Applying Circuit Theory and Risk Assessment Models to Evaluate High-Temperature Risks for Vulnerable Groups and Identify Control Zones

Rapid urban development has exacerbated heat events. Vulnerable groups, due to deficiencies in physical functions and social support, often face higher health risks and survival pressures during heat events. Effectively identifying and assessing the heat risks they face and developing effective management strategies still pose many challenges. This study develops a heat risk assessment model based on the “hazard–accessibility–vulnerability” framework, incorporating circuit theory modeling to assess the health benefits of ventilation corridors for vulnerable populations and identifying high-temperature risk areas to better support science-based planning. The results show the following: (1) The urban heat island levels in the study area were classified based on the mean-standard deviation method, identifying that high-level heat islands account for 14.2% of the total area, with surface temperatures in urban built-up areas being significantly higher than in rural areas. (2) Based on the circuit theory model, 54 ventilation corridors were identified and 12 major corridors and 42 minor corridors were determined. (3) Based on the thermal risk assessment model, five residential areas covering 1.45 km2 were identified as having the highest thermal risk, and 5.68 km2 of residential areas had an imbalance between the ventilation demand and ventilation supply for vulnerable populations. This study innovatively assesses the health benefits of urban ventilation corridors from a social equity perspective and proposes urban renewal strategies such as introducing ventilation corridors, adjusting building layouts, enhancing green infrastructure, and promoting cooling technologies, offering new insights for future research.