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Human Mobility Flows

In response to the soaring needs of human mobility data, especially during disaster events such as the COVID-19 pandemic, and the associated big data challenges, we develop a scalable online platform for extracting, analyzing, and sharing multi-source multi-scale human worldwide mobility flows. Within the platform, an origin-destination-time (ODT) data model is designed to work with scalable query engines to handle heterogenous mobility data in large volumes with extensive spatial coverage, which allows for efficient extraction, query, and aggregation of billion-level origin-destination (OD) flows in parallel at the server-side. An interactive spatial web portal, ODT Flow Explorer, is developed to allow users to explore multi-source mobility datasets with user-defined spatiotemporal scales. To promote reproducibility and replicability, we further develop ODT Flow REST APIs that provide researchers with the flexibility to access the data programmatically via workflows, codes, and programs. Demonstrations are provided to illustrate the potential of the APIs when it is integrated with scientific workflows and with the Jupyter Notebook environment. We believe the platform can assist human mobility monitoring and analysis during disaster events such as the ongoing COVID-19 pandemic and benefit both scientific communities and the general public in understanding human mobility dynamics.

Architecture of the ODT Flow platform

All OD flows are downloaded in CSV (Comma-Separated Values) format.

  • o_place: id for the origin of the flow (using FIPS for places for US county and tract, using ISO place code for other places).
  • d_place: id for the destination of the flow (using FIPS for places for US county and tract, using ISO place code for other places).

Data updates:

  • Twitter-based flows are available from 01/01/2019 to 12/31/2020
  • Safegraph-based flows are available from 01/01/2019 to 04/15/2021 (updated on April 18, 2021)
Statistics of the derived daily OD flows from Twitter data and SafeGraph data
SafeGraph-derived county population flows to New York County from (a) 03/08/2020 to 03/14/2020 and (b) for the following week (03/15/2020 to 03/21/2020). Twitter-derived in & out flows between England, UK and other first-level administrative units in the Europe area for (c) 01/01/2020 to 02/29/2020, and (d) 03/01/2020 to 04/30/2020
Daily population movement in different geographic scales. (a). Intraflow for Spain (top line) and Argentina (bottom line) in 2019 and 2020; (b) Inflow for New York County, U.S. in 2019 and 2020; (c) Intraflow for a census tract in Columbia, South Carolina (mainly located within the University of South Carolina) from 01/01/2019 to 02/24/2021; (d) Interflow (In&Out) for a census tract in a residential area of Columbia from 01/01/2019 to 02/24/2021.