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Isolation, stress and urban resilience: A network analysis approach

Five billion geotagged tweets collected over the last five years provides a unique dataset for studying urban resilience. A team of Northeastern professors will leverage this publicly available Twitter data to examine the resilience of geosocial networks, incorporating the movements of urban dwellers. Isolation, a main factor of stress that threatens urban resilience, is not only determined by where you live, but how you live, the researchers stress.

“Where people are living doesn’t reflect the entire story,” says Qi Ryan Wang, an Assistant Professor in Civil & Environmental Engineering.  With funding for two years from the Global Resilience Institute (GRI), Urban Geosocial Network Resilience brings together co-PIs Wang and Jianxi Gao, an Associate Research Scientist with Northeastern’s Center for Complex Networks.

Pedestrians [Pixabay.com/CC0 Public Domain]The team will examine urban mobility from this network perspective, with the goal to understand – and quantify – its influence on urban neighborhood resilience.

“Urban isolation, a main factor of stress that threatens urban resilience, is central to the debate of social inequality,” the researchers explain.

The public Twitter data that they will be using comes from the 50 largest U.S. population centers, with each geotag containing the exact location of where the tweet was posted.

The dataset was initially compiled by Wang in 2012 and expanded by a collaboration with the Center for Geographical Analysis (CGA) at Harvard University.

“Overall, the analyses will allow us exploring how different types of perturbations in and between urban neighborhoods can impact the resilience of the urban geosocial networks and how the phenomenon is related to the fundamental issues of social isolation and segregation” -Wang and Gao

Wang describes the data tracking as an ongoing effort.

Using the urban mobility data, the team aims to understand how human movements are related to issues such as segregation and isolation. Wang brings expertise in urban and social resilience as well as geo-social networking and Gao specializes in the resilience of complex networks.

“During my research I got to know Jianxi and learn about his work and thought it could be a very good extension from what we were trying to do,” says Wang. “I think this is a very important topic because people connect; if you see how people move across different neighborhoods, you can build strong networks.”

Gao adds, “I had not studied the network of communities in a city before. Because Ryan has this data about community mobility, it made possible a very interesting opportunity for studying this type of network.”

The team’s network analysis approach will examine urban resilience in a new way with the hopes they can help communities to better understand, predict and manage factors affecting urban resilience. With this aim in mind, the project has three objectives:

  1. Integrating large-scale urban informatics to examine urban mobility and the emerged geosocial networks;
  2. Systematically simulating different types of perturbation to urban geosocial networks;
  3. Quantifying the impact of the perturbations on urban neighborhoods.
Geosocial Network in Boston
Source: Urban Geosocial Network Resilience | Qi Ryan Wang / Jianxi Gao

In a preliminary study, Wang and Gao used a unique dataset of over 20 million geotagged tweets from Boston and studied the mobility network over a period of 18 months, They then overlaid those coordinates on the 2007-2011 ACS Community Survey map to find which block groups were visited. Out of this research, they built the mobility networks, before simulating perturbations and determining which of the 50 neighborhoods caused the most changes in the resilience score – whether up or down.

Building on this work, the researchers will expand the project into the 50 largest cities in the U.S., constructing geosocial networks using the geotagged Twitter data and simulating three types of perturbations before analyzing and reporting the results.

“What we are trying to do is really understand the stress part of the story in urban resilience and how we can quantify that, and maybe provide some solutions,” says Wang. “The driver on this research is to show people that social isolation has a big impact, a big stress on our urban resilience and it’s going to be like that for a long, long time. We have to realize that we need to start doing something to help this situation. That’s a fundamental driver from our perspective.”

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About the GRI:
The Global Resilience Institute (globalresilience.northeastern.edu) is leading a university-wide interdisciplinary effort to advance resilience-related initiatives that contribute to the security, sustainability, health and well-being of societies. Our objective is to help advance preparedness at multiple levels to effectively respond to slowly emerging disruptions and sudden disasters, both human-made and naturally-occurring. To learn more about the seed-funding program, click here.

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