Research On The Restorative Effect Of Street Environment Based On Multi-source Data

With the increasingly prominent problem of urban public health,the construction of healthy cities has become a global issue.Paying attention to the needs of residents for the healthy quality of urban space environment has become a particularly important part of the field of public health.As the public living space most closely related to residents’ daily life,the restorative potential of urban streets in reducing mental stress and promoting healthy behaviors has gradually attracted the attention of scholars in the industry in recent years.This paper takes the street space in the old city of Nanjing as the research object,and constructs a restoration street measurement and evaluation framework based on the physiological orientation of street life needs and the psychological orientation of street experience needs,including three levels,namely the total dimension(street environment restoration)-4 measurement evaluation criteria(street restoration needs)-12 measurement evaluation index factors(street environment element characteristics),of which the evaluation criteria include 4 levels of patency,stability,service and comfort.Using methods such as big data quantitative measurement combined with machine learning technology,eye tracking technology and restorative perception scale,etc.,the restorative potential characteristics,the impact mechanism and magnitude of restorative elements in the streets of the old city were explored,and finally the macroscopic and microscopic aspects were analyzed respectively.The optimization strategy is proposed at the level.The results of the study are as follows:(1)The characteristics of the restoration potential of streets in different dimensions of the old city are different:(1)The overall patency is poor,the degree of connectivity(average 2.63),the choice of 300-meter walking distance(average 12.70),and the proportion of pedestrian space(average 12.6%)overall are lower;in terms of spatial structure,it shows the structural characteristics of circles and radials.(2)The coverage and richness of service functions are relatively high as a whole,with high measurement values in multiple regions;in terms of spatial structure,it shows the distribution characteristics of large clusters and small dispersions,and the structure expansion is insufficient.(3)The biggest influence on comfort is the high degree of interface closure(average 28.8%),the overall green viewing rate is relatively high(average31.5%),followed by sky openness(average 30.4%);in terms of spatial structure,the overall results show "Inside low outside high" trend.(4)Non-motorized traffic(average value 5.4%)has the greatest impact on stability,followed by motorized traffic(average value 1.0%),and pedestrian congestion is not high(average value 0.5%).(2)The restorative influence factors of different types of streets are different,and the influence directions of the factors are also different.The restoration design of the street environment needs to comprehensively consider different functional characteristics and multidimensional factors.Overall,the streetscape elements that can most promote restoration are landscape facilities(0.049),followed by tree canopies(0.048);the streetscape elements that inhibit restoration are: cars(-0.087)> tree trunks(-0.082)> bus stop signs(-0.048)> building(-0.044)> non-motorized vehicle(-0.037).(3)The influence intensity and magnitude of the streetscape elements on the four environmental characteristic factors are obtained.(1)The characteristics that affect the patency are mainly manifested in two aspects: the effective width of the pedestrian space and the accessibility of walking.When the proportion of pedestrian space is 25%-30%,the recovery benefit is high,and the width of the one-way pedestrian area should be guaranteed to be 1/8-1/5 of the width of the road;setting up open spaces such as squares or green spaces along the street can significantly increase the recovery.sexual benefit.Steps along the street will inhibit recovery,and the pedestrian space should be designed to be barrier-free to ensure coherence and smoothness.(2)The characteristics that affect the stability are mainly manifested in two aspects: road division and traffic elements.The impact of non-motorized traffic on pedestrians is higher than that of motorized traffic.When pedestrians,non-shared boards,and the width of non-motorized vehicle lanes are higher than sidewalks,the recovery will be significantly inhibited.Therefore,attention should be paid to the separation of pedestrians and vehicles and the rational allocation of road space resources.The pedestrian flow on the pedestrian path should also be reasonably controlled,and the number of pedestrians within the line of sight of pedestrians on a 3m-wide sidewalk should be 3-5.(3)The characteristics that affect comfort prominently represent the spatial visual permeability,which are reflected in three aspects: green viewing elements and green viewing rate,field of view sky openness and interface transparency.The increase of the green vision rate will improve the restorative benefit.The appropriate value range is between 28% and 55%.When the green vision rate is 44%,the restorative effect is the best.The road tree species with large crowns and thin trunks have better restorative benefits.it is good.The setting of landscape facilities such as flower boxes will promote recovery,but it should not be placed when the width of the sidewalk is less than 2.5m.The openness of the sky in the field of view should be between5% and 10%.In more congested road sections,the increase in the openness of the sky will compensate for the restorative benefits.The main factors affecting the openness of the sky are construction and other artificial elements,the height of buildings along the street and the setback distance should be controlled.The wall will inhibit the recovery,minimize the use of the solid wall interface,and can be used for wall decoration when necessary.(4)The characteristics that affect serviceability are mainly manifested in two aspects:facility type,building proportion and type.Public toilets in public facilities will promote recovery,and should be added reasonably in the streets;signs in infrastructure have a promoting effect,and distribution boxes have a restraining effect;traffic facilities will promote recovery in streets with high traffic flow,but in Scenic streets have an inhibitory effect,in which street lights can promote the perception of environmental harmony,and traffic signs can significantly improve resilience in congested streets.The proportion of building elements should be between10% and 35%.Different building types have different effects on restoration.Commercial buildings have a promoting effect on roads with higher grades,while science,education and cultural buildings and residential buildings have an inhibitory effect.effect.(4)According to the research results,from the four dimensions of patency,stability,service and comfort,summarize the problems of the streets in the study area,and then put forward the renovation strategies respectively.In addition,based on the impact mechanism of street environment restoration,two streets with different grades and types of functions are taken as examples to carry out specific optimization and reconstruction.This study embodies the people-oriented care concept and responds to the development strategy of healthy cities.The research results provide new research ideas and optimization design references for healthy restoration-oriented urban streets.