Flooding Management and Response Plan for Greater Melbourne GEOM20013: Applications of GIS Assignment 4 10 June 2019
Authors: Tutorial Group 12 Ginnivan, P (910836)., Head-Gray, G (835825)., Morris, S (699182) Tutorial Group Thursday, 4.15pm (Group 12)
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TABLE OF CONTENTS Abstract ……………………………...…….3 Introduction…………………....………...4-6 Literature Review ……………...……...7 Methodology……………………….…….10-14 Hazard and Risk Maps………..……..15-24 Discussion ………………………..……….25 Recommendation ………………………..……….26-28 Conclusion ………………………………...29 Figure References ………....……….....30 Bibliography………………………….…...31 Appendix A………………………………...32 Appendix B………………………………...33-34
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ABSTRACT Floods are a natural phenomena that causes significant impacts on the communities, economy, built infrastructure and natural environments of Australia. From 1967 to 2013, the direct annual cost of flooding amounted to $943 million (Geoscience Australia). This, coupled with a long term economic and societal impacts and costs that consequent from flooding; it is imperative that responsible authorities pursue an adaptive flooding management approach to mitigate flooding disaster events.
The aim of this report is to provide the Victorian State Government emergency response and management plans for the Greater Melbourne region. The paper provides a synthesis of relevant literature on flood management and Geographic Information Systems (GIS) for flood risk analysis. By applying both sources of information and analysis, this paper explores the appropriate criteria, variables and parameters used in spatial analysis. These variable were provided with weightings to indicate levels of risk to potentially affected areas in the Greater Melbourne Region. With the use of digital elevation models (DEM) and data, flood hazard and risk maps were produced for the general public of Greater Melbourne and relevant authorities responsible for the safety and resilience of communities. This paper addresses the gap in research and risk management analysis for Greater Melbourne, as there is limited scholarly research in this region of Australia concerned with flooding events. The findings from GIS analysis and review of existing literature contributed to the recommendations for population movement, environmental impact statements, industry response plans and infrastructural management and protection plans. However, despite limitations of data availability and limited experienced in research and analysis, this report contributes to the gap in research and literature of flooding risk analysis and management for Greater Melbourne.
ABBREVIATIONS Abbreviation
Meaning
DEM
Digital Elevation Model
BOM
Bureau of Meteorology
GIS
Geographic Information System
LGA
Local Government Area
VICSES
Victorian State Emergency Services
SA2
Statistical Area 2
FHI
Flooding Hazard Index
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INTRODUCTION Flooding is a natural hazard experienced in Australia nation-wide (Melbourne Water, 2015). Such phenomenons in urban centres cause significant damage to communities, the natural environment, built environment and vital infrastructure networks (M. H., & Middelmann, M. 2007). In Victoria, flooding has many causal factors such as: heavy rainfalls over catchment areas, impervious surfaces, geology, riverine flooding, tidal influences, storm surges and increasing of sea levels due to climate change (M. H., & Middelmann, M. 2007). Flooding is an experienced and common phenomena for a large portion of Victoria’s population (Ladds, M., Keating, A., Handmer, J., & Magee, L. 2017). The tangible and intangible economic costs of flooding are known to be a significant impact on affected society and on government expenditure (Deloitte Access Economics, 2017); this can include costs of recovery of public infrastructure, transport reconstruction, homes and government supplementary funding such as emergency payments (Deloitte Access Economics, 2017). In Victoria, the predominant hazards in terms of costs are storms, floods, cyclones and bushfires. Since 2000, Victoria has experienced 40% of Australia’s total disaster loss (Handmer, J., Ladds, M., & Magee, L. 2018). Moreover, the economic costs of natural disasters for Australia will increase to $39 billion per year by 2050 (Deloitte Access Economics, 2017). However, with appropriate knowledge applied for risk management schemes and protocols for emergency response, such impacts can be mitigated (Climatexchange Scotland, 2016). The purpose of this report is to provide the Victorian State Government recommendations on risk management strategies and emergency response plans in areas within Greater Melbourne (Figure 1). The selection site of the Greater Melbourne region for this report is to reduce crisis as seen over the past few years (Figure 2, Figure 3); for example, the flash flooding of inner suburbs and coastal regions part of Greater Melbourne in December 2018 (Herald Sun, 2018). Furthermore, this report explores the risk of flooding inundation due to rising sea levels for the coastal regions of the Greater Melbourne Region, as seen at high levels of risk from findings. Analysis based on Geographic Information System (GIS) for flood hazard modelling, has been used to understand and identify which populations by Local Government Areas (LGAs) may be exposed to flood hazards at high levels of risk. The methodology of analysis and findings, , found in later sections of this paper, provided sound conclusions to infer appropriate response plans for potentially impacted communities and relevant authorities. 4
Figure 1: Map of Greater Melbourne Area and land use. ABARES 2017
Flooding Management Definitions In motive of readers obtaining accurate understanding throughout this report, the following provides basic definitions of concepts concerning flooding management. Flood High water levels caused by excessive rainfall, storm surge or dram break that overtop the natural or artificial banks of a stream, creek, river, estuary, lake or dam (Middlemann, M. H., & Middelmann, M. (2007). Hazard Flood hazard is the extent of flooding determined by variables such as elevation, geology, rainfall, and flow accumulation (Sui, D. Z., & Maggio, R. C. 1999). Risk Chance of something happening that will have an impact on objectives.Risk is measured in terms of a combinations of the consequences of an event and their likelihood. Risk depends on three factors: hazard, exposure and vulnerability (Crichton, D. 1999). Vulnerability Degree of susceptibility and resilience of the community and environment to hazards (Middleman, M. H., & Middelmann, M. (2007) Tangible costs Cost as a result of the hazard event in which holds a market value. Referring to examples of damage to property, transport infrastructure, telecom infrastructure and vehicles. (Deloitte Access Economics, 2017). Intangible costs Direct and indirect damages that can not be easily be quantified. Referring to examples such as death, injury and impact of mental health wellbeing. Includes opportunity cost of the next best alternative use of the resource that is foregone (Deloitte Access Economics, 2017).
