Harbin Street Environment Optimization Research Based On Spread Of PM2.5 During Heating Period

Nowadays, under the deepening development of urban industrialization and the massive burning of the fossil fuels, the mass concentration of the suspended particle pollution tends to exceed standard and the fog and haze weather appears to be on a regular basis, leading to the deterioration of the urban microclimate. As a typical high-latitude winter city, Harbin has a long cold winter with a sparse vegetation, and the heating during this period will lead to a lot of PM2.5 emitting in the air. This thesis attempts to interpret the factors that influence environmental issues from the perspective of the building layout and street network, to include the air pollution spread into a special research issue of urban planning, and to propose the microclimate compensation planning measures, in order to make the city more environmentally, scientifically and organically friendly. The focus of this study is on the increasing of the urban PM2.5 spread, the object of this study is the spatial correlation properties of the Harbin City streets and their geometrical parameters, and the goal of this study is to reduce the suspended particles pollution in cold area city during the heating period by using the urban planning method.In this paper, considering the background of the high-latitude cold area city and its complex microclimate conditions, we monitored the on-site environmental data during the heating period and studied an ideal model with computational fluid dynamics(CFD) numerical simulation, carrying out a number of streets analysis and comparative research of the spatial geometric elements. Firstly, we carried out some basic researches about the PM2.5 dispersion characteristics, the impact of city streets to the spread of PM2.5 and the microclimate compensation factor impacts. Secondly, we also proposed an optimization strategy on reducing the PM2.5 mass concentration by using CFD technology on comparing with different urban street network, geometric parameters street space, street planes, street intersections and their relationship with the ventilation of the city. Finally, the numerical simulation results were verified by the on-site data monitoring study of Central Avenue in Harbin sector, resulting in the development of the site-specific microclimate compensatory measures plan, dividing the street into areas that suitable for activity, that need fast access and that need microclimate compensatory.From the perspective of PM2.5 diffusions, this thesis studies the urban street space in order to form a constructive guidance, to optimize the spatial layout of the new district, and to provide a favorable basis for the arrangement of green water and other microclimate compensatory measures. This study contributes to the overall improvement of urban living environment and the sustainable development of a health and environmental protection city.