The above figure illustrates individual mobility perturbation in visited locations under extreme weather events. The results show that, influenced by extreme weather events, people tended to visit fewer places and make fewer travels, reflecting that extreme weather events would restrict people’s movements.

The above figure describes the analytical framework for individual mobility perturbation under extreme weather events. The framework includes three main modules, namely describing individual mobility patterns, assessing individual mobility perturbation and exploring individual variation of mobility perturbation. Based on the framework, individual mobility perturbation could be assessed from the perspective of visited location, movement range, waiting time and movement status. Moreover, this framework could support the identification of typical patterns of individual mobility perturbation.

The trajectories of two anonymous individuals, classified as 2-returner and 2-explorer respectively, over one week are shown in the figure to illustrate the typical difference between these two classes of individuals. By analyzing the daily trajectory data of 21,240 individuals in Guangzhou over 111 weekdays, this study evidenced that the returners and explorers dichotomy is significantly dependent on the duration within which individuals’ trajectories are observed.

Using a systematic review approach, existing mobility-driven urban studies are classified based on whether they interpret urban mobility as spatial movements, a social phenomenon, an economic indicator or a policy tool. The aim of this study is to reveal the complexity and multiplicity of human mobility concept for various urban application scenarios.

To quantitatively assess human mobility perturbation, this study proposes to measure both the instantaneous perturbation at any given moment during an EWE, and the accumulated perturbation over the entire timespan of the EWE based on the RTD metric.