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Figure 2: Flash Flooding in South Melbourne December 2018 . (Herald Sun, 2018)
Figure 3: Flash Flooding on Punt Road and Swan Street, December 2018 . (Herald Sun, 2018)
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LITERATURE REVIEW The authors selected the region of Greater Melbourne as a case study example for flood risk analysis and flood risk management. For the purpose and context of flood risk analysis in this report, Geographic Information System (GIS) technology has been utilised as the principal tool of analysis. Methodologies applied through GIS environment such as Flood Hazard Index (FHI) and multi-criteria parameters for analysis (figure XX) were used to produce spatial visualisations for areas in Greater Melbourne that are from low to high risk (XX). The customary use of GIS for spatial risk analysis and hydrological risk analysis infers the reliability of using such software (Kazakis, N., Kougias, I., & Patsialis, T. 2015). Other hazard risk analysis case studies have utilised GIS integral to their methodology, such as Wittwer’s (2004) on modelling the economic impacts of a hypothetical earthquake in the Perth metropolitan region with the integration of building and vulnerability models and economic models.
Methodology Flood risk analysis using GIS environment was supported by literature of previous case studies in similar topics of research. As GIS is a database that provides systematic data storage, analytical tools and mathematical data elements (Kazakis, N., Kougias, I., & Patsialis, T. 2015). The availability to input parameters for specific measures are an essential element to ‘connect spatial analysis to real-world decision making’ (Kazakis, N., Kougias, I., & Patsialis, T. 2015). This helps communicate conclusive results of spatial information for management and decision making that could be used by responsible authorities of potentially impacted communities. The use of digital elevation data (DEM) as the primary data used in analysis of catchment typography (Moore, I. D., Grayson, R. B., & Ladson, A. R. (1991) is essential in achieving accurate digital representation of topography and spatial analysis. It is common practice in flood risk analysis to superimpose GIS layers of geological and hydrological information (Kazakis, N., Kougias, I., & Patsialis, T. 2015). GIS is convenient to produce raster DEM topographic representation; this is due to high-quality interpolation designed to handle a wide variety of input data types. From further findings in geomorphological literature, it was validated that this paper were to approach analysis of the catchment area in terms of topographic scale attributes, such as slope, hillshade, aspect and elevation (Wilson, J. P., & Gallant, J. C. (2000). However, the disadvantages of using such a model belies in the inaccuracy of representation as the size of the grid affects computational efficiency and it does not count the abrupt changes in elevation of catchment areas.
Figure 4: Example of workflow in decision making for Flooding Hazard Index and use of Geographic Information System criteria (Kazakis, N., Kougias, I., & Patsialis, T. 2015).
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The case studies of Nektarios N. Kourgialas & George P. Karatzas (2011) and Elkhrachy, I. (2015) were used as points of reference for hydrological mapping and multi-criteria risk analysis. These studies considered contributing factors toward flooding events such as spatial distribution, volume capacity and rainfall intensity. Elkhrachy, I. (2015) thoroughly integrated catchment conditions such as run off, soil type, drainage density, land use and distance of urban centres to main channels into GIS analysis. These causative factors were also used for impact weighting of flood causative factors to get a composite flood hazard index (FHI). Nektarios N. Kourgialas & George P. Karatzas (2011) applied the following variables that contribute to flooding risk and vulnerability: elevation, flow accumulation, rainfall intensity, slope, geology, and land use. As Melbourne terrain does not have much variation in altitude and is characterised by low lying coastline (especially the Melbourne CBD). Therefore, rainfall intensity data inputs was dismissed as being appropriate to incorporate into variable for input data analysis. Alternatively, 100 year ARI data was used and support by the methodology and findings by Habete, D., & Ferreira, C. M. (2017) who also proved other data inputs such as that water depth tables have been popularly used for modeling capacity of soils to store water instead of using rainfall intensity. From the reviewing of such papers and established research, it was apparent that multi-criteria analysis requires compiling data from different sources, formats and coordinate system. The parameters of flow accumulation, elevation, slope, geology, depth water table, land use and distance to rivers were used to produce flood hazard map. The weight definition and process of analysis was aided by reference to the flowchart as seen in Figure (XX). Hydrological mapping and risk analysis is essential to management planning and policy for emergency responses to flooding and other natural hazard events. By providing onset data and visualisation for areas, responsible authorities, urban water system operators and businesses will be provided with the tools necessary to enhance management. Keremane’s (2015) paper, in using Adelaide as the case study site, provides valuable commentary in adaptive risk management and the role of sustainable policy in ‘water-sensitive cities to response to climate change’ for the Australian context. This will prove to be more effective than traditional planning methods and support advocacy to move from large-scale centralised supply infrastructure towards a small scale and decentralised local scale. As Melbourne has a low-elevated terrain, other methods using Digital Terrain Model (DTM) in the GIS environment can be seen as viable for spatial analysis for the impacts of flooding. This would quantify flood water levels, velocity and flow. Another alternative use would be hydrological-hydraulic modelling to produce visual conceptualisation of disaster event trends. It is important to include in vulnerability of communities that would be impacted. This demands the overlay of demographic population and built environment overlay data, this would include vulnerable groups such as the elderly and youth in terms of demographic; and hospitals and schools in terms of high risk built environment land uses.
