- Background & Vision
- Enter… Modelling
- Core Philosophy of UrbanBEATS
- Overview of the UrbanBEATS-PSS
- Ongoing Development and Testing
Background and Vision
The Urban Biophysical Environments and Technologies Simulator (UrbanBEATS) is an integrated modelling tool designed to support the planning of sustainable, liveable and resilient cities. With the ongoing challenges of urbanisation and population growth, climate change, biodiversity loss and, more recently, the SARS-CoV-2 pandemic, cities are facing a growing list of challenges to adapt. It is widely recognised that solutions in cities can no longer be mono-functional. Designing with nature and biomimicry have long been recognised as attractive, sustainable and resilient solutions. Planning and design to maximise provision of ecosystem services, namely goods and services that satisfy human needs directly and indirectly while protecting the natural environment is increasingly recognised. This approach is inherently interdisciplinary, drawing upon a rich body of knowledge and experience beyond simple engineering or urban planning. An integrated approach is essential if we want to deliver smarter solutions that are adaptable to the uncertain future.
Urban Water Management offers many opportunities to help cities achieve multiple ecosystem services through smart management of the water cycle. In particular, Blue Green Systems are nature-based solutions that allow the provision of a wide range of multiple ecosystem services and benefits to cities and their natural environment. The concept has existed for decades and has taken many shapes and forms across the globe, including Water Sensitive Urban Design (WSUD), Green Infrastructure (GI), Low Impact Development (LID) and Sponge Cities among other names. Due to different historical and cultural drivers, such systems are diverse, ranging from smarter spatial planning, to inter-connected urban green spaces, decentralised stormwater management technologies (e.g. bioretention systems, constructed wetlands, infiltration systems) and a whole suite of non-structural tools including policy, legislation and behavioural change. The way we manage water in cities is evolving rapidly (see Fig 1), from traditional provision of water supply to sanitation and drainage, environmental protection. Over the last decade, the idea of the Water Sensitive Cities paradigm has been a hot topic, underpinned by three core pillars: (1) cities as water supply catchments, (2) cities providing ecosystem services and (3) cities with water sensitive communities.
Modelling tools are attractive means of supporting the planning process as they provide virtual laboratories to allow planners and other stakeholders to test hypotheses and ideas that are important to their decision-making. These virtual laboratories allow testing of ideas, evaluation of how differences in stakeholder objectives and opinions may result in different design solutions (if at all) and automate otherwise laborious tasks of assessing opportunities and constraints surrounding our design space. UrbanBEATS provides such a platform that brings together the different city-scale, regional and neighbourhood solutions, be it policy and regulation, spatial planning or technological options. Rather than a prediction, the model instead opts for the exploration of the interactions between policy, urban form, technological solutions and stakeholder preferences. Its usefulness lies in its ability to facilitate discussion among stakeholders and to yield new insights into the potential multiple benefits and consequences of key decisions surrounding the planning towards a Blue Green City.
Core Philosophy of UrbanBEATS
The UrbanBEATS acronym stands for two things. Not only is it (at its core), the Urban Biophysical Environments And Technologies Simulator, a tool that brings together the biophysical environments and its associated technological solutions through simulation. At the higher level, it is also the Urban Benchmarking, Exploration And Transitions Simulator. This alternative name reflects the three dominant ways in which it can be used.
- BENCHMARKING: Being able to test new solutions in relation to the current ‘business as usual’ or ‘status quo’. By benchmarking alternative planning scenarios against the current city state, model outputs can demonstrate to what extent new ideas can improve upon the current state. Conversely, it can also demonstrate the extent to which grand challenges (e.g., urbanisation, climate, biodiversity loss) can impact our city’s current performance.
- EXPLORATION: The model is built upon the philosophies of exploratory modelling, the ability to generate a wide variety of alternatives against a set of model inputs and explore these as an ensemble. Exploratory modelling has been an effective means of model-based decision-support, be it in the policy space or in the infrastructure planning space.
- TRANSITIONS SIMULATION: Cities are dynamic, planning is dynamic. Adaptive management encompasses the idea of making decisions, learning from their impacts and revising or adapting these to suit new conditions. This progressive approach allows flexibility and more proactive solutions to planning. Be it in how the land use of a city changes or in how quickly Blue Green Technologies are implemented into a growing urban space.
Whilst UrbanBEATS can model a whole range of aspects surrounding the urban environment, it is not intended to be a ‘model of everything’. In fact, the design of UrbanBEATS is modular, based on a flexible but simplified spatial representation. Any simulation should have clearly defined modelling aims, allowing for key modules to be selected and outputs to be generated in a time efficient manner without unnecessary information overload. Analysis paralysis is unwanted when making key decisions and UrbanBEATS provides the means of conducting extensively integrated studies, but also light-weight rapid assessments of specific aspects (e.g., pollution management, enhancing urban amenity).
