职住地建成环境对城市居民体力活动水平的影响及其机制研究

体力活动不足已成为影响城市居民健康的重要原因。因此，如何优化城市建成环境以提高居民体力活动水平不仅是城市地理学的前沿议题，也是健康城市规划的重要内容。但是，鲜有研究同时考虑职住地（居住地和就业地）建成环境与居民体力活动水平的非线性关联及其中介机制，致使当前健康城市规划缺乏科学依据以提出有效促进体力活动的措施。为此，本项目以上海市为例，收集问卷和建成环境数据，深入探讨职住地建成环境对城市居民体力活动水平的影响及其机制。首先，构建包含职住地建成环境的体力活动水平分析框架，梳理符合中国情境的职住地建成环境测度指标。然后，采用广义加性混合模型和机器学习方法，探究建成环境对体力活动水平的非线性影响与最优作用范围，并使用结构方程模型和中介效应分析的方法识别其影响机制。最后，总结研究发现并与国内外研究结果相比较，提炼共性规律，厘清结论差异的原因，进而提出提高居民体力活动水平的职住地建成环境优化思路。

Insufficient physical activity has become a critical reason to affect urban residents’ health status. Therefore, exploring how to optimize urban built environment to improve residents’ physical activity level is a frontier topic of urban geography and is also an important point of healthy city planning. However, few studies have considered the non-linear association between the built environment at both residences and workplaces on urban residents’ physical activity level and its influential paths, leading to healthy city planning lacking a scientific basis to put forward strategies to improve physical activity level efficiently. To bridge these gaps, this project will take Shanghai as an example to collect the physical activity and objective built environment data, and will explore the impact of residential and workplace built environment on physical activity level of urban residents and its mechanism. First, this project will construct an analytical framework of residents’ physical activity level that incorporates the built environment at both residences and workplaces, and will construct suitable built environment indicators in the Chinese context. Second, the project will examine the non-linear and threshold effects of residential and workplace built environment on physical activity level by employing generalized additive mixed models and machine learning approaches. Moreover, the project will explore the influential paths from the built environment to physical activity level by applying structural equation modeling and mediating effect analysis approaches. Finally, this project will summarize general laws of the associations between the built environment at both residences and workplaces and physical activity level by concluding the research findings, comparing with results from other studies, and identifying reasons for the differences of conclusions. The project will also put forward some ideas of optimization for built environment at residences and workplaces that can improve people’s physical activity level effectively in the Chinese context.