Landscape Reconstruction Strategy Of Old Residential Areas In Beijing Based On Microclimate Improvement

As an important part of urban green space system,residential green space landscape becomes an important part of "multiple ecological compensation mechanism".At the same time,it is also an important way to improve the living quality of old residential areas in the work of "urban renewal".Taking Shijingshan District as an example,this paper establishes the basic information database of 35 old residential areas in Shijingshan district,and divides the green space types of residential areas into three categories: open parallel,open enclosed and closed parallel according to the content of the database.The micro-climate data of18 measuring points in 6 typical residential areas were measured,and the micro-climate measurement database of typical old residential areas was established.After simulating and visualizing the microclimate spatial distribution of 6 typical old residential areas at12:00 noon with ENVI-MET software,the data change rules and microclimate spatial distribution are analyzed.In summer,building density,building layout and vegetation structure,and green space area have obvious effects on the microclimate of surrounding sites.Building height mainly affects solar radiation,building layout mainly affects air temperature and wind speed,and vegetation structure mainly affects air temperature,relative humidity and wind speed.During the winter construction layout form is the dominant factor of space thermal comfort,determinant and jewels around buildings of public space in winter day more covered with shadows,and matrix,east,south can in a short period of time to accept the illumination at noon time,building density and greenbelt area vegetation structure,smaller influence on thermal comfort experience.In view of the above conclusions,this paper proposes a landscape reconstruction strategy based on the improvement of microclimate and thermal comfort in the current old residential areas: expanding green space area and enriching vegetation structure are the basic ways to improve the thermal comfort of the site,among which tall trees have a significant impact on wind speed.In the open parallel green space,tall coniferous trees and multi-level evergreen shrubs should be planted on both sides of the wind passage to weaken the influence of cold wind in winter.Dense evergreen vegetation barrier should be built around the open and enclosed green space to regulate the strong turbulence around the high-rise dot matrix buildings.In the closed parallel green space,conifer trees should be planted on the opening side to protect against wind in winter,and micro air channels should be reserved in the middle of the green space to ensure ventilation and heat dissipation in summer.Landscape transformation strategy based on the above,this article selects bajiao village in the south of the four landscape renovation exhibit of micro green space,compared with micro climate and thermal comfort,found that this article proposed reform strategy as A whole can be in duty summer two season effectively adjust the space comfort,including during the summer area A and area C PET improvement effect best,maximum temperature for more than 15 ℃;Negative optimization occurs in zone B with temperature rise of about 3℃.In zone D,the green space inside the higher temperature area shrinks slightly,but the cool area also shrinks.In winter,the improvement effect is relatively insignificant,and the overall temperature rise is about2℃.The area of cold area in ACD three zones decreases slightly,while the area of cold area in B zone increases.