Study Of The Interrelationship Between Urban Texture And Aerodynamic Roughness

Because of the change of urban morphology, the environments in which we live are changing. In China, air pollution is an increasing concern among these environmental issues. The key element in the study of air quality is the urban morphology and the resulting changes in urban wind conditions. The relationship between urban wind and the drag force on buildings can be characterized by the aerodynamic roughness. The increase of the value of roughness also raises the intensity of the turbulence, which directly influences the dispersion of pollutants. The greater the range of dispersion, the lower the concentration of pollution in the atmosphere. Based on these, this paper focused on the interrelationship between urban texture of Nanjing and the aerodynamic roughness with the help of computer. Some basic findings were presented in order to provide quantitative indexes for urban design and research, so as to purify the urban microclimate.The content of this paper is divided into six chapters. A brief introduction to the background, purposes and significances of the study were presented in chapter one. Chapter two reviewed most kinds of algorithm of calculating aerodynamic roughness, as well as the development of the study between urban morphology and aerodynamic roughness. Chapter three introduced the method using Rhino-Grasshopper as the platform for calculating aerodynamic roughness. Some valid case study sites were picked up to limit the scope of this study in chapter four. And chapter five is the most important part of all, since it presented the interrelationship between the aerodynamic roughness and urban texture on six sections:building height, plan area ratio, floor area ratio, frontal area ratio, building shape coefficient, building dispersion ratio. The last chapter summarizes the basic principle of the findings on the basis of the study above and gives prospect of the later work.