Growing Green - Yufei Li

Liberating Digital Design Research Seminar

GROWING GREEN STRATEGY Melbourne CBD

RMIT University Landscape Architecture Seminar Leader: Dr Ata Tara Semester 02- 2021

Prepared by : Yufei Li 10/14/2021

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RMIT University Landscape Architecture Design Research Seminar - Liberating Digital Seminar Leader: Dr Ata Tara Semester 02 - 2021

Introduction

Main Focus: Urban Heat Island

Study Area: Melbourne CBD

Urban Heat Island effect and Nature-based Solution

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Composition Landcover and Landuse

Landform

Hydrology

Vegetation

Existing Green Roof and Planting Schedules Public Transport Network

Roof Types

Solar Radiation

Heat Vulnerability Topography

<6-16> <6-7> <8> <9> <10> <11> <12> <13> <14> <15> <16>

Relationship

Key Elements of Urban Heat Island: Axonometric Visualization

Hydrology and Vegetation

Public Transport network and Vegetation

Vegetation and Surface Temperature

Vegetation and Heat Vulnerability

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Generation

Define Focus Area

Visibility Analysis

Visibility Index

Potential Green Roof Rating

Proposal and Intervention

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Conclusion

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CONTEXT

The document contains a series of mappings, representations, spatial analysis and modelling created with the collection of geospatial data and the support of ArcMap and ArcScene. Based on the analysis and interpretation of the data through these mappings and visualizations, the document seeks to explore where it is suitable to renovate buildings with high-quality green roofs to reduce the impact of the urban heat island effect.

The design research process is based on three different phases: composition, relationships and generation.

Main Focus: The Urban Heat Island Temperatures in many urban areas are warmer than their rural surroundings.

This phenomenon is known as the ‘Urban Heat Island’ which refers to temperature differences attributable to urbanisation.

Urban heat islands can have multiple impacts on human health, resource use, and air quality. Thus, we must act now if we are to maintain and improve our city’s liveability.

Research Question The research will be carried out from several questions. From introducing an overview of Melbourne CBD to finding out the relationship between the key elements that possibly affect the urban heat island effect, and finally calculating the most suitable buildings for the green roof scheme through visibility analysis.

1. What is the landscape condition of Melbourne CBD? 2. What cause the urban heat island effect?

3. If the aim is to transform the roofs of Melbourne’s CBD into green roofs, where are the most visible?

Introduction

This document discusses how to use Naturebased Solution to mitigate one of the effects of climate change on a high-density city: the heat island effect.

RESEARCH TOPIC Nature-Based Solution

Relationship Landform Landcover and Landuse Hydrology

Composition

Transportation Network

Heat Vulnerability Index

Existing Greening Roof Solar Radiation Focus Area

Methodology

Choose buildings higher than 180m

The information and data collected mainly by Data. Vic has been studied and visualised to establish a system in GIS. Mappings and visualizations have been created in ArcGIS and 3D models have been generated from ArcScene.

Vegetation

Visibility Analysis

Generation

Growing Green

Potential Greening Roof 3

Melbourne CBD

Study Area

Melbourne CBD is the central built up area of the city of Melbourne, Victoria, Australia, centred on the Hoddle Grid.

Carlton North

Our climate in Victoria has already warmed by 1°C. This is putting Melbourne’s coveted liveability in danger.

Melbourne residents have observed the impacts of climate change and are concerned about future impacts

Heatwaves

North Melbourne

Carlton

Docklands South Wharf

East Melbourne

Melbourne

In 2018 Melbourne experienced a 1 in 1000 year rainfall event with 50 mm of rain falling in 15 minutes. This resulted in flash flooding, train lines suspended and power outages across the city.

Melbourne will experience more severe rainfall events, increasing the likelihood of flooding and storm surge.

By 2050 sea levels will rise by 24 cm on 1990s levels.

Southbank

Bushfire smoke South Yarra

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72%

63%

64%

71%

71%

Rainfall

West Melbourne Melbourne CBD

68%

Melbourne is experiencing hotter days. We currently average 11 days greater than 35 degrees. By 2050 we will experience an average 16 days greater than 35 degrees.