Flood Management Strategy The authors derived inspiration from international case study examples that could be appropriately applied to the context of Greater Melbourne. Nektarios N. Kourgialas & George P. Karatzas (2011) explore coastal flood management strategy in Greece where the karst regions have historically generated flash floods, much like in urban centres of Greater Melbourne in recent months. In this study the parameters applied in the hydrological-hydraulic modelling of the site forecasts events, from here emergency services will be apply to execute efficient emergency flood warning systems as a pre-flood strategy measure (FIGURE XX).
Figure 5: Flood warning system timeline Kourgialas, N. N., & Karatzas, G. P. (2011).
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With climate change changing our perception of the environment and the human relationship with the environment we impact, social desires and views are demanding appropriate responses to such imminent realities in our environment(Klijn, F., Kreibich, H., De Moel, H., & Penning-Rowsell, E. 2015).). Drawing from sustainable and resilient flooding management examples in the Netherlands in Rotterdam, Australia could learn the criteria in which are necessary to fulfill to mitigate damage, life and economic loss in the event of a flooding disaster. Adaptive management planning co-depends on policy analysis and spatial analysis. However, it is important to recognise that Melbourne, unlike the Netherlands, does not hold a delta system in which means that 55% of the country’s surface is flood-prone (Klijn, F., Kreibich, H., De Moel, H., & Penning-Rowsell, E. 2015).). This is not the case for Melbourne but the measures taken in the Netherlands to apply comprehensive flood risk management schemes are valuable to understand, critique and take inspiration from. As vulnerability of flood-prone areas worldwide increases, so does the risk exposure increase to communities and economic development. The Delta Sub-Programme in the Netherlands addresses this predicament through policy measures addressing load reduction, flood protection, exposure reduction, vulnerability reduction as a four part approach toward a flood risk management (Klijn, F., Kreibich, H., De Moel, H., & Penning-Rowsell, E. 2015).. This could be used at a local state and council authority scale in Victoria in response plans to delegate responsibility over different scales of risk reduction schemes
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METHODOLOGY
A five step approach to derive the results 1. Defined the problem and study area 2. Prepared criteria, datasets, variables and evaluation scales - underpinned by research and literature review 3. Pre-processed data 4. Weighted the values based on our research, uniformly reclassified all data sets and overlayed for combined view 5. Evaluated the results
1 Defined the problem and the study area The study are of Greater Melbourne was selected to analyse and visualise flooding risks based on the prediction that sea levels will rise as a result of global warming (Coastal Risk, 2019). The priority for climate change adaptation measures has changed since the recent flash flooding experienced in Greater Melbourne in December 2018 (Figures 2 and 3), and a proposal that further preparedness is required to manage further incidences. This will be informed by geospatial analysis to determine areas of highest risk and vulnerability.
