Simulation Study On The Influence Of Greening Structure On The Wind Environment Of The Existing Multi-storey Residential Districts In Harbin

As one of the important means of optimizing the urban physical environment,green space has received extensive attention in the planning of urban green space system and the study of how to improve the ecological benefits of the landscape.Residential areas are an important part of the urban built environment,and the wind environment,which is one of the physical environment elements,has a greater impact on the micro-environment comfort of local areas of the city.In recent years,the issue of renewal of existing settlements has become the focus of the renovation of settlements.This paper selects the green space between houses in a multi-story residential area as the research object.By extracting the layout patterns of typical buildings and green spaces in the residential area,the model is established using ENVI-met as a simulation platform.Based on the results of numerical simulations,the wind conditions under different greening structures are analyzed.The environment is comparatively analyzed.The contents included are the investigation of green space layout,the extraction of typical green space layout patterns,the design of variable simulation schemes,the setting of simulation parameters,and the data sorting of simulation results.The main work and research conclusions are as follows:(1)Through literature reading and data sorting,summarize the relevant research results from three aspects:the influence of plants on the wind environment,the influence of greening on the wind environment,and the influence factors of greening on the wind environment.(2)The computer numerical simulation technology is introduced,and the basic theories such as the characteristics,scope of application,advantages and disadvantages of commonly used simulation software are explained.It also explains in detail the main features of ENVI-met,grid construction,simulation parameter settings,etc.(3)Analyze the multi-layer determinant layout of residential areas in Harbin through satellite maps and field surveys,and extract the typical multi-level determinant residential building patterns and typical green space layout patterns that are in line with the actual situation in conjunction with relevant design specifications.On this basis,four simplified basic planting forms are listed as a set of variables in the quantitative simulation experiment.In addition,the planting ratio of trees and shrubs is set to 1:2,1:1,2:1,and the height of shrubs is 1m.Two sets of variables of 1.5m and the height of the branch point of 2m and 4m are used to build a simulation platform using ENVI-met three-dimensional microclimate simulation software.(4)Compare and analyze the impact of different elements on the outdoor wind environment of the residential area based on the simulation results.Simulation data analysis shows that the different forms of green planting will lead to different wind-proof and wind-guiding effects,and the location of trees has a greater influence on the distribution of wind speed.When the planting ratio of trees and shrubs changes,when the proportion of trees increases,the wind-proof and wind-conducting functions of the green space show an overall upward trend,but they are slightly different when planted according to different green planting forms.The simulation of the influence variables of the green height on the wind environment found that the lower the height of the tree branch point and the higher the height of the shrub,the stronger the ability of the green space to reduce the wind speed at the pedestrian height,but the height of the tree branch point is too low or the height of the shrub is too high.High will cause no ventilation.The results of the study showed that:the planting pattern,the planting ratio of trees and shrubs,the height of shrubs,and the height of branches of trees will all affect the distribution of outdoor wind speed in residential areas.Unreasonable greening structure will not only not improve the wind environment,but will also produce unventilated phenomena or aggravate the gorge effect.Therefore,reasonable green planting is essential in the planning and design of residential green spaces.