Kensington

Port Melbourne

Residents’ Perceptions of Climate Change

Melbourne is experiencing hotter days, bushfire smoke, more intense storms and flooding. The disruption caused by these impacts is already affecting homes, businesses and the natural environment.

Parkville

Flemington

Climate Change in Melbourne CBD

In January 2020 Melbourne’s air quality was the worst in the world due to smoke from bushfires.

Victoria has had longer fire seasons since the mid-1990s and fire days are projected to increase by 42 per cent per year in Melbourne by 2050.

Sourse: Sustainability Victoria

Main Focus: The Urban Heat Island

Nature-based Solution

Like many other cities, Melbourne faces continued pressure from increasing urbanisation. Rapid population growth and urban development have transformed natural environments into areas of highly engineered infrastructure. Heat generation from cars, industry and commerce, coupled with the retention of solar energy by buildings and paved surfaces, caused the urban heat island effect.

Through the nature-based solution, Melbourne can decrease the impact of the urban heat island effect on our city. Now, Melbourne city council has developed a series of nature-based solutions to ensure the sustainable development of Melbourne.

Over the past fifty years Melbourne’s CBD temperatures have been creeping up by 0.2 degree per decade since 1950s’.

Now, Melbourne City Council has found temperature variations of up to 4 degrees between the city centre and suburbs because of the urban heat island effect.

Nature-Based Solution

Urban Heat Island effect and Nature-Based Solution

1. Open Space Strategy (2012-2027) Aim: Increase green space 2. Urban Forest Strategy (2012-2032) Aim: Double canopy cover 3. Urban Ecology Strategy (From 2016) Aim: Enhance biodiversity 4. City as a Catchment Strategy (From 2012) Aim: Increase storm water harvesting 5. Green Our City Strategy (2017-2021) Aim: Create more green infrastructure

Legend Study Area Boundary Tree Canopy

Legend Legend Study Area Boundary

Tree Density (Dense)

Legend Tree Density (Medium)

StudyCanopy Area Boundary Tree

Study Area Boundary Tree Density (Scattered)

Canopy (Dense) Tree Density

Tree Canopy

Tree Density (Dense) (Medium)

Tree (Dense) RoadDensity Corrdiors

(Medium) Tree Density (Scattered)

Tree Density (Medium) Rivers

Tree Density (Scattered)

Tree Density (Scattered)

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Road Corrdiors Road Corrdiors

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Landcover 2015 Class Name Built environment Conifer plantation

Composition

Disturbed ground Dryland cropping Exotic pasture/grassland Hardwood plantation Horticulture / irrigated pastures and crops Mangrove vegetation Native pasture / grassland

Landcover and Landuse

Native scrubland Natural low cover Other exotic tree cover Saltmarsh vegetation Scattered native trees Treed native vegetation Urban area Water Wetland - perennial Wetland - seasonal

° Your Mapping Question: What is the landcover in Melbourne CBD? DATA SOURCES • Collection of data LANDCOVER_2015 from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

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CONCLUSION/FINDING Melbourne CBD is almost covered by the built environment. Some parks are located to the north and southwest of Melbourne CBD and are covered with vegetation.

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Composition

Legend Study Area Boundary

Landuse 2014 Type Medical place General Industrial Development Site Residential General Service Transportation Facilities Commercial Creative Industries Car Park Mixed Use Occupation Bars and Restaurants Office Premises Parks and Gardens Reserved Land Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community

° Your Mapping Question: What is the landuse in Melbourne CBD? DATA SOURCES • Collection of data LANDUSE_2014 from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

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CONCLUSION/FINDING Most of Melbourne CBD is occupied by mixed-use buildings. As the core of Greater Melbourne’s metropolitan area, and is a major financial centre in Australia and the Asia-Pacific region, Melbourne CBD has a large amount of office and commercial space.

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As can be seen from the map, there is almost no green space in Melbourne CBD.

