

white indicates plots with no building. No significant fluctuation or variation of building

density is observed in the actual condition than the master plan 2003 developed by Urban

Redevelopment Authority for this area. Thus, a good tendency can be observed inimplementing planning principles of the Singapore master plan 2003.

The plots having higher plot ratio (>2.48) are mainly HDB building followed by landed

property and standard buildings. Again the highest plot ratio contained lots are mostly

occupied by condominiums and executive apartments. In condominium a series of

luxurious facilities e.g. swimming pool, tennis court etc services are provided for the

economically well off residents which mutually benefit all the residents of the

corresponding condominiums. This can be regarded as a sustainable approach in response

to land crisis of Singapore. The contour lines with lower plot ratios (< 1) represent 54% of

the total study area. The extreme low plot ratios indicate the presence of low building

volume means the morphology of built areas is consuming less resource. Again the

density map notice that the most of the low dense or no developed plots are ring shaped;

surrounded by plots with medium to high plot ratio therefore the ring shaped plot can be

used as community gathering or activity generating place.

As the plot ratio of various values are in a continuous shape along the periphery of the

study area, it can be envisaged that significant amount of primary ecological features has

been sacrificed. However, the make up attempts have been taken later to compensate the

natural vegetation undergone for development.
















ii. Degree of Sub-division

Map 6.5 is showing the map of the degree of subdivisions due to various built features

e.g. building outlines, road network, and land allotments. Map 6.6 is showing the map of

degree of subdivision where the dark shade is showing the corresponding plots and

surrounding plots are more subdivided. That means the more intense the color, more

subdivided and as discussed in the previous chapter that subdivision is the inverse value

of the degree of coherence, therefore more the intense colored plots are less coherent; the

built structures of the plots are less related to each other.

The significant subdivision is done by the street networks at the community level but high

to medium degree of subdivision also have been observed due to property boundaries.

However, it’s remarkable that relatively high degree of subdivisions is few in the study

area. An intensity of subdivisions is apparent in the portion of the map where mainly

landed properties i.e. terrace housings are present. This phenomenon is caused because of

the individualities of the terrace houses. The nil degree of subdivisions is observed in the

south east portion of the study area where because that portion of land parcels have no

built parcels, however some shredding is observed for the parcel boundary.

The study area is confined by two expressways namely Kranji expressway from north side

and Bukit Timah express way from east side, major arterial roads as woodland road and

upper Bukit Timah road in western side and by Dairy Farm road in the southern side.

Though a high degree of subdivision is marked in the northern side at the edge of Kranji

expressway, due to the presence of regional highway further subdivision may not be

possible towards north. However, a degree of subdivision is stands out along the edge of

western edges which is also accessible by arterial road showing development trend across

the road. Relatively less subdivision is observed along the Bukit Timah expressway. It

means there is no intensity of development is towards Bukit Timah expressway as on the

other side there is reservoir, which is a nature reserve of Singapore.
















iii) Granular Index

Granular index based on the Gross Floor Area (GFA) (which considers both height and

footprint area) has been shown in the map 6.7, indicates very heterogeneous granulation

interspersed with capacious grain sizes. Already mentioned in previous sections that Bukit

Panjang is mainly a residential area, and most of the buildings have been designed to

accommodate ever increasing population of Singapore without consuming lateral land

surfaces as well as having a uncompromising policies to let develop any squatter and slum

settlements. Therefore, the tall buildings are ideally predominant across the study area.

But the people are living in these residential buildings must need some social services like

schooling, commercial activities, medical services etc which have been provided mixing

with some residential units which have been categorized as ‘standard buildings’; this

buildings are not so tall as some HDB residential building situated at the North-western

side of the study area. Thus a complex mixture of grain sizes has been observed in some

part of Bukit Panjang especially around the Bukit Panjang ring road.

A homogeneous structure of grain sizes can be seen where the terrace houses are located.

