Urban Beat Issue 2 - December 2016
Selected stories from the second issue of Urban Beat, the newsletter of the Clean Air and Urban Landscapes Hub, can be read online below. A pdf copy of the full issue can be downloaded here.
How to Grow a Research Community
Professor Peter Rayner, University of Melbourne
Hub Leader, Clean Air and Urban Landscapes Hub
One of the most important outcomes for CAUL is not, to my knowledge, written anywhere: To build a sustainable urban research community in Australia. The need for this is clear enough, the problems are so complex that only a collection of minds working together can address them. Unintended consequences are usually the result of not asking the person who knew about them, rather than a complete knowledge gap.
The easiest way to build a research community is to fund it. Good researchers will respond to targeted funding effectively if not always enthusiastically. The flip-side is that enthusiasm evaporates with the funding.
A more robust approach is that researchers come to identify intellectual opportunities in the new community. In this version the funding primarily establishes the community for long enough that it becomes self-sustaining. The six-year life of CAUL gives us a real chance to do this.
How will we know if we have succeeded? My success criterion will be the number of projects beyond CAUL which spin up from internal discussions. These co-occur outside CAUL funding or continue beyond its life.
A year into the active research phase of CAUL we can start to assess progress. We have, for the first time in Australia, connected state-of-the-art modelling of local traffic flow with detailed measurement and modelling of air pollution. Although this output wasn’t originally envisaged in CAUL’s urban systems research it certainly will be an important tool for key stakeholders interested in densification around traffic corridors.I look forward to more successes like this.
Agent-based Modelling in Environmental and Social Science
Scientists love a good model. In recent decades a new form of modelling has emerged – Agent Based Modelling. This technique is being used by CAUL Hub scientists studying traffic behaviour, but has much wider applications.
Modelling is crucial to scientific research. It presents a simplified version of a real system that allows scientists to understand these systems without having to attempt the impossible task of observing every detail.
Traditionally, modelling has been from a centralized perspective. That is, it has involved working out some equations that describe the overall behaviour of a system. Sometimes these equations can be solved precisely, but more often modelling involves using a computer to see how they play out over time.
Agent Based Modelling (ABM) comes from a different angle – it takes a decentralized view. Instead of seeking a set of governing equations, ABM considers a system as a collection of individual agents. Each agent has a set of rules that describes how they interact with each other. The model then allows each agent to follow its own rules.
Traditional modelling is useful in systems which may have lots of different parts but the interactions between those parts are easy to describe. Examples for this might be a collection of stars in a galaxy, interacting via the gravitational force, or a weather system. ABM, on the other hand, is useful for systems where the interactions are much more complex, such as social and ecological systems. It is particularly good at discovering emergent behaviours of the system—patterns that aren’t obvious from the properties of the individual, but which appear when those individuals start interacting.
One area where ABM is being used is within the Clean Air for Western Sydney and Beyond research project of the CAUL Hub. Transport emissions are the single biggest source of air pollution for the people who live and work in our cities, and so understanding how they are created is an important question. However these emissions depend on the choices that people make about driving, and this is a very complex problem.
Agent based modelling of traffic flows and travel times on the Sydney road network is being used by CAUL Hub researcher Hugh Forehead from the SMART Facility at the University of Wollongong, based on work by his SMART colleague Johan Barthelemy. Previous models of traffic have considered overall properties based on a few times of day – peak hour, daytime and overnight.
Using an ABM approach, much more detailed emissions profiles can be worked out. The traffic model developed by Johan relies on the simulated drivers’ (agents) ability to make decisions about which route to take depending on the perceived traffic conditions, resulting in more realistic simulated traffic flow.
Nam Huynh, also at SMART, has worked on transportation-based ABM previously. A model Nam developed for Transport NSW simulated an entire population in the Randwick and Green Square region of Sydney. The model allows for a simulation of how the population changes over time. This includes a simulation of aging, and of age-dependent life events (e.g. birth, death, and coupling). These life-events influence not only individuals but also entire households, affecting their transport and housing needs.
