Research On Landscape Vitality Evaluation And Optimization Of Auxiliary Space Under Overpass In The Proper City Of Chongqing

As a typical mountainous city,Chongqing has solved the contradiction between mountainous environment and urban transportation construction through the extensive construction of overpasses in the context of rapid urban development.However,the resulting large number of ancillary spaces under bridges has also posed many new problems for urban development.As a part of urban public space,the lag in landscape construction of the space under the bridge cannot meet the improvement of urban residents’ requirements for public space quality and activity needs.This article discusses how to efficiently utilize the space under the bridge,improve the landscape quality of the space under the bridge,stimulate public space vitality,and promote healthy urban development and efficient resource utilization from the perspective of landscape vitality optimization.This article takes the affiliated spaces under overpasses in the main urban area of Chongqing as the research object,elaborates on the classification and universal characteristics of the affiliated spaces under overpasses,and selects 21 spaces under bridges to conduct a preliminary analysis of their landscape vitality status.Based on the analysis of landscape perception theory,Alexander pattern language,environmental behavior theory,and other theories,the factors affecting the vitality of the landscape under the bridge are divided into three aspects: natural environmental factors,material environmental factors,and event environmental factors.By using literature search,behavioral observation,and focus group interviews,the selection of landscape vitality indicator elements for the affiliated space under urban overpasses was completed.By combining the graying function and Analytic Hierarchy Process to calculate indicator weights,a landscape vitality evaluation system for the affiliated space under urban overpasses was constructed.Select 5 spaces under the bridge,including the space under the Egongyan Interchange,the space under the Wulidian Interchange,the space under the Sujiaba Interchange,the space under the Yanggongqiao Interchange,and the space under the Huanghuayuan Interchange,for landscape vitality evaluation.Based on the previous research and evaluation results,propose corresponding design strategies and apply them to design practice,in order to provide scientific guidance for the optimization and transformation of the landscape of the affiliated spaces under the urban overpass in the future.The main research results of the paper are as follows:(1)Provide a basis for the analysis of factors affecting the vitality of the landscape under the bridge and the selection of evaluation objects in the future.Based on relevant theories,the influencing factors of the landscape vitality of the affiliated space under urban overpasses were analyzed from the perspectives of natural environment,material environment,and event environment.By conducting research on 21 affiliated spaces under overpasses in the main urban area of Chongqing,the common problems of space utilization under bridges were summarized,including low space utilization rate,inconsistent functional supply and demand,low landscape quality,and insufficient management and operation.(2)We have completed the construction of a landscape vitality evaluation system for the affiliated space under urban overpasses,which includes five criteria layers with weights: natural vitality(0.0824),location vitality(0.2139),spatial vitality(0.2805),facility vitality(0.3386),and cultural vitality(0.0846);There are 19 indicator layers,ranking from high to low in terms of weight: number of activity facilities(0.1489),convenience of entrances and exits(0.1260),number of activity spaces(0.0942),aesthetics of small building(0.0805),number of recreational facilities(0.0721),pedestrian system(0.0592),peripheral population density(0.0539),plant aesthetics(0.0514),richness of activity types(0.0490),terrain design and processing(0.1671)Convenient service facilities(0.0362),spatial scale suitability(0.0357),surrounding land mix(0.0341),site protection and safety(0.0272),historical,cultural and urban characteristics(0.0198),microclimate comfort(0.0197),noise interference(0.0174),spatial management and maintenance(0.0158),and plant coverage(0.0113).(3)Five typical ancillary spaces under overpasses,including Egongyan Interchange,Wulidian Interchange,Sujiaba Interchange,Yanggongqiao Interchange,and Huanghuayuan Interchange,with a higher level of development,were selected for evaluation.The results showed that the vitality of the landscape space under the bridge ranked from high to low in descending order: Egongyan Bridge,Huanghuayuan Bridge,Sujiaba Bridge,Wulidian Bridge,and Yanggongqiao Bridge.Among them,the space under the bridge has a significant improvement in terms of plant aesthetics,convenience of entrances and exits,suitability of activity spaces,number of activity spaces,noise interference,number of activity facilities,space management and maintenance,urban characteristics,and cultural expression(4)According to the current situation of the survey area and the evaluation results,five general strategies are proposed from the aspects of nature,location,space,facilities and culture,namely,microclimate comfort and plant landscape construction,reachability improvement and urban space connection,functional diversity and space optimization,facility improvement and atmosphere creation,operation management and cultural experience,and three spaces with low evaluation scores are selected for optimization design practice,Provide guidance and reference for the optimization and transformation of the landscape of the affiliated space under urban overpasses in the future.