居住街区街道空间友好性评价研究——基于居民主观测度视角

Research on the Evaluation of Street Space Friendliness in Residential Blocks:A Case Study Based on the Subjective Observation of Respondents

居住街区街道作为数量最多、居民日常使用最频繁的空间类型,其步行友好性的提升具有完善街道低碳交通功能和增强其社交属性的双重内涵。以南京河西地区居住街区街道为研究对象,调研步行者对街道空间环境的主观感知与街道的客体环境指标,提取共性评价因子,获取步行者对街道的心理评价结构为社交、空间氛围、绿植和设施四项主成分因子。在街道各项评分的基础上,对街道主观评价与客体指标作相关性分析,解析街道客体指标对居民心理感知的影响机理:界面通透系数、商业互动界面占比和服务设施数量影响社交感知;街道宽度、街道高宽比、居住区出入口密度、节点公共广场密度及灌乔木覆盖比等影响空间氛围的感知;街道宽度、边界绿化密度、隔离绿化密度及乔木遮荫率影响绿植感知;服务设施数量和商业互动界面占比会影响设施使用便利性感知。之后针对性提出利于步行友好的居住街区街道空间环境指标建议。

Residential streets refer to urban roads that divide each residential block(community)within the residential area.As the most frequently used space carrier for daily commute travel,leisure travel,and various living activities,residential streets serve for the travel and transportation function and create a community communication space with social attributes for residents.Based on the subjective observation of residents,it is of great theoretical and practical significance to explore the relationship between street space environments and walking behaviour in residential blocks for constructing an evaluation system of the walking environment and building a walking-friendly city.In this study,a questionnaire survey on pedestrians’psychological feelings and emotions in 20 residential streets in the Hexi district of Nanjing City was carried out using the semantic differential(SD)method.Data of built street environments were collected,comprised of drawings and measurements.On this basis,the common factors in the SD evaluation were extracted by factor analysis.Four principal component factors of the pedestrian’s psychological evaluation structure of street were recognised,including social interaction,spatial atmosphere,vegetation and facilities.Additionally,scores of the evaluation items of each street based on common factors were acquired.A mathematical model was established with these scores to analyse correlations between built environmental indexes(e.g.,spatial scale,boundary space,functional facilities and street greening)and subjective observations of residents,recognise street space environmental elements that influence subjective perception significantly and analyse influencing the mechanisms of objective street indexes on the psychological perception of residents.Specifically,the interface permeability coefficient,proportion of commercial interactive interface and number of service facilities influence social perception.The street width,street aspect ratio,density of residential entrances and exits,density of the public square and shrub coverage ratio affect the perception of the spatial atmosphere.Street width,greening density at borders,isolation greening density and shade rate of trees affect the perception of vegetation.The number of service facilities and the proportion of commercial interactive interfaces affects facility convenience perception.Based on the built environment data and correlation analysis results,the walkability of residential streets can be improved by optimising the service facility configuration,interface design and the sense of the spatial envelope to improve the friendliness of the street envelope interface.The interface permeability coefficient,the proportion of commercial interactive interfaces,and the number of service facilities can improve the pedestrian’s perception of the social atmosphere and street vitality.According to the subjective observation values,the non-negative evaluation in the perception of street social vitality can be achieved when the interface permeability coefficient reaches 0.5,and the proportion of commercial interactive interface reaches 0.22.The positive evaluation of pedestrians in the space perception of the street when the street aspect ratio is 0.9 is better than that at 1.5.We can optimise the street section and boundary space design to provide enough effective width for the sidewalk and improve the densities of isolation greening and shrub planting.When the street is about 40 m wide and width is about 40 m,and the effective width of the sidewalk is over 1.7 m,pedestrians will have a positive emotional perception of the street spatial atmosphere.Compared with the street width of 24 m in Longjiang district,pedestrians give a higher evaluation to 40 m wide streets.This is different from the previous cognition and shows the particular importance of the street’s section size and boundary space design.It is beneficial to enhance the perception of the street atmosphere by paying attention to the planting density of isolation and boundary greening in streets and increasing the proportion of shrub planting.We can strengthen the behavioural guidance design of the residential entrance space and public space at street nodes,avoid interference of vehicle traffic to pedestrian space,and provide diversified activity venues.A negative perception occurs upon the excessive density of residential entrances and exits and excessive density of bicycle parking areas along the street.In contrast,the perception of the spatial atmosphere can be improved by increasing the density of node public squares.There may be some deviation in the data analysis results due to the restrictions by the interview questionnaire and the number of sample streets.This needs further improvement.In addition,there was a small greening difference between the sample residential streets due to the excellent greening planting in Nanjing and high overall greening coverage in the built-up area.In research and sample selection in the future,it is suggested to strengthen the variability of street characteristics and make the differential representation of tree coverage and green vision rate more obvious to further clarify the impact of vegetation on the psychological perception of residents.