Figure 6: Map of Melbourne’s predicted coastal risk based on climate change modelling (Coastal Risk, 2019)
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2 Prepared criteria, datasets, variables and evaluation scales - underpinned by research and literature review Multi-criteria analysis requires a concerted effort to ensure that the criteria set will provide results that focus the right action. A literature review was undertaken to understand current thinking of flood management, the indicators and contributors of risk to population and infrastructure, and the methods applied to model those risks. Data sets were researched and selected to answer each of these variables, to appropriately illustrate hazards and risks. Causative factors of flooding were first identified for most compelling analysis. Through research of flood management and disaster management, variables were selected for their water-holding and infiltration characteristics - as a general rule, flooding risk is increased where the water table is intercepted, and velocity of water is increased (Elkhrachy, 2015) To summarise the variables and their properties: Land use highlights the interaction of natural landscape and the gradient of human modifications to that landscape. Man-made structures and urbanised areas are characterised by impervious surfaces, compromising infiltration capacity (Nektarios et al, 2011). Geology was used to infer water-holding potential of the area based on porosity percentage. As a general rule, runoff from intense rainfall or rise in water table is likely to be more rapid with less porous rock, which has low permeability and a reduced carriage to groundwater. Classifications have thus been applied based on this attribute, with the higher percentage porosity assigned the lowest risk (Earle, 2015) Slope and elevation is an effective gauge of flood risk, where high slope and low elevation combine to create a high risk, where water pools (Wilson et al, 2000)
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3 Pre-processed data
Multi-criteria analysis requires compiling data from different sources, which may have different extents, formats and coordinate systems. To align these, pre-processing and data transformation was applied to meet the criteria for our analysis. This included: ● ● ● ● ●
Vector geoprocessing tools - including clipping and buffering Selecting data by location and attributes to create new features Reprojecting data to align coordinate systems to GDA94-VICGRID94 for Melbourne Converting vector data to raster surfaces Raster analysis performed with hydrology tools and Euclidean distance
Figure 7: Methodology Workflows
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4 Weighted the values based on our research, uniformly reclassified all data sets and overlayed for a combined view Distilling multi-criteria data sets to a combined view requires that data is reclassified. A 1-5 rating scale was selected to be applied across all maps to illustrate areas of least risk and greatest risk. Criteria was set with the following variables and weightings, informed by literature that indicates that infiltration potential is a key criticality indicator for flood risk. Vulnerabilities were targeted for their human impact. Classification of hazards Rating
Slope, elevation
Flow accumulation
Geology
Land use
Waterways
Lowest slope, highest elevation
Lowest accumulation potential
Marine sedimentary (highest infiltration)
Forest (highest infiltration)
Greatest distance from waterways
2
Sedimentary
Green space
3
Metamorphic
Pasture areas
4
Igneous extrusive
Periurban areas
Igneous intrusive (lowest infiltration)
Urban areas (lowest infiltration)
1
5
High slope, low elevation
Highest accumulation potential
Smallest distance from waterways
A weighted overlay analysis was performed over all data sets. Now reclassified, these raster surfaces have simpatico that allows all to be overlayed to identify the composite risks and vulnerabilities of all layers. Inputs were all reclassified rasters with weightings specified for each variable. The percentage of influence was applied using spatial analyst weighted overlay tool. This extracted areas of highest risk to illustrate key criteria for discussion and recommendation. Weightings for risk and vulnerability variables Risk Variable
Elevation
Slope
Depth to water table
Flow Accumulation
Land use
Geology
Distance to waterways
Weighting
27.5
19
7.5
7.5
15
20
12.5
Vulnerability Variable
Population density
Main roads underwater
Distance from hospital
Weighting
50
15
35
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5 Evaluated the results
Results were evaluated by attributing a rating scale of 1-5 to visualise areas of greatest risk and vulnerability with all layers combined in the overlay analysis. Desktop analysis was performed using exported attribute tables to locate the top ten and bottom ten areas at risk for disaster management, and lowest risk for evacuation management. The results tend to reflect the impacts observed in the December 2018 flash flood (Figure 2), which were concentrated in inner Northern centres (Herald Sun, 2018). While the results are fit-for-purpose to target areas for immediate and longer term investment and planning, acknowledged limitations of the study include: ●
Data inadequacies - flood hazard assessment is based on data of differing time scales. The overlay is temporally compromised. A finer grade of analysis would be determined by sample data sets of these variables, overlayed to the current data sets with a higher weighting.
●
Rainfall history and climate data has not been used due to the limited variation of these results anticipated across such a small study area, and the focus on sea level rise. However, rainfall can be compelling to offer more precise modelling on surface runoff impacts, combined with the threat of rising waters.
●
Weightings for the overlay analysis and raster calculations have been based on interpretation of literature and should be read as indicative only, as with all data models. More precise modelling may be applied with regression analysis
●
Resolution of rasters were uniformly applied at size 50. Higher resolution would more finely tune the result.
●
Hydrology calculations depend upon precision of the topographic maps and DEM data. Difference in scale of maps can simplify the results, thus an investment in higher quality datasets may offer greater precision, albeit a cost-benefit analysis would drive the decision, to right-size the precision required for such an outcome.
●
Economic impacts can be sized by categorising and weighting critical infrastructure, delivering finer granularity for cost-benefit planning
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FLOODING HAZARD AND RISK ANALYSIS MAPS
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RESULTS
Figure 8:
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RESULTS
Figure 9:
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RESULTS
Figure 10:
Top 10 vulnerable SA2 regions ( highest risk to lowest) Richmond Dandenong North Southbank Yarra Valley Wyndham Vale Werribee - West Abbotsford South Melbourne South Yarra - East South Yarra - West
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RESULTS
Figure 10:
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RESULTS
Figure 11:
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RESULTS Figure 12:
Top 10 SA2 regions at risk ( highest risk to lowest) Richmond, City of Yarra Werribee West, City of Wyndham Wyndham Vale, City of Wyndham Dandenong North, City of Dandenong Fitzroy North, City of Yarra Abbotsford, City of Yarra South Melbourne, City of Port Phillip Southbank, City of Melbourne Alphington - FairďŹ eld, City of Darebin Brunswick East, City of
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RESULTS
Figure 13:
Top 5 hospitals at risk ( highest risk to lowest) The Melbourne Clinic Private, Richmond The Women’s Day Clinic, Richmond Specialist Centre, Docklands Hawthorn Birth and Development Centre, Hawthorn Victorian Rehabilitation Centre, North Melbourne
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RESULTS
Figure 14:
Top 5 schools at risk ( highest risk to lowest) Little River Primary School, Little River Victorian College of the Arts, Southbank Lynall Hall Community School, Preston Richmond Primary School, Richmond Yarra Primary School, Richmond
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RESULTS
Figure 15:
Top 5 retirement homes at risk ( highest risk to lowest) St Vincent’s Hospital, Richmond Mercy Health & Aged Care, Richmond AAA Nextt, Richmond Blue Cross Community Care, Kew Melbourne Health, Brunswick
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DISCUSSION Variable flood hazards have been combined to visualise areas of greatest risk. These variables in situ in Figure 8 are classified on the 1-5 rating scale discussed earlier, clearly indicating risk is concentrated in coastal and southern areas, with the risk retracting toward the outer perimeter of greater Melbourne. The hazards underlying these areas of risk are mapped in Figure 9, and are most prominently attributed to three key classes in this local context: ●
Land use: the urban-rural gradient indicates reductive impervious surfacing from inner-city to peri-urban areas, generally trending south to north
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Geology: stark delineation of rock attributes from lowest percentage porosity to highest from east to west, a feature of Melbourne’s volcanic sand-belt legacy
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Elevation: the very flat landscape of inner Melbourne and coastal areas is contrasted against the higher elevations in the north, illustrating the low topography of the urban areas.