As these are the landed properties, no scope for Governments intervention in future for

high density development. In terms of environmental permeability, the terrace housingparts are in suitable position as no larger grains are around those so there is easy

movement of air, sun and sound through the spaces. Of course the largest sizes of grains

are very few as in the granular index map, only 3 grains are found to have largest value

two of which have a visible buffer from the surrounding grains so they might not appear

as blocking the environmental flow to surrounding grains.











iv) Accessibility Index

Accessibility has been measured here based on the land parcels’ proximity to nearest road

network where a hierarchy of road network is made based on their functions namely

expressway, arterial road , distributor road and access road. These roads are again

weighted respectively as 1, 2, 3 and 4 therefore higher order road network is having lower

weight. Finally a 50 meter buffer is used to estimate level of accessibility of the land

parcels and the built elements within them. The concept behind 50 meter buffer is taken

from transport engineers that a person can comfortable walk up to 50 meters.

Map 6.8 shows the topographical findings of the level of accessibility in the Bukit

Panjang. The lighter areas represent accessible to highest order (lowest weighted)

network, the darker areas have access to the lower to lowest order road of the hierarchy.

Similar results have been represented in the Map 6.9 where the accessibility level has

been shown on parcel basis. Some plots have no accessibility in the southern parts of the

map which are mainly vegetated areas. As the closest residential areas are mainly terrace

houses, the inaccessibility of the vegetated sites will retard the potential developers to

develop those ecologically important lands.

When land market is considered, those plots have higher values which have easy access to

the higher order transport network for traveling without delay and with minimum

distance. In that case the land parcels having close proximity to expressway but

expressways do not have interfaces with the local access; they are only accessible through

arterial road. Thus the land parcels are showing easy accessible to the expressway in a bad

position in a sense that they have to depend on either distributor road or local access road

for accessibility and in fact most of the settlements have been formed in the land parcels

which are in proximity of either distributor road or local access road. So, it can be said

that higher level accessibility has a prohibiting effect on the settlement development.
















6.2 Physiological Indicator

i. Material intensity

In this research the main reason for accounting Material intensity is to analyze the stock of

major construction materials for various buildings as a part of urban physiological

process. Here four construction materials namely still, cement, coarse aggregate and fine

aggregate are used to visualize the concentration of their uses on the plot basis. Another

main intention for this analysis is to find out the material efficiency for various building

blocks.

The maps 6.10 to 6.13 indicate the density of four construction materials in the Bukit

Panjang. Ideally all the four materials’ intensity show similar trend in terms of their share

in construction for various types of building. Thus it is clear that materials stocks may

vary from building typologies but the share of construction materials remain same. There

is a direct and positive relationship between the GFA and material stocks in buildings,

therefore material intensity is higher in those parcel of lands where more than 20 storied

condominiums and other buildings are situated. And low materials are concentrated in the

region where average three storied terrace housings are located. The material stocks arestill growing as there are lot of estimated and proposed buildings but as discussed early of

this chapter that majority of proposed buildings are terrace building which has the highest

material efficiency (kg/m2) according to a study done by Perry (2007) on the material

stocks for various building typologies, the likely material flow can be possible to keep

limited. These maps are simple representations of the four types of materials’ stock in the

Bukit Panajng without accounting their life cycle assessment, inclusion of which must

give truer picture of the effect of material flow in urban environment. But it can be

assumed that after demolition of a buildings, the still can be reused out of the four

materials, but cement should remain as a binding material with the two types of aggregate

which are most of the times are dumped as wastes and this wastes have again adverse

impact on the environment.


























ii. Electricity Use Intensity

The very simple indicator to account the energy flow into the urban environment based on

the relationship between building area and electricity consumption is named as Electricity

Use Intensity also indicate same trend as like the Material intensity (Map 6.14). Thus it

can be hypothesized that the physiological indicators used in this study are positively

correlated with each other. The main use of electricity in the high rise buildings are air

condition. Due to the stable weather condition in Singapore, electricity doesn’t need

notably for heating purposes in the buildings. An explicit positive mutual relationship

among the socio-economic conditions, population density and electricity consumption

could be found. In case of both factors per capita income and population density are high

for Singapore; so literally it can be assumed that electricity is highly consumed in

Singapore.

