Human mobility in response to environmental hazards in China : new approaches to environmental inequalities

Abstract

Many geographic and health literatures highlight spatiotemporal uncertainties in the contextual influences arising from the mismatch between dynamic processes of mobility and static measurement of exposure, and seek to explain environmental disparities and disproportionate burdens of certain groups through the lens of spatial segregation (e.g. activity space-based segregation). However, those studies ignored the potential role of everyday mobilities in hazard adaptation and failed to explain the exposure disparities across populations residing and conducting activities in the same spaces due to different reactions to adverse environmental conditions. Besides, recent studies point out that place-based interventions (e.g. social mixing policies) do not necessarily reduce environmental inequalities, which conveys an urgent need to go beyond segregation-based explanations and rethink the changing significance of everyday mobilities in extreme, abnormal conditions. This study approaches this issue by reconceptualizing mobility as a response to environmental hazards, and hypothesizing that unequal risks (i.e. exposure to air pollution and cold extremes) can be (re)produced through facilitating everyday mobilities of the advantaged in avoiding harmful environmental impacts and marginalizing the disadvantaged. To expand the focus in health geographies from location-based to behavior-based, from one-hazard to more-than-one-hazard, from unequal exposures to unequal responses, and from single-scale to multi-scalar, four research questions are proposed: 1) How residents perceive and respond to adverse environmental conditions in their daily lives, and do they use mobility as an adaptation strategy to avoid or mitigate their exposure to environmental hazard (i.e. air pollution)? 2) Do different environmental hazards (i.e. air pollution and cold extremes) generate different patterns of mobility responses, and are there any interaction effects between two hazards that cause the combined effect to be amplified or attenuated? 3) How sociodemographic attributes and space-time constraints modify the use of mobility responses and thereby lead to the disadvantage(s) of certain group(s) 4) Would spatiotemporal scales affect the identification of mobility as a response? What are the ideal units for investigations of mobility under environmental hazards? The study conducts an analysis in the city of Chengdu, China using a mixed-method approach combing survey and large-scale mobile phone data. Based on a mixed mode survey in the central city of Chengdu, it first unfolds the multiple adaptation strategies of city residents confronting hazards (i.e. air pollution) and unveils the adoption of daily mobility (e.g. intercity and urban-rural mobility) as a risk reduction and adaptation strategy. Then, it expands analytical focus to the interaction effect of two different hazards (i.e. air pollution and extreme cold events) and the unequal mobility responses of social groups with divergent socioeconomic and demographic characteristics. The study detects the differentiations among populations by age, gender, hukou status, residential status, and travel purposes, and identifies the vulnerable groups that are least sensitive to risks. By linking human movements and environmental conditions at multiple spatial and temporal scales, the study further examines scale effects and decision making mechanisms of mobility response to hazards in space−time. The study contributes to geographies of health and place in the following five ways. First, it draws attention to the relevance of daily mobility in risk adaptation and integrates current debate on contextual effects and spatiotemporal uncertainties. Because mobility is both affecting and an outcome of environmental exposure, the personalized geographic contexts can be (re)constructed by mobility changes due to the experienced contextual influences. Second, the study finds the disparities in mobility responses among divergent social groups and sheds light on the dynamic nature and (re)production of environmental exposure inequalities, beyond the lens of residential and other spatial forms of segregation that is predominantly observed in American cities. Third, it provides a robust exploration on how the correlations between physical environmental conditions and daily mobility patterns are affected by spatiotemporal analytical scales, and identifies appropriate units for examination of mobility as a risk response. Fourth, it reveals that mobility response is moderated by sociodemographic differentiation and space-time constraints, which implies that environmental health inequalities among social groups could be reinforced. Only those who are originally advantaged can act in their everyday mobilities to avoid or mitigate hazard exposures, or indeed want to. Lastly, the findings of the study can inform public policies to provide hazards−health warnings and information for the vulnerable populations and to incorporate rapid impact assessment in identification of the disadvantaged and risk management. This study has the potential to evoke reflections on the limitations of recent geographic and health literature, because the effects of environmental exposure and resulting inequalities across individuals or populations could be underestimated if place effects are conceptualized without considering mobility and averting actions.