Study On Urban Ventilation Effect And Its Impact On Surface Temperature Under Different Climate Backgrounds In Chinese Cities

With the acceleration of urbanization,urban form changes have seriously affected the natural adjustment process of surface temperature,and the problems of rising temperature,air pollution and energy consumption have become increasingly serious.With urban structure planning,it is the best to solve urban problems by making full use of natural conditions.The solution can alleviate the pressure brought by the tightening of natural resources to some extent.Quantitative assessment of current urban natural ventilation conditions and analysis of its role in mitigating urban thermal environments is particularly important for improving ventilation environments through urban planning to solve urban problems.There are 31 capital cities and municipalities directly under the Central Government of China's capital cities and autonomous regions.There are five types of cities that span five climatic zones.Therefore,this paper selects 31 cities as research areas,based on building vector data,meteorological data and remote sensing image data.The authors,GIS software analysis,function drawing software drawing,etc.analyze the natural ventilation effect of the city,classify the urban natural ventilation effect gradient grade,and analyze the influence of urban natural ventilation on the surface temperature in winter and summer during different weather backgrounds..The main conclusions are as follows:(1)Among the super-large cities,Shanghai has the best natural ventilation effect;Beijing and Tianjin have low natural ventilation effects;Chongqing has the worst natural ventilation,and is the worst city in the provincial capital cities..Among the large cities,the natural ventilation effect is suitable for Chengdu,Nanjing and Shenyang.Wuhan and Guangzhou have natural ventilation effects,Xi'an,Harbin and Hangzhou have low natural ventilation performance,and Hangzhou has the worst natural ventilation effects.In large cities,the natural ventilation effect of the type-II city is significantly worse than that of the type-I;in the type-I large cities,the ventilation effect is ranked as Changsha>Nanning>Zhengzhou>Changchun>Jinan>Shijiazhuang>Nanchang;the ventilation effect of the type-II large cities is ranked in Urumqi >Taiyuan>Lanzhou>Guiyang>Xining>Haikou>Hohhot>Hefei>Yinchuan>Fuzhou>K unming.The type-I small city of Lhasa has the best natural ventilation effect in all research cities.(2)The natural ventilation effect of the provincial capital cities is divided into six levels and six gradients.The first gradient in the appropriate level has good natural ventilation effect.There are 5 cities: Lhasa,Changsha,Urumqi,Chengdu,and Nanning;the second gradient has good natural ventilation effect,and there are 5 cities: Taiyuan,Shanghai,Lanzhou,Zhengzhou and Nanjing;The third gradient natural ventilation effect is basically suitable,there are 4 cities: Guiyang,Shenyang,Changchun,Xining.In the general level,the fourth gradient natural ventilation effect is general,there are 4 cities: Jinan,Wuhan,Guangzhou,Shijiazhuang;the fifth gradient has natural ventilation effect,there are 6 cities: Xi'an,Harbin,Beijing,Harbin,Hangzhou,Tianjin,Haikou.The sixth gradient in the poor level has poor natural ventilation.There are 7 cities: Hohhot,Hefei,Yinchuan,Fuzhou,Nanchang,Chongqing and Kunming.(3)Under the temperate monsoon climate,the surface temperature is most affected by natural ventilation,and the effect of night ventilation on surface temperature is significantly stronger than that during the day;the effect of natural ventilation on surface temperature is second in subtropical monsoon climate;temperate continental climate,tropical Under the background of monsoon climate and plateau mountain climate,the nighttime surface temperature is more affected by ventilation than during the daytime.In the temperate continental climate,the effect of nighttime natural ventilation is significantly higher in the summer and winter than in the daytime.