Electricity is the only static source for producing heat in urban environment for the

building cooling process. Therefore high electricity consumption by the residential

buildings in the Bukit Panjang inevitably affect the micro-climate and induces along with

other dense settlements the effect of urban heat island for whole the island wide state.

6.3 Correlation and Multiple Linear Regression Analysis

Apart from the individual analysis of the two sets of indicators another important part of

this research is to find the mutual effects of the two different set of indicators that affect

urban environment. Keeping this in mind, Pearson correlation coefficients have been

measured using commercial statistical software STATA. Granular index represents at the

calculation level based on land parcels exhibits same result as plot ratio therefore

excluded while measuring correlation to avoid data redundancy.

The coefficients of Pearson correlation for the two sets of indicators are given at table 6.3

where PR, SUB, ACS, STLL, CMT, C_AGT, F_AGT and EUI denote respectively plot











Ratios, degree of subdivision, level of accessibility, still, cement coarse aggregate, fine

aggregate and electricity use intensity.

Table 6.3: Pearson Correlation Coefficients for two sets of Indicators

PR SUB ACS STLL CMT C_AGT F_AGT EUI

PR 1

SUB -0.6846 1

ACS -0.1551 0.1406 1

STLL 0.3349 -0.2315 -0.0824 1

CMT 0.3542 -0.2425 -0.0798 0.9966 1

C_AGT 0.3581 -0.2447 -0.0791 0.9950 0.9998 1

F_AGT 0.3604 -0.2460 -0.0788 0.9938 0.9996 0.9999 1

EUI 0.2814 -0.2171 -0.0799 0.9360 0.9238 0.9202 0.9180 1

This table represents relationships between the indicators whether they are positively or

negatively correlated but these do not necessarily indicate the any statistical significance

of the coefficients, for which a Multiple Linear Regression Model is run with the two sets

of indicators proceeded by the objective to measure the dependency of the physiological

indicators on the morphological indicators. This objective is stemmed from thehypotheses that Bukit Panjang already has got its territorial shape so nothing to plan about

the arrangement of the land parcels rather how to make efficient the physiological process

taking place on the territory.

The multiple linear regressions equation therefore formulated as follows:

ii ACSbSUBbPRbaY ε ++++= *** 321

Where,

Yi = Dependent variables (physiological indicators)

a = Regression Constant

b1 , b2 , b3 = Co-efficients of explanatory variables

iε = Regression errors






Based on this equation, a Multiple Linear Regression Model has been run in STATA for

each dataset of physiological indicators and morphological indicators. The estimated

results are tested for statistical significance at 95% confidence level, which means that if

the estimated mean of the coefficients are within 95% confidence interval of a t

distribution, then the corresponding P-values are lower than 5%. The P-value is the

probability of seeing a result as extreme as can be found in a collection of random data in

which the variable had no effect. A P-value of 5% or less is the generally accepted, where

decision can be made to accept/reject the null hypothesis that a coefficient is zero. If the

P-value of a coefficient is lower than 0.05, the null hypothesis can be rejected, and can be

concluded that the coefficient has reasonable effect on the dependent variable.

Constant values are excluded from the regression equation which can be explained this in

this way that, when the values of all the variables will be zero, the value of Y would be

equal to the constant which is not expected; therefore, running the models with the

constant term can be erroneous. As calculated in STATA, the multiple linear equations

have become as follows:

(i) STLL = 694468.5*PR – 216474.5*SUB – 154887.8*ACS

Where the P-values for PR, SUB and ACS are respectively 0.000, 0.403 and 0.168

(significant values therefore respectively 1, 0.597 and 0.832) with R2

value and Adjusted

R2

are 0.1888 and 0.1822.

