A Study On The Pedestrian Suitability Of Urban Street Landscape

As an important part of the urban public space,streets are the main carrier of pedestrian behaviour.However,the expansion of the city and the population’s agglomeration effect have led to land constraints and the intensification of the traffic function of the street,which has restricted the walkability of the street in many ways.Given the limited space available in cities,the composition of the streetscape is an important factor in enhancing the pedestrian experience and promoting the suitability of streets for walking.The study uses streetscape data and semantic segmentation technology to obtain basic streetscape data and explore the evaluation of pedestrian suitability of urban streets based on visual landscape,as well as the optimisation strategy of pedestrian suitability by analysing the landscape characteristics of typical streets and extracting typical observation points as the pedestrian suitability of streetscape.The study provides a reference basis for the improvement of the walkability of the street landscape.The main conclusions of the study are:(1)Pedestrians’ visual perception of the street landscape is an important connotation affecting walkability.The study deconstructs the street landscape from the perspective of the street space interface,and based on the theory of visual perception of the landscape,it comprehensively determines the green view rate,sky visibility index,shade rate of the walking space,walking safety and landscape colour richness as the evaluation indexes of the walkability of the street landscape,and uses the principal component analysis method to The weights of each index were determined by using the principal component analysis method,which were green view rate(0.2372),sky visibility index(0.2874),colour richness(0.1416),walking safety(0.1820)and shade rate(0.1518).(2)Street observation points were set at 100 m intervals,and street images were crawled in four directions horizontally,4472 observation points and 17888 street images were obtained.The images were classified and processed using FCN semantic segmentation,and the corresponding indicators were obtained by combining the influence of walkability connotations.The observation points with high green visibility are mainly located around parks and mountains,and those with high green visibility and high ranking account for 50.90% of the total number of observation points,and the overall green visibility of streets in the study area is high.The sky visibility index spatially shows a characteristic of "low in the middle and high in the surrounding area",with 50.20% of the total number of observation points having a high sky visibility index and a high rating,and the overall sky visibility index of streets in the study area is low.The distribution of colour richness is characterised by "high values across the board and a few low values",with 37.72% of the total number of observation points with high colour richness,and the overall high colour richness of streets in the study area.The high values of pedestrian safety are concentrated in the central axis of the study area,and the highest percentage of moderate pedestrian safety is 49.69%,the overall pedestrian safety of the streets in the study area is average.The high values of shade rate are concentrated within the Second Ring Expressway,while the low values are concentrated in the upper reaches of the Minjiang River and around Gao Gai Mountain.58.25% of the total number of observation points have low and high shade rates,and the overall shade rate of streets in the study area is polarised.(3)Using the weighted superposition analysis of GIS to obtain the comprehensive evaluation results of urban street landscape walkability,the lowest value of comprehensive evaluation of landscape walkability was1.61,and the highest value of comprehensive evaluation of landscape walkability was 4.45.Using the natural breakpoint method,the comprehensive evaluation results were graded into five grades: one,two,three,four and five.The number of Level 3 observations was the largest,accounting for 31.25% of the total number of observations,while the number of Level 5 observations was the smallest,accounting for 6.75% of the total number of observations.Level 1 observations are mainly located in the centre of the study area and in the Jinshan district of Changshan District,and are clustered near urban green areas.The spatial distribution of Level 2 observation points is generally more even,with obvious clustering in Minjiang Avenue,South Riverside West Avenue and Riverside Central Avenue on both sides of the Minjiang River.The spatial distribution of the tertiary observation points is more even,with a strong continuity of distribution in the Jinshan area in the eastern part of Cangshan District and the urban core area in the southeastern part of Gulou District.Level 4 observation points are clustered in the secondary roads between the blocks in the central area and on the periphery of the study area.Level5 observation points are mainly clustered at the periphery of the study area,with a scattered distribution in the centre of the study area.(4)By extracting typical observation points of each level,the characteristics of the walkability of each level are analysed and optimisation strategies are proposed.The first level observation points are designed to enrich the colours of the street landscape and improve the service facilities to further enhance the walkability of the landscape.Level2 observation points focus on enhancing pedestrian safety by strengthening the boundaries of the pedestrian space and adding separation measures.Level 3 observation points should focus on the continuity of the landscape interface,ensure the permeability of the street space to improve the sky visibility index,and enrich the colour of the plant landscape to improve the colour richness.Level 4 observation points should increase the perception of greenery through differential greening and the use of tree canopies to supplement street shade,while strengthening the boundaries of pedestrian space to improve pedestrian safety.Level 5 observation points should focus on increasing the amount of greenery in the streets,using tree canopies to supplement street shade,planning the layout of pedestrian space and safeguarding pedestrian rights of way.Based on the optimisation and enhancement strategies of each level,specific optimisation measures are proposed in conjunction with specific typical observation points.The first level observation point is Jianxin Zhong Road,for example,where the suitability of the street for walking is enhanced by enriching the colour of the street landscape and installing street furniture.The second level observation point is based on the observation point on Fuxing Road,which uses separation facilities to strengthen the boundary of the pedestrian space and improve pedestrian safety.The third level observation point is Hongwan North Road,for example,where the street trees are reasonably combed to ensure a permeable view of the street,and the colours of the landscape are increased to enhance the richness of the colours.The fourth level observation point is the Changle Middle Road observation point,for example,by planting more large trees in the ranks of street trees,using flower boxes and lawns to spatially divide the road space,increasing greenery to improve the shade rate and at the same time improve walking safety.The fifth level observation point is based on the Ye Xia Road observation point,which increases the amount of greenery visible to pedestrians by adding planting to the landscape,and improves pedestrian safety and protects pedestrians’ right of way by integrating the street bottom interface.