DTEx: A dynamic urban thermal exposure index based on human mobility patterns.

Area of Science:

• Environmental Science
• Urban Planning
• Public Health

Background:

• Climate change exacerbates extreme heat events in urban areas, impacting resident health and comfort.
• Existing heat vulnerability indices lack dynamic human movement considerations.
• Understanding spatio-temporal heat exposure is crucial for effective mitigation strategies.

Purpose of the Study:

• To introduce a novel Dynamic urban Thermal Exposure index (DTEx) for assessing urban heat exposure.
• To integrate dynamic human movement patterns with heat hazard data.
• To provide a tool for identifying vulnerable urban locations during heat events.

Main Methods:

• Developed the DTEx by combining human movement patterns derived from anonymized smartphone data and heat hazard patterns from machine learning models using vehicle-mounted sensor data.
• Classified combined parameters using standard deviations to create the exposure index.
• Applied the DTEx in a mid-sized city to analyze spatio-temporal heat exposure patterns.

Main Results:

• The DTEx effectively identified high-temperature spots linked to significant foot traffic, such as shopping plazas.
• Heat exposure varied dynamically, with notable increases observed near a football stadium on a game day.
• The index ranged from 2 to 12, indicating varying levels of thermal exposure across the urban environment.

Conclusions:

• The DTEx offers dynamic heat monitoring, crucial for targeted heat mitigation in vulnerable urban areas.
• Integrating mobility and sensor data provides detailed insights into heat-exposed locations due to human congregation.
• This information is vital for urban planning, risk communication, and developing heat-resilient smart city strategies.