Overview of the UrbanBEATS-PSS
UrbanBEATS is an integrated spatio-temporal model capable of simulating regions ranging from small neighbourhoods of around 5km2 up to larger regions of 1200km2. Larger case studies have been tested (e.g., we have managed to run Greater Metropolitan Melbourne – 9000 km2 – in the model, but with limited options so these numbers will remain fluid as development progresses). It spatially maps urban characteristics, landscape connectivity (a number of different types of networks) and geopolitical information and uses these to investigate potential opportunities for Blue Green Systems, from city-wide policies down to lot-scale technologies. The model structure is shown below in Fig 2. There are four core processes that constitute the model’s core loop: (1) General spatial representation, (2) Abstraction of urban form, (3) Spatial mapping, assessment and policy experimentation and (4) Evaluation of system performance. These are supported by individual modules that simulate a number of different aspects such as urban development and the placement/retrofit of water infrastructure (predominantly Blue Green Infrastructure).
The amount of input data that the model requires varies depending on the type of simulation that needs to be undertaken. At is core, three essential spatial input raster maps are required to begin working with the model: land use (following a water-centric classification scheme), population (either as a total value or density) and elevation. Our recommendation is to use a 10m input raster resolution. Additional input maps including shapefiles of geopolitical boundaries (municipalities, suburbs or user-defined planning zones), natural features (e.g., soil, groundwater depth, rivers, lakes), existing urban infrastructure (e.g., road networks) and planning-related information (e.g., overlays) may be required depending on modelling aims and the complexity of the case study. Some inputs provide the model additional information to work with while other inputs are essential for some of the core algorithms. In some cases, temporal data is not necessarily required as UrbanBEATS can also be used to conduct a purely spatial analysis. However, climate data and other temporal information can help the model provide a more dynamic insight into the case study being investigated.
UrbanBEATS outputs a range of shapefiles, which can be visualised in conventional Geographic Information System (GIS) tools such as ArcMap or QGIS. These can serve as a springboard for enriching stakeholder discussions and better understanding the ‘look and feel’ of the case study.
UrbanBEATS is designed to work with minimal data inputs. As such, to avoid challenges in obtaining detailed spatial maps of urban areas (e.g., exact road alignments, buildings, parcels), the model simplifies spatial representation or a conceptual grid structure. UrbanBEATS uses the concept of ‘Blocks’, which represent local neighbourhoods across the urban area (see Fig 3 for an illustration of the idea). A ‘Block’ is the smallest spatially explicit unit in the model, it is what users will see in the output map. Each ‘Block’, however, contains rich information about the urban area within the delineated region and is thus not simply a raster map, but rather a geodatabase of model information. This ‘Block’-based structure was inspired by models such as UrbanSim. Currently, three different representations are possible: Square cells, hexagonal cells and land use patches (i.e., irregular shapes that represent a single land use). To complement this representation, UrbanBEATS also establishes a number of broader regional relationships between ‘Blocks’, in particular, water flow paths, local context (e.g., municipalities and suburbs that each ‘Block’ belongs to, spatial connectivity between ‘Blocks’ through urban green space).
Despite this simplified representation, the model maintains information on the characteristics and relationships at various spatial scales (see Fig 4), from the overall city down to the individual lot. To accomplish this, it uses the input data to generate an abstraction of the urban form, i.e., characteristics about buildings, allotments, pervious and impervious surface coverage across the entire landscape. This provides all essential information for conducting a range of analyses including the design of decentralised infrastructure for achieving a range of stormwater management objectives and improving urban hydrology to analysing the spatial connectivity for humans and animals.
More information on how UrbanBEATS processes the spatial inputs and represents the urban form can be found in Bach et al., 2018. The algorithms is based on a procedural approach that uses parameters representing statutory planning rules to recreate a representation of urban form for different land uses, from low and high-density residential developments to industrial and commercial estates among others.
Planning of Blue Green Systems
Due to the diversity of Blue Green Systems, ranging from decentralised technologies to strategic spatial planning of landscape connectivity and city-scale policy, their planning the model is not contained in a single module. To date, UrbanBEATS can plan a range of decentralised technologies for three different stormwater management objectives (runoff volume reduction, pollution management and provision of alternative water supply through stormwater harvesting). The concept is based on the sizing of a system according to catchment characteristics and potential location and determining whether it fits in the landscape (see Fig 5). Through a Monte Carlo process, UrbanBEATS can generate thousands of potential technological combinations that are filtered down to a handful of feasible and ‘preferred’ solutions (based on stakeholder preferences). More information about this process is available in Bach et al., 2020.
