Research On Optimization Strategy Of Green Space In Beijing Ventilated Corridor Based On Geography Design

Urban heat island effect and air pollution have brought a series of ecological environment problems to urban built-up areas and caused serious harm to residents’ living,consumption and physical and mental health.As an important spatial control means to alleviate urban climate problems such as urban heat island effect and improve residents’ health,urban ventilation corridors are included in land planning and urban green space system planning.The analysis and planning of urban ventilation corridors based on geographical design methodology has become a hotspot in landscape architecture,landscape design,urban and rural planning and meteorology.Ventilated corridor planning and control is focused on the study of block orientation and building layout.Based on landscape garden view,this study aims at relieving urban heat island effect,carries out the study of ventilation corridor planning and the green space optimization strategy of wind tunnel scenic spot,aiming at scientific and rational demarcation of ventilation corridor,and provides reference for promoting the combination of ventilation corridor and landscape to improve the ecological efficiency of urban green space system.In this study,a geographical design model was established to analyze and evaluate the ventilation potential factors of the six inner rings of Beijing,including topography,thermal environment,construction environment,urban green space,road network,water body and cold source level.The spatial distribution of ventilation potential in the six inner rings of Beijing was constructed,and the location of the potential wind tunnel was excavated by using LCP method in ArcGIS based on surface roughness.This paper discusses the characteristics of summer temperature field distribution and the spatial distribution pattern of heat field in the six rings of beijing,superimposes the distribution of ventilation corridor with the distribution of heat island and the distribution of green area and water body,combines the cooling effect of the potential cooling factor of current situation(green area and water body),puts forward the optimal layout of green area node and ventilation green corridor at the level of green area system.According to the grade of ventilation corridor,three kinds of ventilation corridor landscape are divided into different levels,the optimization schemes of important nodes of ventilation corridor landscape are listed,and the optimization strategy of ventilation corridor green space based on green space system is put forward.The main conclusions of this study are as follows:(1)The analysis of the current situation of ventilation potential in the six rings of Beijing shows that the areas with high ventilation potential are located in cold source areas such as rivers,woodlands and farmland on the outskirts of the outer ring.Medium ventilation potential area is large,mostly near high ventilation potential area,as well as open space such as non-construction land,main roads,concentrated green space and plaza in near suburbs.The low-ventilation potential area is mainly located in the central part of the city,especially in the core area,but there are some well-ventilated open spaces such as park green space,river water system and large plaza.(2)The spatial pattern of temperature field in Beijing Six Rings shows that the medium temperature zone is more than 70.54%;the temperature between the five rings and the sixth ring is relatively low,about 27℃-31℃;urban center under lower pad There are a lot of temperatures in the suburbs,and there are many high temperature aggregation areas in the urban construction zone.There is a local high temperature area in the southern and second rhindies;high temperature zones are near the industrial park,indicating the formation and strength of urban heat island.Urban layout features and functions are related.The temperature around the water in the urban area is approximately 26℃ to 28℃,the water in the heart of Shicha Sea,the vegetation,and the park is low,the water is visible,and the green space can effectively reduce the temperature of the surrounding land and soothe the city’s hot island.The city’s heat island effect is closely related to urban land,water,woodland,farmland,and grassland in low temperature zone and subtemperature zone,barely and towns at high temperature zones and strong high temperature zones,and surface temperature is low to high alignment for water.Farmland <Farming <Naked ".(3)The spatial pattern of urban heat island in Beijing’s Inner Six Rings in 1984,1999,2010 and 2017 shows that the heat island effect is increasing in Beijing’s Inner Six Rings region.With the urbanization process,the heat island expansion is characterized by a phasing-in trend,with the intensity of heat island increasing from 3 to 5.The Qianghe Island block is concentrated in the central city,Changping district in the northwest and along the six western rings.Almost 80% of the study area was covered by heat island.The intensity of heat island in the central area was significantly higher than that in the peripheral area,especially in the core area.(4)Based on the structure of green space system and the current cooling pattern of river green space in the six rings of Beijing,five primary ventilation corridors and nine secondary ventilation corridors were selected by superimposing potential wind channels,heat field spatial patterns and land use types,and 12 cold source areas were identified.Corridors are large in scale and often pass through open spaces such as channels with low roughness,green spaces and roads that conform to prevailing summer winds.The layout shows four outer suburbs with fewer inner core areas,more east and less west,and uneven spatial distribution.According to the urban ventilation corridor level,there are 19 primary modified greenspace nodes,11 secondary modified greenspace nodes,and 12 additional greenspace nodes.