A significant part of ABM work is working out what properties need to be assigned to the agents in the model, such as the probabilities of individuals forming a household together in Nam’s Green Square population. Sometimes these properties can be assigned by looking at other empirical research in the area. Sometimes they need to be developed based on prior understanding of how the overall system operates.
As with all scientific techniques, ABM needs to be applied carefully. Nam points out that it has both benefits and challenges. “It’s good for scientific research—you can get very detailed results at low levels. But this is a danger—you can’t get the empirical information at this scale and so the model can’t ever be fully validated.”
Instead, ABM relies on doing a large number of simulations—an ensemble—and observing the patterns of behaviour seen in the system consistently over the ensemble.
These decisions about how to use ABM depend crucially on what the model is being used for. Simulations can be used for a range of different purposes in scientific research. Brian Heath, who completed a PhD on ABM in 2010, describes simulations as being Generators, Mediators or Calculators. Where knowledge about a system is high, a simulation can be used to make a specific prediction, like a weather forecast. ABM techniques are generally not well suited to this role, but they can be used in the other two cases. An ABM approach is often used to produce hypotheses about the system where the knowledge of that system is low.
ABM also works well in the middle range, where knowledge about a system is moderate, but the models still need refinement. In this case, an agent-based model can be used to explore the range of possible behaviours of a system, such as in the traffic model.
Leon Sterling, author of The Art of Agent-Oriented Modelling, reinforces this idea: “If I’ve got a model of a complex system, agent-based modelling allows me to test it. Computing power allows you to tinker and refine.” The techniques of ABM have been developed since mid 1980s, but have only really been fully applied in the last two decades. This is because simulating thousands – or millions – of agents at a time is computationally difficult, and so good ABM has only been possible since computers have become cheap and powerful enough.
However there are many more applications for ABM waiting to be developed. Hugh Forehead has had experience working with ABM for a decade. His previous applications of ABM have included simulations of processes in marine biology and in microbial communities. He highlights ecological modelling as an area where ABM has only just started to show its potential. “I would say that Agent Based Modelling is now well recognised within the scientific community, but there is still a lot of room for growth.”
Living Cities Alliance
Collaboration between the urban landscape architect community and ecologists and other research disciplines will be essential for designing the cities of the future. This idea was succinctly expressed by CAUL Hub researcher, Professor Richard Hobbs, at the International Festival of Landscape Architecture held in Canberra October 2016 and the Australian Institute of Landscape Architects (AILA) could not agree more.
One expression of this collaborative approach is the Living Cities Alliance, which began through a Workshop held at Parliament House, Canberra in February 2016. This forum, cohosted by AILA and Engineers Australia, and attended by CAUL Hub, was an opportunity to bring together interests from all parts of the green infrastructure spectrum – architecture, landscaping, water management, engineering, science, research, land management, policy, real estate and governance.
The Living Cities event helped to articulate a national Five Point Living Infrastructure Plan:
- National Living Cities Fund.
- Living Infrastructure as an Asset Class.
- Local Government Green Infrastructure package.
- National Green Streets and ‘Grey to Green’ Pilot Program.
- Minimum SITES Ratings for federally funded projects.
This five point plan is the beginning of an ongoing dialogue that seeks to establish resilient urban landscapes be it boulevards down arterial roads or stormwater harvesting that supports greener, cooler parks. Elevating the importance of urban landscapes within the management of cities requires a partnership approach across disciplines. AILA looks to partnerships with CAUL and other research groups to allow ecologists, green infrastructure experts and urban system researchers to connect with practitioners and managers to enable the Living Cities plan to be a reality.
One such partnership making this plan happen is Greening The West (GTW) in Melbourne where local governments, state agencies, infrastructure owners, researchers and services providers have been working together since 2011 to further the greening of western suburbs. GTW partnerships have obtained funding from federal and state governments and the private sector to deliver significant green infrastructure projects while discussions have begun with power companies to explore how the west can create a 21st century urban landscape ecology that sustains liveability and mitigates heat. These collaborations are able to develop good practice, such as the research work being undertaken by the CAUL Hub to understand the social and ecological benefits of the GTW project at Upper Stony Creek.
