Analysis On The Evolution Of Wind Environment At Pedestrian Height Based On Urbanization Development

In the process of urbanization,along with the evolution of urban architectural landscape,the microclimate of the city has changed significantly,and the problem of urban atmospheric environment has become increasingly prominent.It is important to study the temporal and spatial distribution characteristics of the wind environment during the evolution of urban architectural landscapes and explore the impact of architectural landscape evolution on the wind environment,which will provide important guidance to the rational planning of architectural layout and design of future cities.Based on the 3D basic data of buildings in the years of 2003,2006,2009,2012 and 2018,the paper chose average building height,building density,floor area ratio,void ratio,height standard deviation,building height density,building height types and other indicators,based on spatial analysis method by Arc GIS,to study the temporal and spatial evolution of the architectural landscape of the Shibei District and the Central Business District from 2003 to2018 firstly.Then numerical simulation technology was used to simulate the wind environment in Shibei District and the Central Business District.The average wind speed,wind speed area ratio,wind speed dispersion and other indicators were selected to analyze the temporal and spatial distribution characteristics of the wind environment in the study area,At last,combining correlation analysis and regression analysis,this paper explored the impact of the architectural landscape evolution on the wind environment of Shibei District and the Central Business District.The results showed that from 2003 to 2018,the area and number of low-rise and multilayer buildings decreased in Shibei District and the Central Business District,and the area of medium-high-level,high-rise and skyscraper increased.The construction land in Shibei District and the Central Business District has been reduced,the building capacity has increased,and the architectural landscape has shown a three-dimensional development trend.From 2003 to 2018,the average wind speed and the area ratio of the comfort zone in Shibei District gradually decreased at the pedestrian height,the area ratio of the quiet wind zone and the area ratio of the strong wind zone gradually increased,and the quality of the wind environment declined in winter at the pedestrian height.In summer,the average wind speed and the area ratio of the comfort zone first decreased and then increased.The area ratio of the quiet wind zone and the area ratio of the strong wind zone first increased and then decreased.The quality of the wind environment first decreased and then improved.During the study period,the average wind speed in the Central Business District is increasing first and then decreasing at the pedestrian height.The wind speed dispersion in the Central Business District has a trend of decreasing first and then increasing.In general,The ventilation effect of the study area increased first and then decreased over time,and the quality of the wind environment first increased and then decreased at the pedestrian height.Based on analyzing the impact of architectural landscape evolution on the wind environment in two scales,it can be concluded that the average wind speed and the area ratio of the comfort zone at the pedestrian height of Shibei District are negatively correlated with the average building height,building density and floor area ratio.the area ratio of the quiet wind area at the pedestrian height It is positively correlated with the average building height,building density and floor area ratio.the area ratio of strong wind area at pedestrian height is positively correlated with the average building height and floor area ratio.The average wind speed at the pedestrian height in the Central Business District is negatively correlated with building density,floor area ratio,and building height density,and positively correlated with void ratio.Wind speed dispersion at the pedestrian height in the Central Business District is positively correlated with building density,floor area ratio,height standard deviation,building height density,and building height difference.Based on the correlation and regression analysis of the two scale building landscape indicators and wind environment indicators at the pedestrian height,the wind environment optimization strategies are proposed respectively: the urban wind environment quality can be improved by controlling the building density,adjusting the floor area ratio,and constructing ventilation corridors in Shibei District,The wind environment of the block can be improved by controlling the layout of the building and adjusting the type of building height change in the Central Business District.