Refined Planning Of Beijing Ventilation Corridor Based On Big Data Identification And CFD Technology

With the comprehensive construction of the new data-driven "Smart Beijing",the research on the urban human settlement environment of Beijing increasingly relies on the mining and analysis of big data,especially in the field of urban macro-climate environment analysis and research,the collection and application of urban meteorological big data has become an important research basis.For the refined planning and construction of Beijing’s urban ventilation corridors to alleviate the"pain points" of Beijing’s climate,the application of big data processing identification and decision-making will provide a new research idea for the governance of Beijing’s regional climate and environment and the further refined planning and construction of urban ventilation corridors.Firstly,this paper studies the theory of urban ventilation corridor,and summarizes the relevant research situation at home and abroad,including the development context of urban ventilation corridor theory,big data research related to urban spatial planning,various methods of climate simulation research,as well as the basic application of CFD in climate research.On the basis of clarifying the influencing factors of urban wind environment,this paper summarized and analyzed the characteristics of urban air duct of different types of urban wind environment(river type,green space type and road type),the functional space(action space,compensation space and air guide channel)and the action mechanism of urban air duct system.Based on the above theoretical research,the urban ventilation corridor research and planning process(relevant database establishment,data processing,ArcGIS identification,CFD simulation and verification of unit plots)were established in this paper.Secondly,on the basis of clarifying the theory of urban air duct system and its construction process,multi-dimensional related factors are constructed,and the urban air duct construction method combining quantitative analysis and qualitative analysisis adopted to conduct data analysis and identify and plan various functions.To be specific,the research proposes to use three functional parts,namely function space,compensation space and air guide channel,to determine the big data of relevant factors of each functional space of ventilation corridor based on the city,and make scientific decisions on all kinds of data.In terms of data and space connection,land surface temperature was retrieved from Landsat-8 data from 2013 to 2019 based on ENVI tool.With Tableau visualization tool,the meteorological data of automatic meteorological stations accumulated for 4 years will be analyzed and wind rose chart and wind frequency chart will be drawn to summarize and analyze the dominant wind direction,wind direction characteristics in each season and each month.The PM2.5 monitoring data characteristics of 34 automatic weather stations and the annual TSP data characteristics were used to determine the urban action space and compensation space,air guide channels and the characteristics of urban wind direction in different seasons,comprehensively analyze and determine the potential urban air duct,and put forward the construction methods of the potential air duct.Finally,based on ArcGIS classification assignment and superimposed analysis technology,the city center is divided into several 1000 m*1000 m unit module,the data were drawn city downtown area to each single factor assessment unit block diagram,and on the basis of evaluation index to determine the function space,compensation space,ventilation potential comprehensive impact factor assessment unit block diagram.On this basis,the ventilation potential of the identified plots was evaluated and verified.Through CFD simulation,the wind environment conditions of the plots with good ventilation potential and the "obstruction points" with poor ventilation conditions under the prevailing wind direction in winter and summer were analyzed.Meanwhile,the control measures that could be adjusted at the macro and micro levels were summarized.In this paper,the urban air corridor study process,established the related database and visualization analysis result,the evaluation index,the function of ventilated corridor space and urban scale with 1000 m*1000 m unit plot research method is improved and unified data overlay analysis of operational degree greatly to resolve the macro level the difficulty of the city gallery ventilation simulation,both the ventilated corridor on macro and micro scale research.