(ii) CMT = 2192165*PR – 757032.8*SUB – 474797.9*ACS


(corresponding significant level are 1, 0.668 and 0.839) with R2 value and Adjusted R2 are

0.2033 and 0.1968

(iii) C_AGT = 5930590*PR – 2089239*SUB – 1277210*ACS







(significant level therefore 1, 0.683 and 0.841) with R2

value and Adjusted R2

are 0.2062

and 0.1998

F_AGT = 4651046*PR – 1657359*SUB – 998256.7*ACS

The P-values for PR, SUB and ACS are respectively 0.000, 0.309 and 0.159 (the

significant level are then 1, 0.691 and 0.841) for the regression equation with R2 value and

Adjusted R2 are respectively 0.2079 and 0.2014

The last regression equation is correlating electricity use intensity with the selected

morphological indicators which found as follows,

EUI = 114.99*PR – 53.71*SUB – 22.22*ACS

With the P-values for the independent variables are 0.000, 0.305 and 0.328

(corresponding significant level are 1, 0.695 and 0.673) and containing R2

value and

Adjusted R2

are respectively 0.1343 and 0.1273

6.4 Discussion

Every regression equation assume physiological indicators as dependent variable found

and noted above shows that physiological indicators have a positive relationship with Plot

Ratio (PR) and negative relationship with the other two morphological indicators, namely

Degree of Subdivision (SUB) and Level of Accessibility (ACS). The P-values of SUB and

ACS are found to be higher that 5% whereas these should be 0.05 or lower for accepting

their influence on physiological indicators.

Again while considered Adjusted R2 value which exhibit the predictability of the model

should be close to 1 for making decision based on the analysis result but in all the four






equations the Adjusted R2

value is very low so the predictability is stumpy. So, the model

will not be effective for any decision making based on the result.

There may be several reasons for very low predictability of the model. These may include

simple issues like the selection of the indicators for measuring correlation is not well

justified, or may have multiple effects of same set of indicators on the other set of

indicators. After all the two set of indicators may not linear with each other. Another

practical reason for failure of the predicting a rational relationship between the two sets

indicators can be quoted here that all the physical indicators calculated here based on the

buildings properties resulting significant relationship only with plot ratio that contains the

building information only from the morphological set of indicators. Other two indicators

obviously represent the characteristics of land parcels but not linked with the buildings

material stock or electricity consumption therefore does not show any significant

relationship with the physiological indicators.

So, planning decision for Bukit Panjang for improving environmental performance based

on this research should focus on the individual analysis of the indicators merely on the

correlation analysis. In the future endeavors if more diverse physiological indicators like

household fuel consumption, material stock for road networks etc would be integrated themodel may show good predictability.





Recommending Proposals 7-1

Chapter 7

Recommending Proposal

From the previous chapter the findings can be summarized as follows:

i. The total built up areas is very low for Bukit Panjang with a significant

percentage is totally dedicated for road network. For smooth functioning, an

urban area should have 40% road network of the total area where Bukit Panajng

has 39% which is a very strong indication of good urban planning. The total area

dedicated for buildings is only 14% of the total study area which implies that the

area is developed compactly and less convoluted.

ii. The plot ratio or building density mapping of Bukit Panjang indicates the

overall scenario of Singapore as part of the master plan 2003 (which

designates Bukit Pangang as mainly residential and nature reserve) which

explicitly represents the Government’s wholehearted effort to make

Singapore a garden city by preserving land horizontally for green and intensifying

development vertically. However, the plot ratios again can not be said so high

compared to other dense and compact cities like New York Manhattan because of

relatively small population size of Singapore.

iii. The degree of subdivision is also not so high because of compact settlements;

only subdivisions are higher where the individual landed properties are

concentrated. One of the main subdividing elements is the road hierarchies;

however, the road networks have not subdivided the land parcels in Bukit Panajng

because most of the HDB housing estates have only access way to get out from

the boundary which is absent in case of individual housings.

iv. In case of the granular index based on the GFA, the study area is composed of

heterogeneous grain sizes therefore it can be assumed that the low storied






buildings behind the tall buildings may face less exposure to sunlight, air

circulation and sound transmission, but in this case the high density development

also has made it possible to have less effect due to varied grain sizes.