While these results are expected individually, when overlayed they offer powerful visualisations of these concentrated hazards. Vulnerabilities to infrastructure and human population have been illustrated in Figure 10, targeted for their criticality for population movement. A key contrasting attribute is population density, which is almost entirely confined to inner Melbourne. Of note across all figures, Richmond SA2, part of City of Yarra is referenced, including vulnerable infrastructure (train stations) and populations (aged care, hospitals, schools). Vulnerabilities and hazards are combined to narrow our focus to regions at greatest risk, shown in Figure 12. Based on this, key focus areas for flood planning and evacuation management suggest The Cities of Yarra and Wyndham, each with two SA2 regions in the top 5 highest risk. Across all figures, Richmond SA2, part of City of Yarra is referenced, including vulnerable infrastructure (train stations) and populations (aged care, hospitals, schools). Richmond includes arterial roads, and multiple public transport routes including trams and trains, including a main interchange at Richmond Station. At risk is industry - including large manufacturing factories and three of the 82 activity centres in the Melbourne 2030 strategy, and a world-class sporting precinct to name some of the key longevity streams (Wikipedia, 2019). Based on 2016 Census Data, The City of Yarra has a population three times higher than City of Wyndham (Australian Bureau of Statistics, 2016). Coupled with its rich source of industry, Richmond must have the funding and resources to respond effectively to the recommendations, with funding strategies that can deliver climate change adaptation, as well as response planning. Vulnerable population - schools (children), hospital (sick), retirement villages (elderly) are illustrated in figures 13-15. Converse to the highest risk areas, hospitals and schools with lowest risk should be targeted for evacuation planning. Of the lowest risk potential crisis points, the closest for both the City of Yarra and the City of Wyndham are Mercy Public Hospital and Epping Secondary College - centres that should be included in disaster management planning. Potential crisis centres - hospitals and schools at lowest risk
Lowest risk hospitals
Lowest risk schools
The Northern Hospital
St Thomas More’s School
Mercy Public Hospital
Ferny Creek Primary School
The Bays Hospital
Epping Secondary College
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RECOMMENDATIONS Based on the findings of flood risk analysis, the following recommendations are presented as a viable guideline concerning flooding disaster management. A comprehensive framework of emergency response (Cova, T. J. 1999), has been referred to with the incorporation of GIS analysis tools for disaster mitigation, preparedness and response. An account of existing and accountable authorities have been identified with roles to ensure the mitigation in regions at high risk of flooding:
Department of Environment, Water, Land and Planning
Provide access to flood prediction technology, support strategy implementation
Victorian State Emergency Services (VICSES) VIC Roads
Manage Road Closure
Catchment Management Authorities
Develop floodplain management, maintenance of levees, access to flooding intelligence technology
Country Fire Authority
Support crisis management, Support shelter facility and communities
Melbourne Water
Work with VICSES and Local Councils to establish municipal response strategies
Bureau of Meteorology (BoM)
Support VICSES, flood prediction agency
Ambulance Victoria
Response to emergency calls, support relocation of health and age care facilities
Australian Red Cross
Support Victorian Police and Ambulance Victoria
Local Municipal Councils
Support strategy plans and liaise with VICSES, other emergency services and assist in river levees and gauge maintenance
It is recommended that analysis and review of management plans are to be frequented every three years to ensure relevant arrangements and viable solution. The following is a developed subdivision of advisory responses has been developed for the Victorian State Government; This entails matters on population movement, industry response, environmental impact statements and infrastructure management in the Greater Melbourne area.