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Landform Type

Legend Study Area Boundary City Footprint

Landform Type Central sunklands Dissected landscapes at a range of elevations Engineered coast (Port Melbourne) Hills and low hills Landscapes below 500 m of low relief Low coasts (wetlands, tidal reaches)

Landform and Soil Type

Composition

Volcanic plains

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Legend

Legend 10m Contour

City Footprint

Soil Type

Study Area Boundary

landform Value

Study Area Boundary

Legend

Study Area Boundary

High : 65.251

Water Deep Stratified Sand/ Silt/ Clay/ Gravel Duplex - ClaySilt then Clay

landform

Medium to Heavy Textured Clay with some Sand Sandy Loam Shallow Heavy Textured Clay

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Mapping Question:

Silt

High : 65.251

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0.275

Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community

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CONCLUSION/FINDING

What is the Landform in Melbourne CBD? 1.1

Classification

10m Contour

Value

1.65

2.2 Miles

DATA SOURCES • Collection of data GMU250 from the official Data.Vic platform.

Analysis and categorization of the data by Arcmap.

• Collection of data SOIL_TYPE from the official Data Vic platform.

Analysis and categorization of the data by Arcmap.

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1.1

Soil Type

Low : 0.1

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The majority of Melbourne CBD are predominantly flat throughout the central and southern areas, with some extremely slight slopes throughout and then a more steep slope to the outer edges and moving towards the eastern and northern areas of the suburbs.

Relationships Hydrology

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Mapping Question:

CONCLUSION/FINDING

What is the hydrology in Melbourne CBD?

These flow routes are derived from the shapefile of Melbourne DEM with buildings using ESRI Spatial Analyst stream order tool. The GRID_CODE field represents stream order.

DATA SOURCES • Collection of data from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

• Collection of data from the ArcGIS Online. Analysis and categorization of the data by Arcmap.

The map clearly shows that the main stream is located on the main street in the middle of Melbourne CBD, which is Elizabeth street. I found data of the most frequent flooding on ArcGIS Online, which is also the Elizabeth street.

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Composition

Legend

Vegetation

Study Area Boundary

Oak Fig

Tree Density

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Tree Canopy

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CONCLUSION/FINDING

What types of vegetation can be found in Melbourne CBD?

Except for the vegetation on both sides of the streets in Melbourne CBD, there is relatively little vegetation in other places. Especially the main traffic road in the middle of Melbourne CBD, which is Elizabeth street, has the least vegetation.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

The main street tree is plane, which is one of the native plants.

Jacaranda

Dense

Apple Tree

Japanese Zelkova

Medium

Locust

Gum

Scattered

Myrtle

Poplar

Palm

Maidenhair Tree

Plane

Nettle Tree

Elm

Peppercorn Tree

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Mapping Question:

Common Name

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Composition Study Area Boundary

Tree Planting Zone Schedules Complete

Legend

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Study Area Boundary

Years 1 - 4

Existing Green Rooftop

Years 5 - 7

Existing Rooftop Garden

Years 8 - 10

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Mapping Question:

CONCLUSION/FINDING

Where are the existing green roofs in Melbourne CBD? What is the planting schedule?

There are some green roofs in Melbourne CBD. Some are open to the public, some are semi-public. But the number of these existing green roofs is small, so the positive impact on the environment is limited.

DATA SOURCES • Collection of data from the City of Melbourne Open Data platform.

Analysis and categorization of the data by Arcmap.

• Collection of data Tree planting zone schedules, with years (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

In the urban forest strategy proposed by Melbourne City Council, streets in each precinct have a planting schedule. The planting schedule is based on factors such as the useful life expectancy of existing trees, the existing canopy cover, and the hot streets shown in thermal imaging,etc.

As can be seen from the map, the planting schedule in Melbourne CBD is mainly within 5-10 years.

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Existing Green Roof and Planting Schedules

Legend

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Public Transport Network

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Mapping Question:

CONCLUSION/FINDING

Where is the public transportation in Melbourne CBD?

One of the reasons for the urban heat island effect is population activity. Where public transportation is well developed, it means more people flow.

DATA SOURCES • Collection of data PTV_PUBLIC_TRANSPORT from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

The map shows the public transport network in Melbourne CBD. Vegetation should be planted around public transportation to mitigate the urban heat island effect.

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Composition Legend

Rooftop Type

Study Area Boundary

Roof Type Classification Flat Gable Hip Pyramid Shed

Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community

° Mapping Question:

CONCLUSION/FINDING

What are the roof types of buildings in Melbourne CBD?