v. Most of the terrace houses are far from the top hierarchy road network, it can be

hypothesized that people who live in terraced houses want to live with some kind

of tranquility which can be ensured partly by living far from the roads to avoid

noise. Therefore, there may a car dependency be observed. But from sustainable

township viewpoint car dependency should be reduced so concentrations of

terraced houses are not advisable.

vi. The physiological indicators all are related to the buildings’ consumptions and

stocks that are positively correlated with the buildings height and area, therefore

less significant with the other non-building morphological indicators. Two

physiological indicators show different efficiency rates for same building

typologies. Where the terrace houses show materially efficient, they appear

inefficient for electricity consumption. This is a very crucial planning issue to

trade off as still there are still some proposed building lots catered for future

terraced housings. It is also found that terraced houses cause higher degree of subdivision as well as higher intensity of electricity use.

vii. The material flow has been only considered in terms of their density or stocks

in various buildings but the materials must have an end use which is not

included in the analysis due to unavailability of end use data.

The above proposals have included the obvious features of built urban environment that

deal with the critical tasks for the urban planner and policy makers to address in planning

or policy making. The most important part of dealing with the built urban environment is

to take corrective measures so that the built morphological characteristics can have less

impact on the environment. Therefore some proposals can be drawn towards the






sustainability of the environment of Bukit Panjang based on the findings which are

discussed below.

The plot ratio for Bukit Panjang is already planned by the Urban Redevelopment

Authority therefore planning decision should focus on the building functions as to reduce

their impact on the environment by energy modeling and rational calculation of building

materials. As the building density positively correlated with material intensity and

electricity consumption and as electricity consumption is the only static source of urban

heat island, building technologies should adopt to reduce dependency on air cooling

appliances at the building architecture level. On the other hand, selecting materials for

building should consider the efficiency at the end-use level as each building has its life

time and after that time the building may need reconstruction. This process must require

putting material stock on the same land unit. In addition, wastes can be produced within

the lifecycle of buildings, during the construction, modification and demolition phases

which become serious environmental problems in many countries.

The primary environmental target regarding these two physiological consumptions of

buildings should be the prevention and reduction of construction waste generation and

reducing electricity consumption. One of the optimum solutions to reduce the materialintensity in Bukit Panjang can be the recover and re-use of the demolished materials in

reconstruction process in future. Policies to reduce the electricity use intensity should be

accompanied by the adoption of technologies to reduce the impact of high electricity and

fuel consumption. Though the effects and diversities of vehicular fuel consumption have

not been covered in this study; a detailed investigation for the environmental effects of

vehicular fuel consumption in Bukit Panjang should be carried out.

Land allocations for individual terrace housing result more subdivisions of the

corresponding land accompanied by more land requirements for their accessibility. The

scarce land for Singapore therefore is not suitable for allocating to development of landed

properties like terrace houses. The accessibility required for the terrace houses also

subject to supply of more construction materials like gravel, asphalt may result inducing






low albedo5

which again exaggerate the ‘urban heat island’. On the electricity

consumption site the indicator used here electricity consumption per unit area shows the

higher value for the terrace houses. Thus, in terms of electricity supply terrace housing is

not advisable as Singapore has to spend a high premium to produce electricity from

natural gas which is comparatively environment friendly electricity source in Singapore.

The government of Singapore is already largely engaged with tree plantation and

increasing green coverage over the Singapore which can be multiplied by increasing

green plot ratio (Lay, 2003) in the highly dense residential areas. This can be enhanced by

promoting greening the roof top as well as vertical gardening, façade and balcony

planting. The urban park planning can be the most effective approach for not only

absorbing the CO2 but also by providing shade so that less solar radiation can reach the

building surfaces which causes further worsening the heat situation of urban environment.

National Parks Board of Singapore is charged to promote and enhance green coverage by

implementing opens space and park connecting plan for Singapore. Singapore

government’s long time efforts to build Singapore have attenuated the environmental

impact of anthropogenic energy consumptions to a remarkable limit.

