Intelligent extraction of urban ventilation corridors based on region growth algorithm with restricted direction

Rapid urban developments have resulted in numerous environmental challenges, including severe air quality and heat island effect problems. The construction of urban ventilation corridors provides an effective solution for enhancing air circulation and reducing the heat island effect. The present study focuses on Nanhu District, Jiaxing City, Zhejiang Province, employing Unmanned Aerial Vehicle tilt photography to obtain high-resolution urban remote sensing data and create a three-dimensional digital model of the city. Wind direction and speed over the past decade were analyzed in the proposed study area. Dominant wind directions were identified for both summer and winter seasons to calculate frontal area density under dominant wind directions, while an area growth method was applied with limited direction to determine urban ventilation corridors. The experimental results show two ventilation corridors under the winter-dominant wind direction and four under the summer-dominant wind direction. The results were validated against fieldwork conducted by three urban planning experts, with an error rate of 4.91% and 4.57% on a digital map. Eventually, this study will provide a tangible scientific foundation and technical support for the planning and construction of urban ventilation corridors to mitigate the heat island effect and improve air quality.