Heat & Tweet: A Multi-City Study of Outdoor Activities and Thermal Comfort in Open Spaces Using Social Media Data

Dr Huang, Jianxiang   (Principal Investigator)

5

2018-07-01

56000

Heat & Tweet: A Multi-City Study of Outdoor Activities and Thermal Comfort in Open Spaces Using Social Media Data

Adaptive Urban Planning, Open Space, Outdoor Activities, Outdoor Thermal Comfort, Social Media

Building and Construction,Urban Studies and Planning

N/A

Seed Fund for Basic Research for Resubmission of GRF/ECS Proposals

2018

Completed

Heatwave events and Urban Heat Island Effects (HUIE) threatens human health and behaviours for cities globally and in particular high-density cities such as Hong Kong. Heat stress disrupts the perception of comfort and outdoor activities such as walking, exercising, engagement or enjoyment of a place. The issue is of growing importance to urban planners and policy makers since a vibrant and enjoyable open space is a measure of planning success. While research evidence suggests that the thermal environment of an open space is closely linked to outdoor activities and thermal comfort [1], the range of acceptable outdoor thermal conditions remains inconclusive. Researchers disagree on outdoor thermal comfort conditions across society, culture and climate as well as the extent of adaptive actions. Most studies measure behaviors and perceptions using observations or questionnaires. Findings are often limited by sample size, study period and the number of sites available. Results are not generalizable across climate zones. Attempts to combine existing dataset across climate zones achieved limited success. Availability of GSM (Geotagged Social Media: Twitter) data offers new opportunities for exploratory research on human behaviors and perception. We aim to establish a holistic understanding of the influence of thermal environment on outdoor activities and thermal comfort in open spaces in 22 cities across climate zones using space-time analysis. Research effects include 1) charting GSM activities and sentiment response to heatwaves and fluctuations of thermal environment in open spaces; 2) identify the range of acceptable outdoor thermal conditions using text-mining and topics analysis; 3) invite community and students from the PI & Co-Is’ institutions to join open space tours and capture real-time tweets and response as they are exposed to a diversity of thermal environment in micro-scale. Results will be cross-checked with data from existing benchmark studies. The project is an extension of the PI’s ongoing research on social media analytics, outdoor thermal comfort, urban climate and microclimate. The study is expected to enrich literature by developing a heat-exposure-response curve based on GSM data; findings are relevant to adaptive urban planning, UHIE mitigation policies, and personal weather services. The study is relevant and timely for Hong Kong, a city of rising UHIE, frequent heatwave events, and growing vulnerability in light of climate change. The city is top-ranked in internet connection speed, smart phone and social media penetration [2], making it an ideal home for social media-based research.