Introduction

For urban metabolism researchers, obtaining data is one of the most important and time-consuming activities. This not only limits research activities, but it also creates a significant threshold for policy makers and others interested in using urban metabolism on a more practical level. The inconsistency and scattered nature of data furthermore complicate the uptake of urban metabolism tools and practices.

Metabolism of Cities has launched a new project called MultipliCity to try and take on this challenge. MultipliCity aims to develop a global network that maintains an online hub to centralize, visualize, and present datasets related to urban resource use and requirements. A network of local volunteers (students, researchers, city officials, citizens, etc) assists with the identification of relevant datasets, and the MultipliCity platform takes care of indexing, processing, and standardizing the datasets. This allows for a large collection of in-depth data to become available to researchers and the general public, vastly improving access and allowing for more work to be done on analysis and interpretation, rather than on data collection.

Platform Development
Multiplicity is currently being developed by Metabolism of Cities. Using past experience and already identified datasets, the following baseline themes have been provisionally identified to house the different datasets: 1) biomass, 2) fossil fuels, 3) metals, 4) non-metalic minerals, 5) water, 6) infrastructure, 7) research, 8) policies, 9) electricity, 10) population. A number of frontrunner cities are being included in the pilot version of MultipliCity. Existing datasets from these cities are used to develop urban metabolism profiles. This process entails the following steps:

For each data topic (e.g. water consumption, electricity use, road construction) one or several common formats is identified.
Datasets are collected and the raw data is indexed (including the original spreadsheets and metadata including data quality indicators).
Scripts are written to process the raw data to the common format.
The processed data is uploaded to a master database, together with data on the same topic from the other cities.
Within each city profile, a set of tools is made available to explore this data

The following tools are being developed within each city portal:

Filtering tools: users can quickly and easily filter data by time period, type of data, geographical area, and other parameters.
Interactive visualisations: data is presented as bar/line charts, or other charts where appropriate, allowing users to interact with the data. These graphs become part of the theme’s page within the city profile, so that users can immediately get an idea of the underlying data without having to download any information.
Mapping tools: georeferenced data (especially data on micro-territorial unit scale) is displayed on a map and can be clicked on and browsed with a few clicks.
Downloading tools: multiple options exist for downloading data. Raw data, calculations, metadata, and the processed data can all be easily downloaded in different formats. Users can also filter or otherwise restrict or expand datasets before downloading them.

Who can use MultipliCity?

In line with Metabolism of Cities' core values, MultipliCity is a free, open source platform that is accessible to anyone. Metabolism of Cities has identified the following possible target audiences for MultipliCity:

Students, researchers and academics: data and insights from the platform can be used to better understand the material stocks and flows in the city and to run MFA, LCA, or other analyses using the data.
City officials: the city dashboard can be used to explore the city's dependence on resources and its sustainability challenges and opportunities.
Practitioners in the field of urban sustainability: people working in particular fields (e.g. around water infrastructure, construction materials, or food) can easily find in-depth data on their city or cities of interest. Furthermore, people working with non-profits, think tanks, or consultancy firms can use the platform to filter and locate that they need for their projects.
General public: the easy-to-use interface allows the general public to explore the material flows and stocks in their city and to see how this relates to sustainable practices, to understand how they can make a difference, and how things compare with other cities.

View prototype

Cape Town, South Africa