Different roof types determine the possibility that the roof can be transformed into a green roof. It is easier to grow plants on flat roofs.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

It can be seen from the map that most of the roofs in Melbourne CBD are flat roofs.

These roofs are more suitable for turning into green roofs.

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Pyramid

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Shed

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Surface Temperature Composition

Legend Study Area Boundary

Surface Temperature Value

Low

Solar Radiation

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Mapping Question:

CONCLUSION/FINDING

What is the solar radiation in Melbourne CBD in summer and winter?

Light intensity tends to be greater at height than at ground level. Due to the large number of skyscrapers in Melbourne CBD, and increased reflection from adjoining building and surfaces (such as glass and light-coloured walls), solar radiation in most parts of the Melbourne CBD is very high.

DATA SOURCES • Collection of data from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

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Solar Radiation (Winter)

Very high

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Study Area Boundary

Solar Radiation (Summer)

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Study Area Boundary

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However, there are some roofs and walls that may receive significantly less solar radiation, due to intense shading by nearby high-rise buildings.

From the surface temperature data, it can be known that the temperature in the middle of Melbourne CBD is the highest.

There are many possible reasons, such as less vegetation, and dense public transportation learned from the previous map.

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Composition Study Area Boundary City Footprint

Heat Vulnerability Index Very High High Moderate Low Very Low

°

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Mapping Question:

CONCLUSION/FINDING

What is the heat vulnerability index in Melbourne CBD?

This data presents areas of heat vulnerability in Melbourne CBD. Indicators of exposure, sensitivity and adaptive capacity were used for calculating overall heat vulnerability index.

DATA SOURCES • Collection of data MELB_Heat_Vulnerability_Index_SA1_2018 from the ArcGIS Online. Analysis and categorization of the data by Arcmap.

The original heat vulnerability index (HVI) is represented by a scale of 1 to 5 based on quintiles, with 1 representing very low exposure, very low sensitivity or high adaptive capacity and 5 representing very high exposure, very high sensitivity or low adaptive capacity.

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Heat Vulnerability Index

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Composition Topography

Legend

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Mapping Question:

CONCLUSION/FINDING

Where are the high-rise buildings in Melbourne CBD?

The high-rise buildings are mainly on the east and west sides of Melbourne CBD. Melbourne’s traffic arteries which are the Swanston Street and the Elizabeth street, the buildings on both sides are low in height.

Study Area Boundary

DSM Value

High : 264 Low : 2

DATA SOURCES • Collection of data Existing Melbourne Model from the official Data.

Vic platform. Analysis and categorization of the data by ArcScene.

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Legend Study Area Boundary City Footprint

Heat Vulnerability Index Heat Vulnerability Index Very High High Moderate Low Very Low

Legend Area Boundary SolarStudy Radiation (Summer)

Solar Radiation (Summer) Very high High Moderate

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Legend

Relationship

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Bus Route Tram Route Train Track

Axonometric Visualization

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Melbourne DEM

Legend Value

Existing Roof High : Greening 302.875 Study Area Boundary Low : 1.8 Green Rooftop Existing

Existing Rooftop Garden

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Hydrology

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Axonometric visualization Mapping Question: What kind of elements that could possibly impact the urban heat island effect?

What kind of elements could help me analyze where to transform into green roofs?

DATA SOURCES • Collection of data from the official Data.Vic platform. Analysis and categorization of the data by ArcScene.

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Relationship Hydrology and Vegetation

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Mapping Question:

CONCLUSION/FINDING

What is the relationship between streams and vegetation in Melbourne CBD?

The street with the most frequent flooding coincide with the street with the least vegetation.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

•

Collection of data from the ArcGIS Online. Analysis and categorization of the data by Arcmap.

0.6 Miles

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Mapping Question:

CONCLUSION/FINDING

What is the relationship between vegetation and public transport network in Melbourne CBD?

In order to reduce the negative effects of public transportation, vegetation are widely planted around public transportation. But there are still some places with less vegetation.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

•

Public Transport network and Vegetation

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Collection of data PTV_PUBLIC_TRANSPORT from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

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Relationship Vegetation and Surface Temperature

Legend

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Study Area Boundary Tree Density (Medium) Tree Density (Scattered) Tree Canopy

Surface Temperature Value

High Low

Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community

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Mapping Question:

CONCLUSION/FINDING

What is the relationship between surface temperature and vegetation in Melbourne CBD?

