Abstract
Nowadays, rapid urbanization and the massive consumption of natural resources have led to a series of urban problems, such as the urban heat island effect, global warming and urban pollution aggravation. These problems make high-density cities or countries begin to reflect on how to better use natural resources instead of artificial systems to create a comfortable urban living environment for people in the future to achieve carbon neutrality and sustainability. This study takes Singapore as an example. Singapore is one of the highest densities among mega‐cities in the world. Tall and bulky high‐rise building blocks with very limited open spaces in between and large podium structures have led to lower permeability for urban air ventilation at the pedestrian level. In Singapore’s hot and humid summer weather conditions, the air conditioner uses a lot of electric energy to bring the indoor hot air to the outdoors through the circulation system, which further leads to the deterioration of the city's outdoor climate thermal comfort. Therefore, how to improve urban microclimates to reduce the use of air-conditioning systems to alleviate the heat island effect and eliminate air pollutants is an important issue that most cities are facing at the present stage of development. This study has been conducted to examine the effects of urban and architecture morphology and density in the south area of Singapore on the pedestrian level urban wind flow. In order to provide the detailed information of urban permeability distribution, the meteorological information and 3D urban morphology data were simplified and integrated into the geographic information system (GIS) by comprehensively considering the influencing factors of monsoon, topography (hill and valley), sea and land, etc. The simulation results show that independent patches can be formed in high-density areas of the city, and potential wind channels can be formed in low-density areas between the patches. Since these wind channels have different directions, different wind paths will be formed for different seasons and time periods. Through the analysis of these air path, it is found that in the area of potential air paths, there are still some buildings with high coverage rate that hinder the formation of air paths. Therefore, solving these "problem buildings" to open air paths is the focus of urban air path planning. Architectural design methods such as increasing the porosity of the building and reducing the area on the windward side of the building are adopted to renovate and redesign these "problem buildings". The wind environment of each new design plan is simulated through CFD software, and then urban air paths will be established to improve the urban wind environment, so as to achieve the goal of urban carbon neutrality and sustainability.