The skills and resources of many partners will be required to establish an urban ecological framework that ensures the ongoing liveability of cities into the climate change century. AILA and partners within the Living Cities Alliance are committed to collaboration to get us there.
Research Project Update: A National Framework for Urban Greening
A major focus of the CAUL Hub is to promote accelerated urban greening in order to improve the liveability of metropolitan environments. A critical dimension of this is analysing the existing extent and quality of vegetation cover, threats to this cover, and opportunities to increase urban greening. The CAUL Hub is collaborating with CSIRO and 202020 Vision to establish methods for analysing urban vegetation cover and to develop a framework for implementing this analysis on a nation-wide basis, to inform localised greening strategies.
The project is divided into four phases, of which the first is now complete. This has focussed on developing feasible procedures for evaluating green spaces in cities, and is ready to be implemented on a national scale. As a part of the City Deals initiative, the objective is to offer benchmarks and targets for consistent monitoring of urban canopies. Key priorities in designing the methodology have been viability, usability, scalability, and capacity for long-term monitoring. In the next phases of the project, the collaboration proposes to set up platforms accessible to the public, before finally working with state and local government partners to develop comprehensive greening strategies for Australian cities.
The method developed in the project’s first phase is focussed on the integration of height-stratified green cover maps with an assortment of urban land-use types, to identify the relationships between a city’s form, liveability and urban canopy. To maximise the effectiveness of the analysis as a decision-making tool, spatial data including socio-demographics, transport networks and heat island factor have been incorporated. A case study of Metropolitan Perth has been undertaken to trial the method and inform stakeholder engagement.
Aerial 3-D photography has been identified as the most appropriate imaging tool due to its consistent and high-quality data, compared to LIDAR which offers detailed height and canopy information but inconsistent data sets. The objective is to map the type, locations and height of existing green spaces using the data provided by aerial photography. Most cities are photographed annually and regional centres at least every two years, making it reliable and temporally comparable data.
To contribute to long-term urban greening strategies, the framework aims to establish a dashboard that can monitor urban green space over time. This will ensure that policy decisions are relevant and tailored to each city. Mapping the positive correlation between green space and liveability measures such as cooling, pollution/emission abatement, and human health, will inform future urban greening initiatives. CAUL Hub anticipates that a robust framework to support urban greening nationally will exist by mid-2018. This framework will operate at the intersection of evidence and policy, aiming to accelerate the impact of research, facilitating transparent and efficient environmental actions.
The extent to which the project continues will depend on funding acquired to support national implementation.
Indigenous Advisory Group Update
The Indigenous Advisory group met on the 28th of September and appointed the new co-chairs Jason Barrow and Maddison Miller. Jason is the Cultural Awareness officer at KurongKurl Katitjin at Edith Cowan Uni (WA). Maddi is an archaeologist at Heritage Victoria and member of Indigenous Architecture and Design Victoria.
The IAG thanks outgoing chair Stan Lui for the enormous amount he achieved in his time as chair. Stan is a Torres Strait Islander from Erub (Darnley Island) which is located in the top eastern Torres Strait. Stan has moved back to the Torres Strait after living in Cairns with his large fleet of fishing boats.
Stan came to us from his work with the Tropical Water Quality Hub in the National Environmental Science Program and helped us develop the category system for assessing the potential for Indigenous Engagement and Participation for our research projects. This system places all research activities into one of three categories based on their potential for Indigenous Engagement and Participation, with consequent obligations on researchers for each category.
This category approach was recently presented to the International Association for Public Participation by Maddi Miller, co-chair of the CAUL Hub Indigenous Advisory Group (IAG), and Cathy Oke, Knowledge Broker. This presentation also featured the video produced by the CAUL Hub on Indigenous Knowledge in cities. In 2017, the CAUL Hub IAG will start work on updating this video into a Virtual Reality format.