Resilience patterns of human mobility in response to extreme urban floods

Junqing Tang; Pengjun Zhao; Zhaoya Gong; Hongbo Zhao; Fengjue Huang; Jiaying Li; Zhihe Chen; Ling Yu; Jun Chen

doi:10.1093/nsr/nwad097

Resilience patterns of human mobility in response to extreme urban floods

Natl Sci Rev. 2023 Apr 11;10(8):nwad097. doi: 10.1093/nsr/nwad097. eCollection 2023 Aug.

Authors

Junqing Tang^{1

2}, Pengjun Zhao^{1

2

3}, Zhaoya Gong^{1

2}, Hongbo Zhao⁴, Fengjue Huang¹, Jiaying Li¹, Zhihe Chen¹, Ling Yu¹, Jun Chen⁵

Affiliations

¹ School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
² Key Laboratory of Earth Surface System and Human-Earth Relations of Ministry of Natural Resources of China, Shenzhen Graduate School, Peking University, Shenzhen 518055, China.
³ School of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
⁴ Key Research Institute of Yellow River Civilization and Sustainable Development & Collaborative Innovation Center on Yellow River Civilization, Henan Province and Ministry of Education, Henan University, Kaifeng 475001, China.
⁵ Key National Geomatics Center of China, Beijing 100830, China.

Abstract

Large-scale disasters can disproportionately impact different population groups, causing prominent disparity and inequality, especially for the vulnerable and marginalized. Here, we investigate the resilience of human mobility under the disturbance of the unprecedented '720' Zhengzhou flood in China in 2021 using records of 1.32 billion mobile phone signaling generated by 4.35 million people. We find that although pluvial floods can trigger mobility reductions, the overall structural dynamics of mobility networks remain relatively stable. We also find that the low levels of mobility resilience in female, adolescent and older adult groups are mainly due to their insufficient capabilities to maintain business-as-usual travel frequency during the flood. Most importantly, we reveal three types of counter-intuitive, yet widely existing, resilience patterns of human mobility (namely, 'reverse bathtub', 'ever-increasing' and 'ever-decreasing' patterns), and demonstrate a universal mechanism of disaster-avoidance response by further corroborating that those abnormal resilience patterns are not associated with people's gender or age. In view of the common association between travel behaviors and travelers' socio-demographic characteristics, our findings provide a caveat for scholars when disclosing disparities in human travel behaviors during flood-induced emergencies.

Keywords: Zhengzhou flood; disaster resilience; human mobility; mobile phone data; urban flood.