Government can think economic incentives for materially efficient buildings to promotematerially efficient buildings but the problem of inflation in status quo may hinder the

positive effects of economic incentives for resource efficient buildings. The purposes of

buildings again should be considered if government really thinks about the economic

incentives for the improved building technology. This is because a building might have

living or financial investment option in which case the latter one will not be purposeful.

Finally, for sustainability of an urban environment, an integrated effort by the authorities

e.g. URA, SLA, BCA and Singapore power authority is needed to generate a

multipurpose valid and quality database for evaluating the environmental performance of

various urban infrastructures ranging from the morphological properties to physiological

5 Albedo refers to the ability of a surface to reflect solar radiation but it differs from the reflectivity as it

accounts all kind of incoming radiation to the surface. The asphalt has low albedo value range 0.05-0.20

where grass has high albedo value of 0.25-0.35. (Dhakal, Shobhakar)






attributes. And more research regarding the material and energy flows in urban

environment should be carried out to find out the efficient metabolism process. Recently,

a research wing is established at the School of Design and Environment of National

University of Singapore named as ‘Center for Sustainable Asian Cities’, where some

researches on the industrial ecology is going on. Industrial ecology is the field of science

that deals with the material and energy flow through an urban and industrial system. As

the name suggests, the principles of this studies are the natural ecological rules, i.e.

closing the energy and material loop.





Conclusion 8-1

Chapter 8

Conclusion

Urbanization takes place in terms of spatial, temporal and demographic change associated

with modification and generation of spatial form, the changes in physical consumptions

which ultimately determine the performance of the environment. To find the relationship

between the urban form and its physiological process has been the main focus of this

research to ascertain the environmental analysis for the selected study area, Bukit

Panajng, a new town of Singapore planned for residential and nature reserve. Two sets of

indicators namely morphological and physiological have been used to see their correlationby multiple regression analysis. Morphologically Bukit Panajng has been analyzed by the

plot ratio of land parcels, degree of subdivision of the same parcels, buildings grain sizes

based on its gross floor area and the parcels’ level of accessibility. To measure the effects

of these morphological characteristics on the physiological process the material intensity

as construction materials’ stock in the buildings of Bukit Panjang and electricity use

intensity as electricity consumption per unit area of buildings have been used as

physiological indicator.

The physiological indicators used here have not shown so remarkable correlation with the

morphological indicators except plot ratio therefore planning decision based with the

multiple objectives should not be practiced in this case; rather planning focus should be

based on the individual indicators’ responses to the built environment. Morphologicall,

Bukit Panjang has indicated the Singapore’s government’s intention to make this area as a

compact residential area with natural vegetated area by allowing steady building density

over the maximum plots of the area and providing almost strong accessibility for the plots

at the same time less degree of subdivision. In terms of physical consumptions, the land

parcels containing landed properties or terrace houses have shown the highest rate of

aggregate consumption. These morphologies have appeared as more land subdividing and

irrational in respect of Singapore’s land crisis and aim to be city in garden.





Conclusion 8-2

Singapore is a small island city; due to have very good per capita income and being

strategically a very good business hub, the city’s metabolism process is also excessively

high which eventually gives rise to the effect of heat island, environmentally an

unexpected event for healthy and sound urban life. To attenuate this effect would require a

rational selection of material for building construction and electricity i.e. energy efficient

building operation. In this research a very small part of Singapore’s metabolism process

has been considered by relating with the morphology; future extensive studies which may

account more energy and material flow in Singapore’s urban environment should give a

platform for sensible planning decision to ensure a livable community by optimum

resource allocation for urban buildings and infrastructures. However, it is not wise to

make any decision about the sustainable performance of Singapore’s urban environment

without expanding the analysis towards other dimensions like ground water availability,

the albedo values across the island as well as more extensive behavior of urban energy

and material consumption.



Morphological and Physiological Analysis for Measuring Urban Environmental Performance: A Case study

of Bukit Panjang New Town

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