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1. Population Movement To direct population away from areas of high risk, train stations, tram lines, bus routes and main roads will be blocked or cancelled in service. This will be done in order to ensure people are deterred from flooding risk. It is the duty of VICSES to communicate emergency warnings and recommendations to Public Transport Victoria and VicRoads to block transport services and access in coordination with Victorian Police in affected municipalities. It is the duty of VICSES, Bureau of Meteorology (BoM)and Melbourne Water to communicate emergency warnings via telecommunications. Flood forecasting, prediction agency and emergency information are to be updated with issues of official forecasts by VICSES and BoM. From findings of analysis the following stations have been flagged as high risk and should be immediately prioritised in blocking access and services: I. East Richmond (Alamein, Belgrave, Glen Waverley and Lilydale lines) II. Burnley (Alamein, Belgrave, Glen Waverley, and Lilydale lines) III. Kensington (Craigieburn line) IV. Heyington (Glen Waverley line) V. Middle Footscray (Sunbury) Trams lines connected to train station lines are also to be disrupted from service in areas of high risk as deemed by VICSES. Hospitals and Schools at low risk are to be incorporated as locations for emergency shelter and additional health aid and services to be provided for. This include lowest risk hospitals and schools with appropriate capacity of emergency services are: I. II. III. IV. V. VI.
The Northern Hospital (Epping Mercy Public Hospital (Heidelberg) The Bays Hospital (Mornington) St Thomas More’s School (Hadfield) Ferny Creek Primary School (Ferny Creek) Epping Secondary College (Epping)
2. Industry Response It is recommended to the State Government to initiate a program to create a flood emergency warning committee. This is recommended to be piloted in the region of Greater Melbourne due to findings of high levels of risk due to rising sea-levels and historic events of flash flooding. As BoM is a leading organisation for flood forecasting and warning services, it is essential for their participation. The committee suggested are: I. Department of Environment, Land, Water and Planning II. Bureau of Meteorology (Chair/Secretariat) III. Victorian Rural Water Authorities IV. Victoria State Emergency Service, V. Local Government VI. Melbourne Water VII. Other State Government agencies (as required). The purpose of the committee is to establish a Warning System Procedure that will be used across in a standardised fashion across municipalities. The committee will coordinate the implementation of flood warning systems in accordance with appropriate standards; promote communication of flood warning information to the affected communities; monitor and review the performance of flood forecasting and warning services. For Urban water businesses, planning tools are to be provided by state government to focus on adaptive climate change policy, this is to be done to address the uncertainty of hazard whilst maintaining water security for populations. AdaptWater is a recommended online risk and cost-benefit analysis tool to quantify and project probability of damage and failure of assets from existing and potential hazards. Local Government Council at high risk such as Port Phillip, Westernport, Yarra, Greater Dandenong and Wyndham, are recommended to revise and contact VICSES for comprehensive emergency response updates. 27
3. Infrastructure Management Levee Management and Flood intelligence technology for decision making and defence are recommended as the first points of measures taken for flooding mitigation. Levee management is crucial for the protection of property, public and private infrastructural assets. 98% of Victoria’s rural levees are not formally maintained (Emergency Management Victoria, n.d.), this means that the protections against moderate to minor floods are not ensured. A more stringent routine of maintenance, structural upgrade and management needs to be implemented by Catchment Management Authorities, DELWP and Local Councils. Urban levees need to be established along waterways and coastal areas in Port Phillip, Westernport, Yarra, Greater Dandenong and Wyndham. Although levees do not ensure complete safety from inundation, they create opportunity for the safe evacuation of population. Flood intelligence technology allows for accurate information relating to actions to be taken in response to identified hazard consequences. VICSES is recommended to work with DELWP in ensuring that local councils are provided with sufficient flood information. The flood intelligence platform ‘FloodZoom’ ought to be advised to responsible authorities. State Victorian Government is recommended to establish three tier management teams to assist and support councils in the communication and development of comprehensive risk plans. These teams should be [1] State [2] Regional [3] Crisis Teams with delegated responsibilities and control centres for community resources and resupply arrangements. 4. Environmental Impact Statement A Rapid Impact Assessment Matrix (RIAM) be developed by State Victorian Government and DELWP to implement structural flood mitigation measures in areas of high level risk (City of Port Phillip, Wyndham, Wavenport, Dandenong, Melbourne, Werribee, Yarra). The principal of the RIAM is to provide decision makers and responsible authorities viable sources of information to incorporate into planning processes and infrastructure projects. According the statutory requirements of the Local Government Act 1989, Melbourne Water Corporation Act 1992, Planning and Environment Act 1989; Advanced environmental impact interpretation based on the outputs of hydraulic, hydrological, sediment, water quality and ecological modelling studies is required. Detailed studies provided by DELWP including flora, fauna, cultural heritage, hydrology, landscaping, design and visual impact analysis, geotechnical and marine based investigations and social impact research, are to be referred to and assessed for each council area.
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CONCLUSION Adapting to climate change to manage flood risk is a new reality for urban planners and civic managers. In order to inform funding priorities to ensure the right LGAs have resource to respond effectively, this report is to identify flood prone areas within the Greater Melbourne region, and the risks and vulnerabilities.