As it is possible to see from the mapping, vegetation is directly related to surface temperature. Areas with more vegetation are low temperature. Conversely, the higher it is.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

•

Collection of data from the ArcGIS Online. Analysis and categorization of the data by Arcmap.

Relationship Study Area Boundary Tree Canopy Tree Density (Dense) Tree Density (Medium) Tree Density (Scattered)

Melbourne Heat Vulnerability Index Very High High Moderate Low Very Low Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community

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Mapping Question:

CONCLUSION/FINDING

What is the relationship between surface temperature and vegetation in Melbourne CBD?

Through this map, it can identify the relationships between vegetation and heat vulnerability index (HVI).

Vegetation is related to reduced HVI.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

•

Collection of data MELB_Heat_Vulnerability_Index_SA1_2018 from the ArcGIS Online. Analysis and categorization of the data by Arcmap.

Vegetation and Heat Vulnerability

Legend

Dark red areas which is around the Swanston street and Elizabeth street have the least vegetation and the highest vulnerability to heat.

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Study Area Boundary High Heat Vulnerability

Melbourne Heat Vulnerability Index Very High High Moderate Low

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Heat Vulnerability Index

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Define Focus Area

Generation

City Footprint

Study Area Boundary Very High Solar Radiation High Heat Vulnerability Tree Canopy Tree Density (Dense)

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Tree Density (Medium)

Study Area Boundary Very High Solar Radiation

Solar Radiation (Summer)

Tree Density (Scattered)

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City Footprint

Moderate Low Very Low

Solar Radiation (Summer)

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Mapping Question:

CONCLUSION/FINDING

Which are the potential focus areas?

Heat vulnerability, Solar radiation and vegetation cover the mian factors that influence the urban heat island effect.

DATA SOURCES • Collection of data Tree Canopies 2011 (Urban Forest) from the City of Melbourne Open Data platform. Analysis and categorization of the data by Arcmap.

• Collection of data TREE_DENSITY from the official Data.Vic platform. Analysis and categorization of the data by Arcmap.

• Collection of data MELB_Heat_Vulnerability_Index_SA1_2018 from the ArcGIS Online. Analysis and categorization of the data by Arcmap.

For this reason, I drew these abstract boundaries and I overlayed them to reveal hidden relationships and points of contact between them.

This process helped me identify potential risk areas and therefore potential areas of generation and intervention

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0.4 0.4 Miles Miles

Legend

10

!

! !! !

Study Area Boundary

11

!

!

!

Can be seen by 2 points

9

Can be seen by 3 points

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City Footprint

! !

°

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6

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8

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Visibility Analysis

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Building 1

! ! ! !

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1

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Generation

!

Viewpoints Can be seen by 1 point

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2

! !! !

Legend Study Area Boundary !

Viewpoints Can be seen by 1 point Can be seen by 2 points City Footprint

°

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Building 2

°

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Mapping Question:

Why Visibility is important:

If the aim is to transform the roofs of Melbourne’s CBD into green roofs, where are the most visible?

The purpose of the green roof is not only to mitigate the urban heat island effect, but also to create more public space for people in this high-density city.

Green roofs can be used and seen by people who live in high-rise buildings to improve their mental health.

0.2

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Legend

Legend

Study Area Boundary

°

0

0.05

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Study Area Boundary

Viewpoints

!

Viewpoints

Can be seen by 1 point

Can be seen by 1 point

Can be seen by 2 points

Can be seen by 2 points

City Footprint

City Footprint

0.2

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°

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Building 3

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Building 4

Visibility Analysis

Generation

!

Legend Study Area Boundary

Legend !

°

0

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Building 5 Mapping Question:

24 If the aim is to transform the roofs of Melbourne’s CBD into green roofs, where are the most visible?

!

Viewpoints

Study Area Boundary

Can be seen by 1 point

viewpoint8

Can be seen by 2 points

Can be seen by 1 point

Can be seen by 3 points

Can be seen by 2 points

Can be seen by 4 points

City Footprint

City Footprint

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°

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Building 6

0

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Legend

Legend

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Study Area Boundary

Viewpoints

!