The approach we use to locate and size such technologies and the list of available technologies (current limited to bioretention systems, infiltration systems, constructed wetlands, ponds and basins, swales and rainwater tanks) are undergoing refinement. Recent developments such as the creation of a spatial suitability analysis tool SSANTO and the investigation of spatial connectivity are guiding this research towards a more rigorous spatial approach which we hope to showcase soon.
Apart from decentralised technologies, ongoing work is looking at how we better can incorporate the spatial planning aspect and more objectives into the model to allow for multi-functional aspects of Blue Green Systems to be designed and not just assessed. For example, we are investigating the use of a rapid microclimate model that can simulate urban heat across our case study to identify hot spots, a functional connectivity model to understand where the pinch points to species movement and vulnerability are and an urban model to simulate changes in land use guided by Blue Green policies. You can view our various ongoing projects for more information about the current research that will inform the future of UrbanBEATS.
Evaluation of System Performance
System performance assessment provides decision-makers a range of performance indicators for better understanding the implications of certain decisions. UrbanBEATS links with a range of state-of-the-art models including SWMM and MUSIC, two widely used packages for the simulation of urban drainage and Blue Green Infrastructure and EPANET, a water distribution system model. Based on UrbanBEATS’ unique spatial structure, we are also currently developing a spatial total urban water balance model that can provide users with immediate information on the water fluxes within the development. Links with urban microclimate and biodiversity assessment models are current topics of ongoing research.
Using the Model
With the support of UrbanBEATS, users can explore a wide variety of questions surrounding the planning of Blue Green Cities. Here are some specific examples that one could ask the model:
- How would feasible water management strategies for a variety of multiple objectives look like in my urban environment?
- Which locations within my urban area are most suitable for delivering various water management objectives?
- What impact will urban growth and climate change have on my urban water system and what specific solutions could I use to adapt to these?
- How will decentralised strategies impact the existing centralised water infrastructure in my urban catchment?
- How similar/dissimilar are water infrastructure when considering different stakeholder preferences?
- How can we combine policy and regulatory action to mitigate adverse pollution and urbanisation impacts?
- How can I leverage Blue Green technologies and smarter spatial planning to bridge the connectivity between urban and rural regions to support biodiversity?
Ongoing Development and Testing
This website aims to provide you up-to-date information on the development of UrbanBEATS as well as access to the model as it becomes operational. Ongoing developments and testing are constantly underway and the research and development team is constantly evolving with new contributors as time passes. The intention is for UrbanBEATS to also be widely applicable. As such, we are testing the model and its various features on a number of case studies around the world.
UrbanBEATS is being developed as a Desktop software and is coded in the Python language using an extensive collection of libraries for geospatial data handling and scientific computing. It is being developed as a standalone, but using data formats that are compatible with other software such as GIS tools like ArcMap and QGIS. There are two versions of the model: (1) a legacy version, which was developed as part of the original PhD and extended until 2017 (no longer being maintained) and (2) the current version, where the model was completely rebuilt from the ground up with a new user interface (see Fig 6) and a better data and simulation management feature. This version is currently still being maintained, but we hope that within 2021, a downloadable build will be available for testing.
Head over to the ‘legacy version’ page if you would like to gain some insight into the general idea of the model. We have included some basic tutorial and data set to help you get started, but note that this older version is no longer being maintained as all our efforts are devoted to getting the new version up and running sooner than later. Should you have any questions, however, we will maintain an FAQ list on the page and are happy to answer any queries you may have.
The Research & Development Team
The UrbanBEATS research and development team currently encompasses nine different research institutions across five countries (Switzerland, Australia, Canada, Austria and The Netherlands). The research and development team is highly interdisciplinary ranging from urban water engineering to urban planning, integrated modelling, ecology and the environmental and social sciences. You can view all active participants and past contributors over at the R&D Team page for more information. Project pages and case studies will provide an overview of who is involved where.
Ongoing Projects and Case Studies
There are a number of ongoing research projects supported by various funding schemes. Each of these projects usually addresses a sub-topic and strives to develop new or enhance existing models in UrbanBEATS. We have provided a brief summary of the various projects on each of their respective pages including relevant publications that have resulted from the research. You can also find a list of publications relating to UrbanBEATS and which have inspired UrbanBEATS’ development over at the Publications page.
There are a number of case studies that UrbanBEATS is being or has been on in Switzerland, Australia, China, Canada, USA and Austria. You can check out each case study on this website including any related publications that these are featured in. For more specific information about them, feel free to get in touch with us.