Breathing city

Abstract

In recent years, with the deepening of the urbanization process, high-density urban development models have led to a series of climatic problems such as poor urban ventilation and air pollution. Urban morphology forms a unique microclimate in the city, which has an important impact on the diffusion and distribution of pollutants inside the urban boundary layer. Chengdu, as a large central city in the southwestern of China, has developed rapidly, with numerous sources of atmospheric pollution. At the same time, its basin topography and climatic conditions make it difficult to dilute and disperse pollutants. In this thesis, the background of Chengdu was introduced, and the severe trend of urban development and air pollution was stated at first. Secondly, further understanding of the relationship between urban morphology, urban microclimate and air pollution will be involved. And a city-scale risk assessment was conducted to define the most vulnerable areas. Thereafter, it is possible to evaluate the microclimates represented by the wind and heat environment in these areas. Then integrating pollution abatement and microclimate design into the urban design process by using a maximization approach. From the aspects of street canyon morphology, surfaces and urban trees, proposing wind-heat coupled optimization solutions to reduce air pollution. The guidelines and design method are aimed at improving the scientificity of urban design and providing a reference for the creation of sustainable and healthy cities.