Simulating the impact of ventilation corridors for cooling air temperature in local climate zone scheme

Abstract

Climate change and urbanization are impacting urban microclimates, necessitating careful consideration in urban ventilation planning. However, there remains uncertainty regarding the identification and examination of urban ventilation corridors (VCs), and their mechanisms for urban heat mitigation. This study combined ENVI-met and the least-cost path (LCP) algorithm to simulate the VCs within the local climate zone (LCZ) scheme, with Guangzhou as an example. The results show that (1) VCs constructed using the LCP method are primarily distributed along vegetation and rivers, bypassing high-temperature aggregation in high-density/high-rise building areas; (2) The cooling effect of VCs varies across different LCZs, influenced by factors such as land use, vegetation, building, and topography. (3) In low-density, low-rise LCZs, VCs significantly reduce temperatures by about 0.23°C, while in high-density, high-rise LCZs, the cooling effect is weaker, with a reduction of only around 0.01°C. This study highlights the importance of preserving hydrological system and optimizing green space layout to enhance urban ventilation thus mitigate heat accumulation.