The study has been conducted using geospatial analysis and underpinned by contemporary research and their application to selection of variables and their weightings to deliver a visualisation, delivering a key artefact for disaster management planning. For deeper analysis, our recommendations extend to the following subsequent actions, acknowledging the limitations of the study: ●
●
●
● ●
●
Data inadequacies - flood hazard assessment is based on data of differing time scales. The overlay is temporally compromised. A finer grade of analysis would be determined by sample data sets of these variables, overlayed to the current data sets with a higher weighting. Rainfall history and climate data has not been used due to the limited variation of these results anticipated across such a small study area, and the focus on sea level rise. However, rainfall can be compelling to offer more precise modelling on surface runoff impacts, combined with the threat of rising waters. Weightings for the overlay analysis and raster calculations have been based on interpretation of literature and should be read as indicative only, as with all data models. More precise modelling may be applied with regression analysis Resolution of rasters were uniformly applied at size 50. Higher resolution would more finely tune the result. Hydrology calculations depend upon precision of the topographic maps and DEM data. Difference in scale of maps can simplify the results, thus an investment in higher quality datasets may offer greater precision, albeit a cost-benefit analysis would drive the decision, to right-size the precision required for such an outcome. Economic impacts can be sized by categorising and weighting critical infrastructure, delivering finer granularity for cost-benefit planning
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FIGURE REFERENCES Cover Page Image Source: Herald Sun, December 2018. Retrieved from: https://www.heraldsun.com.au/news/victoria/months-worth -of-rainfall-set-to-smash-melbourne/news-story/cde03418e 265e121ef26aabb3f942f6d
[Figure 13]Risk value of hospitals in Greater Melbourne. P. Ginnivan, 2019
[Figure 1] Catchment Areas and Land Use status, Catchment scale land use of Australia, Department of Agriculture and Water Resources, ABARES , 2017 )
[Figure 15]Risk value of retirement homes in Greater Melbourne. P. Ginnivan, 2019
[Figure 14] Risk value of schools in Greater Melbourne. P. Ginnivan, 2019
[Figure 2] Melbourne and surrounding suburbs cop a soaking in peak-hour downpour, December 2018, Herald Sun. Retrieved from: https://www.heraldsun.com.au/news/victoria/melbourne-an d-surrounding-suburbs-cops-a-soaking-in-peakhour-downpo ur/news-story/dd3f259ff594dfc3bec9320a94536f46 [Figure 3] Melbourne and surrounding suburbs cop a soaking in peak-hour downpour, December 2018, Herald Sun. Retrieved from: https://www.heraldsun.com.au/news/victoria/melbourne-an d-surrounding-suburbs-cops-a-soaking-in-peakhour-downpo ur/news-story/dd3f259ff594dfc3bec9320a94536f46 [Figure 6] Map of Melbourne’s predicted coastal risk, based on climate change modelling (Coastal Risk, 2019) Figure 7: Methodology Workflows [Figure 8] Greater melbourne flood hazard map. P. Ginnivan, 2019 [Figure 9] Greater melbourne flood hazard map. P. Ginnivan, 2019 [Figure 10] Greater melbourne vulnerability maps. P. Ginnivan, 2019 [Figure 11] Greater Melbourne Flood Risk Map. P. Ginnivan, 2019 [Figure 12] Greater Melbourne Flood Risk Map by SA2 Region. P. Ginnivan, 2019 30
Keremane, G. (2015). Role of Sustainability Policy Entrepreneurs in Building Water-Sensitive Cities to Respond to Climate Change: A Case Study in Adelaide, Australia. In Managing Water Resources under Climate Uncertainty (pp. 359-375). Springer, Cham.
BIBLIOGRAPHY Australian Bureau of Statistics (2016). Australian Census. Retrieved from: /www.abs.gov.au/websitedbs/D3310114.nsf/Home/Census Deloitte Access Economic, (2017, Novermber) Building resilience to natural disasters in our states and territories. Retrieved from:
https://www2.deloitte.com/au/en/pages/economics/articles/buil ding-australias-natural-disaster-resilience.html
Klijn, F., Kreibich, H., De Moel, H., & Penning-Rowsell, E. (2015). Adaptive flood risk management planning based on a comprehensive flood risk conceptualisation. Mitigation and Adaptation Strategies for Global Change, 20(6), 845-864. Kourgialas, N. N., & Karatzas, G. P. (2011). Flood management and a GIS modelling method to assess flood-hazard areas—a case study. Hydrological Sciences Journal–Journal des Sciences Hydrologiques, 56(2), 212-225. Ladds, M., Keating, A., Handmer, J., & Magee, L. (2017). How much do disasters cost? A comparison of disaster cost estimates in Australia. International journal of disaster risk reduction, 21, 419-429. Lichter, M., & Felsenstein, D. (2012). Assessing the costs of sea-level rise and extreme flooding at the local level: a GIS-based approach. Ocean & coastal management, 59, 47-62. Melbourne Water (2015), Flood Management Strategy
Climatexchange Scotland (2016). Narrative flooding and infrastructure. Retrieved from: https://www.climatexchange.org.uk/media/2348/narrative_flooding_an d_infrastructure.pdf (29/5/2019)
Moore, I. D., Grayson, R. B., & Ladson, A. R. (1991). Digital terrain modelling: a review of hydrological, geomorphological, and biological applications. Hydrological processes, 5(1), 3-30.
Cova, T. J. (1999). GIS in emergency management. Geographical information systems, 2, 845-858.
Middlemann, M. H., & Middelmann, M. (2007). Natural hazards in Australia: identifying risk analysis requirements. Geoscience Australia.
