The Spatial Distribution,Accessible Metrics And Optimal Allocation Of Urban Leisure Venues Based On Geographic Big Data

Leisure is the fourth fundamental urban function besides living,commuting and working.With the rapid socio-economic development,the post-industrial era comes with people’s leisure needs increasing.To achieve people-oriented neo-urbanization,human society has entered the leisure era.Hence,urban leisure has become a frontier subject.The spatial characteristics of urban leisure are closely related to people’s leisure convenience,social cohesion,urban vitality and cities’intelligent development.Considering that leisure facilities are the spatial carriers of leisure activities,to some extent,urban leisure is essentially a spatial science.At present,leisure-relevant scholars mainly focus on studying leisure from the psychological,economical and philosophical perspectives.However,researches on urban leisure from the geospatial perspective are quite insufficent.The advent of the Big Data Era as well as the geographical spatial analysis technology gradually maturing provides us a great opportunity to explore the tempo-spatial regularities of urban leisure.Therefore,systematic research on the spatiality of urban leisure becomes a hot academic issue.In this study,Wuhan city is selected as the study site.Based on the taxonomy of leisure（culture,tourism,entertainment and sports）,the geographical big data（Points of Interests,real-time navigation data from Baidu Map,mobile phone signal data,etc.）and a series of classic spatial analytical techniques（point clustering analysis,spatial autocorrelation,gradient analysis,fitting analysis,network analysis,genetic algorithms,etc.）,this study explores the spatiality of urban leisure from three aspects-spatial distribution,accessible metrics and optimized allocation.The main research contents and conclusions are as follows:（1）The spatial distribution pattern of leisure venues in Wuhan City are in the form of clusters with obvious urban-rural distribution differences and inter-district unevenness.That is,the spatial distribution of urban leisure venues is imbalanced.The clusters of Wuhan’s leisure venues are three levels.There are two 1^st-level clusters,respectively in the Hankou Township,the Hongshan Township with no one in Hanyang Township.There are ten 2^nd-level clusters,distributed uniformly in Jianghan district,Wuchang district,Hongshan district and Hanyang district.A great number of 3^rd-level clusters are distributed along the two sides of the Yangtze river,resembling the Eyes of Leisure in Wuhan.This spatial distribution pattern of urban leisure venues is closely related to population（population density）and economic（business center）factors.In most regions where the population density is high,as is the density of leisure facilities,and vice versa.For very few local regions,the situation is the opposite.In addition,the business center has great attraction for the site selection of urban leisure facilities.The business center evenly covers nearly 80.76%of the urban leisure facilities.On this basis,we spatially quantify the urban leisure venues through the gradient analysis method based on the identified hierarchical polycentric city configuration（“1+6+3”）.Specifically,the spatial gradient changing regularity（30 buffers with the 1km from city centers）of urban leisure venues well fits the power function.This illustrates that,with the increase of distance from the city centers,the number of recreational facilities is constantly decreasing.The inflection point occurred in the 5^thbuffer zone（i.e.,5 kilometers away from city centers）,which is almost just the 3^rd Road Loop in Wuhan.Specifically,within 5 kilometers from the city centers,there is a great number of leisure venues and their distance attenuation effect is obvious.Outside the inflection point（5 km away from the city centers）,the number of leisure venues is small,and with the slight decrease with the distance increasing from the city centers,the decline trend of leisure facilities density gradually slows down and becomes gentle.This shows that the third ring road of Wuhan city delineates the boundary of the urban core leisure area as well as the city core.