Dynamic greenspace exposure and residents' mental health in Guangzhou, China: From over-head to eye-level perspective, from quantity to quality

Natural environments especially greenspace may play an important role in enhancing people's mental health. However, the existing literature mainly assesses greenspace exposure in people's residential neighbourhood ignoring the dynamic nature of daily movements and residential histories. Also, most research assesses greenspace from an 'over-head' perspective whereas an 'eye-level' perspective may better capture people's experiences of greenspace, including its quality. We examine the importance of capturing people's eye-level greenspace exposure across different places people occupy in their everyday lives. We construct four measures of greenspace capturing overhead (NDVI), eye-level quantity and quality (Street View Greenness (SVG)) and self-reported neighbourhood greenness exposure. First, we assessed greenspace exposure in residential neighbourhoods, workplaces, recreational places, mobility path and previous residential neighbourhood. The four greenspace indicators were not associated with each other, suggesting they capture different aspects of greenspace. Second, we examine the associations between dynamic greenspace exposure and residents' mental health using survey data collected from 26 neighbourhoods of Guangzhou, China. The results show that all measures in residential places are associated with mental health. However, only SVG-quality in recreational places is positively associated with mental health, while both SVG-quantity and SVG-quality in participant's mobility path are associated with mental health. Our findings demonstrate eye-level greenspace quality is more important in relation to mental health. Policymakers and planners should focus not only on residential neighbourhoods, but also consider the wider environments that people encounter in their everyday lives.