Urban–rural disparities in flood-driven relocation behavior: spatiotemporal evidence from Zhengzhou

Flood disasters have intensified due to climate change and rapid urbanization, and they are increasingly reshaping the spatial dynamics of population behavior. Cities have grown more complex and heterogeneous, and effective disaster preparedness demands a nuanced understanding of how populations across diverse urban typologies respond to hazard exposures. However, existing research has largely overlooked urban–rural disparities in relocation patterns during pluvial flood events, failing to capture the spatial heterogeneity of displacement and resettlement behaviors across different settlement contexts. To address this gap, anonymized mobile phone signaling data were used to investigate population relocations during the July 2021 flood in Zhengzhou, China. The analysis revealed a pronounced outward relocation trend from high-density urban cores toward the suburban and rural peripheries. This result demonstrated a temporary reorganization of the urban spatial structure under acute flood stress. The relocation intensity and directional concentration increased across all zones, including urban, peri -urban, and rural areas, but the average displacement distances varied. Urban residents tended to relocate over longer distances, whereas rural populations exhibited shorter relocation distances and more localized movements. The results of a multi-scale geographically weighted regression indicated that these inter-community differences were primarily shaped by the following environmental factors: river proximity, elevation, and surface water coverage. These results underscored the critical role of natural geographic conditions in shaping spatial inequalities during disaster-induced population mobility shifts. The results highlight the need to incorporate density-sensitive distinctions and localized environmental risks into adaptive, behavior-aware disaster preparedness and urban resilience strategies.