（2）The urban leisure venues are spatially quantified.Taking the gymnasium and the museum as examples,this study adopts the network analysis and real-time multi-transit modes for measuring gymnasiums’walkability and museums’multi-transit tempo-spatial accessibility.The research results reflect the status quo of social justice（e.g.,health justice and cultural justice）.The spatial distribution of gymnasiums’walkability is imbalanced in the form of clusters.As one sort of increasingly populous sportive leisure venues,the gymnasium improves citizens’quality of life and promotes their healthy lifestyle.Increasing studies indicate that public health closely relates to the spatiality of urban leisure venues.Under this context,we take the gymnasium as the research object and examine the implicit health justice.We found four fitness clusters in the core area of Wuhan,locating in the Three Townships of Wuhan respectively.However,the area of the gymnasium aggregation in Hanyang is the smallest and that of Hankou is the largest,which reflects the regional distributive unevenness and the implicit health injustice.In addition,by spatially visualizing the 10-minute and 20-minute walkability from the residential communties to the gymnasiums,the extent of health injustice at the community scale is also demonstrated.These results provide fine-scale spatial observations of urban health issues and promote more walkable communities and healthier urban development and construction.The spatial distribution of museums in Wuhan is imbalanced,and the real-time multi-mode transportation accessibility also presents spatial heterogeneity.Wuhan is in the process of being built into a museum city,which is crucial to promoting the city’s soft power,competitiveness,influential power and attractiveness.The Lorentz Curve shows that the distribution of museums is uneven at the district scale,with the distribution per capita more severe compared with that per spatial unit.The spatial accessibility distribution of accessibility by walk,public transport presents spatial heterogeneity,but with similar spatial regularities.That is,the communities around the intersection of the Yangtze River and the Han River are with the highest accessibility.Through spatializing the cultural leisure accessibility circles（10-20-30 minutes）,we find that the lowest accessibility is by public transportation.Hence,public transportation planning should be given priority on a basis of improving the cultural accessibility of the city.This study provides the decision-making support for cultural city construction and sustainable urban spatial development.（3）The cultural leisure subclass（i.e.,self-service library）is adopted as an example.By the non-dominated sorting genetic algorithm with elitist strategy（NSGA-II）,based on two scenarios（Scenario 1:considering no existing self-service library and Scenario2:considering existing self-service library）with the optimized objectives（Objective 1:the largest population coverage,Objective 2:the shortest of accessible time and Objective 3:the minimum number of self-service libraries）in the urban core of Wuhan city.Scenario 1:We optimize the allocation of self-service libraries and find that with the number of self-service libraries increasing,the coverage area becomes larger and the accessible time becomes shorter.However,considering the construction cost,we select the least number of self-service libraries with the population coverage rate of50%,60%,70%and 80%respectively with the relevant shorter accessible time,and found that 44,62,84 and 121 self-service libraries need to be built,respectively.They also had the respective accessibility time of 20.6 minutes,17 minutes,14.2 minutes and11.8 minutes.This means when the number of self-service libraries reach 121,then the proportion of the population coverage is large（80%）and the accessiblity time is short（11.8 minutes）.Scenario 2:We optimize the self-service library and select the spatial allocation of the least number of self-service libraries with a population coverage rate of 50%,60%,70%and 80%respectively with the shortest accessible time,and find that 50,66,89and 125 self-service libraries need to be built,respectively.And their corresponding accessibility time is 20.4 minutes,16.4 minutes,14.6 minutes and 11.8 minutes.This means that the number of libraries can be 125,then the proportion of the population coverage reaches 80%and the accessible time are ideal（11.8minutes）.As a new-type subclass of cultural leisure venues,the self-service library relates to promoting the reading penetration rate and the construction of cultural city.The comparison of these two scenarios shows that when the proportion of population coverage is the same,the accessibility time of the two scenarios is not significantly different,and the number of self-service libraries required is obviously higher in Scenario 2 than in scenario 1,which indicates that the total cost required in Scenario 2is higher than that in Scenario 1.Scenario 1 provides a reference for Scenario 2,but considering that 29 self-service libraries have been established,Scenario 2 is more in line with the actual situation of saving subsequent additional costs.This study is conducive to enriching urban leisure spatial theories,methodologies and empirical cases as well as facilitating the leisure-led spatial policy and decision-making,thus further promoting people-centered neo-urbanization,sustainable urban spatial development and harmonious people-land relationship.