Wind environment assessment and planning of urban natural ventilation corridors using GIS: Shenzhen as a case study

Abstract

The development of high-density cities has aggravated the harshness of the urban microclimate in face of global warming. However, an adequate urban ventilation system can introduce clean and cool air into high-temperature areas of a city, which can alleviate the urban heat island (UHI) effect and increase residents' thermal comfort. In this study, we devise an integrated air ventilation assessment (IAVA) method to assess the urban wind environment using multi-source data, with Shenzhen as an example. The IAVA map illustrates that developed areas in the south and west of Shenzhen form a “wind wall” that reduces wind speeds and prevents wind flow into inland areas. In light of the results of the IAVA, potential ventilation corridors across Shenzhen are then created using the least cost path method. Subsequently, the optimized ventilation corridors are generated via super-imposition over a satellite image and the identification of functioning and compensating areas. Notably, the IAVA introduces the effects of terrain, vegetation, and open space, thus providing a more pragmatic evaluation of the wind environment than frontal area density results. Furthermore, it provides planning guidance for local governments that considers the quality of the urban wind environment in the low-cost and efficient construction of ecological and livable cities.