Viewpoints

Can be seen by 1 point

Can be seen by 1 point

Can be seen by 2 points

Can be seen by 2 points

Can be seen by 3 points

Can be seen by 3 points

City Footprint

City Footprint

0.2

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Building 8

Visibility Analysis

Building 7

0

Generation

Study Area Boundary !

Legend

Legend

Study Area Boundary !

°

0

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Building 9

Study Area Boundary

Viewpoints

!

Viewpoints

Can be seen by 1 point

Can be seen by 1 point

Can be seen by 2 points

Can be seen by 2 points

Can be seen by 3 points

Can be seen by 3 points

City Footprint

City Footprint

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°

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Building 10

Mapping Question: If the aim is to transform the roofs of Melbourne’s CBD into green roofs, where are the most visible?

25

Legend

Legend

Study Area Boundary

°

0

0.05

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Study Area Boundary

Viewpoints

!

Viewpoints

Can be seen by 1 point

Can be seen by 1 point

Can be seen by 2 points

Can be seen by 2 points

Can be seen by 3 points

Can be seen by 3 points

City Footprint

City Footprint

0.2

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°

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Building 11

0

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Building 12

Visibility Analysis

Generation

!

Legend

Legend

Study Area Boundary !

°

0

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Building 13 Mapping Question:

26 If the aim is to transform the roofs of Melbourne’s CBD into green roofs, where are the most visible?

Study Area Boundary

Viewpoints

!

viewpoint9

Can be seen by 1 point

Can be seen by 1 point

Can be seen by 2 points

Can be seen by 2 points

Can be seen by 3 points

Can be seen by 3 points

City Footprint

City Footprint

0.2

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°

0.4 Miles

Building 14

0

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! ! !! !

! ! !

! ! ! !

! ! !

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!

!

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! !!

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! ! ! !

Generation

! ! ! !

! ! !

!

! ! ! ! ! !

!

Legend

! !! !

Study Area Boundary !

Viewpoints

Visibility Index Value

Visibility Index

!

High Low

° Mapping Question: What is the visibility Index in Melbourne CBD? DATA SOURCES • Collection of data Existing Melbourne Model from the official Data.

Vic platform. Analysis and categorization of the data by ArcScene.

• Merge multiple rasters (visibility analysis)

0

0.05 0.1

°

0.2

0

0.050.3 0.1

0.2 0.4

Miles

0.3

0.4 Miles

CONCLUSION/FINDING The visibility Idex mapping has been generated through a process of visibility analysis and raster combination: Merge of the visual analysis of the high-rise buildings (height higher than 170m) in focus areas.

As it is evident from the mapping, the most exposed area is concentrated on the main corridor which is the Swanston Street.

Red indicates high visibility and green indicates low visibility.

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Generation Potential Green Roof

Legend Study Area Boundary Excellent Greening Roof Rating Good Greening Roof Rating Moderate Greening Roof Rating City Footprint

°

28

Mapping Question:

CONCLUSION/FINDING

What is the suitability of greening roofs?

The visibillity index raster has been reclassified into a scale from 1 to 5.

1 (Lowest visible - Lowest greening roof rating) and 5 (Highese visible - Excellent greening roof rating).

DATA SOURCES • Reclassified rsater (Visibility Index) • Choose the building based on the reclassified raster

By analysing the urban footprint and visibility index, I identified those buildings by excellent greening roof rating, good greening roof rating and moderate greening roof rating. This means these buildings are more suitable for conversion to greening roofs.

°

Esri, HERE, Garmin, (c) OpenStreetMap contributors, and the GIS user community 0 0.05 0.1 0.2 0.3 0.4 Miles

0

0.05 0.1

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Generation Potential Green Roof Legend Excellent Greening Roof Rating Good Greening Roof Rating Moderate Greening Roof Rating Tree Canopy

DEM Value

High : 52 Low : 0

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Design Proposal

Generation

Design Proposal Growing Green Strategy

Growing Green Benefits

Green roofs are appealing to add green infrastructure to a city because they can be included on new buildings or retrofitted onto existing buildings. They are being used to compensate for the loss of urban greenery, provide localised cooling and reduce the impact of the urban heat island effect.