Dufty, N. (2012, April). Learning for disaster resilience. In Proceedings of the Australian & New Zealand Disaster and Emergency Management Conference held in Brisbane, Queensland, Australia (pp. 150-164). DELWP. (2016). State of Victoria Department of Environment, Land, Water and Planning, Victorian Floodplain Management Strategy Section 1. Retrieved from: https://www.water.vic.gov.au/managing-floodplains/new-victorian-floo dplain-management-strategy (accessed 29/05/2019 2:08pm) Earle, S. (2015). Physical Geology. Victoria, B.C.: BCcampus. Retrieved from https://opentextbc.ca/geology/. Elkhrachy, I. (2015). Flash flood hazard mapping using satellite images and GIS tools: a case study of Najran City, Kingdom of Saudi Arabia (KSA). The Egyptian Journal of Remote Sensing and Space Science, 18(2), 261-278. Habete, D., & Ferreira, C. M. (2017). Potential Impacts of Sea-Level Rise and Land-Use Change on Special Flood Hazard Areas and Associated Risks. Natural Hazards Review, 18(4), 04017017. Handmer, J., Ladds, M., & Magee, L. (2018). Updating the costs of disasters in Australia. Australian Journal of Emergency Management, The, 33(2), 40.\ Kazakis, N., Kougias, I., & Patsialis, T. (2015). Assessment of flood hazard areas at a regional scale using an index-based approach and Analytical Hierarchy Process: Application in Rhodope–Evros region, Greece. Science of the Total Environment, 538, 555-563.
Schumann, A. H., Funke, R., & Schultz, G. A. (2000). Application of a geographic information system for conceptual rainfall–runoff modeling. Journal of Hydrology, 240(1-2), 45-61. Snoussi, M., Ouchani, T., & Niazi, S. (2008). Vulnerability assessment of the impact of sea-level rise and flooding on the Moroccan coast: the case of the Mediterranean eastern zone. Estuarine, Coastal and Shelf Science, 77(2), 206-213. Sui, D. Z., & Maggio, R. C. (1999). Integrating GIS with hydrological modeling: practices, problems, and prospects. Computers, environment and urban systems, 23(1), 33-51. TSENG, C. P., & PENNING‐ROWSELL, E. C. (2012). Micro‐political and related barriers to stakeholder engagement in flood risk management. The Geographical Journal, 178(3), 253-269. Vinh Hung, H., Shaw, R., & Kobayashi, M. (2007). Flood risk management for the RUA of Hanoi: Importance of community perception of catastrophic flood risk in disaster risk planning. Disaster Prevention and Management: An International Journal, 16(2), 245-258. Wikipedia (2019). Richmond, Victoria. Retrieved 6 June, 2019 from https://en.wikipedia.org/wiki/Richmond,_Victoria Wilson, J. P., & Gallant, J. C. (2000). Digital terrain analysis. Terrain analysis: principles and applications, 6(12), 1-27
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APPENDIX A - WORKFLOW CHARTS
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APPENDIX B: INDIVIDUAL REFLECTION Patrick Ginnivan My contributions to this project consisted of: ● ● ● ● ● ● ● ●
Exploration of ideas and concepts and related theory Collection of data Determining input factors Analysis and interrogation of data Extrusion of key attributes from data ArcGis work Creation of maps Workflow charts
Having worked together in the previous assignment and having developed our own strengths, it allowed the group to focus on these. For me this consisted of the mapping and ArcGIS work. I believe it may have been even more beneficial to be more involved in the initial research of the task, allowing for possibly greater concepts and relationships to be explored in the data. However the team did a great job of conveying all ideas. One of the more interesting and seamless projects i’ve done, it allowed the concepts to be explored to a self desired depth. And the practical implementation of the theoretical concepts explored in lectures was a great way to learn.
Shauna Morris One of the most positive group work experiences I have had made this complex task easier to deliver. The collaboration was key to focus on our intended outcome. More importantly, having had the experience of the first assessment, we were more aware of our strengths and how to apply them for best outcome. My individual contributions to the final submission included: ● ● ● ● ● ●
Coordinating inputs and deliverables, documenting to support accountability nd time management Development of the key messages and metrics in consultation with the team Research to inform reclassification and hazard and vulnerability variables. Data and collection and transformation Support to distil the outputs from the map/datas to target key discussion points Ownership of the methodology, discussion and conclusion sections of the final product, coordinating inputs required and peer review from my colleagues.
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Gabrielle Head-Gray My contributions to this assignment were: -
Discussion and development of the key messages and metrics in consultation with the team Professional Layout and outline of delegated work Literature Review, Introduction, Abstract, Key deďŹ nitions and aid with parameters and knowledge of methodology, Recommendations for response plan Being a communicative and active team member, with coordination and ďŹ nalising of submission.
Having worked in our previous project together, my teammates and I were secure in knowledge of strengths to produce thorough work output in an efďŹ cient manner. With more initial stage research and time and less pressure on results, the division of ArcGIS and literature methodology would have produced greater in depth knowledge on hazard risk mapping. This being said, I believe our team executed tasks and have produced a report highly satisfactory with the time frame at hand. It was also a positive learning environment to be in which made it all the more easier. The more prominent takings were methodology in using hydrology tools that before this project I had little knowledge in. It was greatly interesting in researching the recommendation options that were viable in the Greater Melbourne Region.
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