There is a range of benefits, outlined below, that can potentially be provided by green roofs. Some provide benefits to the public at large and some only benefit the building owner or occupants.

Green roofs can take many forms: 1. Green Roof A vegetated landscape built up from a series of layers that are installed on a roof surface.

2. Community Roof Garden A green public space to meet people’s daily social needs.

3. Edible Roof Garden Food production

1. Cooling a city – urban heat island effect Temperatures can be reduced by covering a roof with a layer of vegetation that shades building materials which would otherwise absorb heat.

2. Cleaning the air Green roofs can contribute to the removal of gaseous pollutants from the air, although their effectiveness varies with plant species and area of cover.

3. Stormwater management Green roofs absorb and retain rainwater and can be used to manage stormwater runoff in urban environments.

4. Aesthetics, open space and urban food production Green roofs can increase amenity and provide opportunities for food production, recreation, relaxation or commercial ventures.

Green Roof 30

Community Roof Garden

Edible Roof Garden

Conclusion

References

Hot weather is a threat to human health.

Increased vegetation can help reduce temperatures, minimise the impact of heatwaves, with the potential to lower heat related death rates.

City of Melbourne 2012, Open Space Strategy — Planning For Future Growth, City of Melbourne, viewed 22 August 2021, <https://www.melbourne.vic.gov.au/SiteCollectionDocuments/open-spacestrategy.pdf>.

Through the study of GIS, I investigat and overlay different elements that may affect the urban heat island effectallowed the proposition of growing green strategy for Melbourne CBD.

City of Melbourne 2014, DRAFT URBAN ECOLOGY AND BIODIVERSITY STRATEGY—The city as an ecosystem, City of Melbourne, viewed 23 August 2021, <https://participate.melbourne.vic.gov.au/ nature>.

City of Melbourne 2014, Growing Green Guide, City of Melbourne, viewed 23 August 2021, <https:// www.melbourne.vic.gov.au/SiteCollectionDocuments/growing-green-guide.pdf>.

Conclusion

Many cities around the world recognise the importance of having green infrastructure; that is, natural landscape assets, including green spaces and water systems. Green infrastructure includes trees, parks, water sensitive urban design (such as wetlands and rain gardens) and green roofs.

City of Melbourne 2012, URBAN FOREST STRATEGY, City of Melbourne, viewed 23 August 2021, <https://www.melbourne.vic.gov.au/sitecollectiondocuments/urban-forest-strategy.pdf>.

City of Melbourne 2014, Total Watermark–City as a Catchment, City of Melbourne, viewed 22 August 2021, <https://hdp-au-prod-app-com-participate-files.s3.ap-southeast-2.amazonaws. com/2915/6533/2611/total-watermark-update-2014.pdf>.

Dowling, J 2014, Melbourne city centre a death trap as heat-island effect takes its toll, The Age, viewed 3 September 2021, <https://www.theage.com.au/national/victoria/melbourne-city-centre-a-death-trap-asheatisland-effect-takes-its-toll-20140116-30xt8.html>.

Johnson, C 2014, Greening urban areas can help reduce future impacts of heatwaves, CSIROscope, viewed 3 September 2021, <https://blog.csiro.au/greening-urban-areas-can-help-reduce-future-impactsof-heatwaves/>.

Hurleya, J 2019, Urban Vegetation Cover Change in Melbourne, Victoria State Government environment, land, water and planing, viewed 15 September 2021, <https://www.planning.vic.gov.au/__ data/assets/pdf_file/0023/441464/Urban-Vegetation-Cover-Change-in-Melbourne-2014-2018_Final.pdf>.

Sun C 2019, Urban Vegetation, Urban Heat Islands and Heat Vulnerability Assessment in Melbourne, 2018, Victoria State Government environment, land, water and planing, viewed 15 September 2021, <https://www.planning.vic.gov.au/__data/assets/pdf_file/0018/440181/UHI-and-HVI2018_Report_ v1.pdf>.

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RMIT University Landscape Architecture Liberating Digital Design Research Seminar Semester 02 - 2020