Study On The Relationship Between Road Network Density And Pedestrian Accessibility Of Urban Public Open Space

In the book "The life and death of the big cities of the United States",Jane Jacopo talked about "the basic characteristics of cities are human activities",while urban public open space is often an important carrier of crowd activities.As an important place for interaction between human and nature,people and people,it has significant environmental benefits,social benefits and health benefits.Walking is the human instinct as a erectus,and is also the basic mode of transportation for residents’ daily travel.As an important destination for the residents,the accessibility of the urban public open space embodies the public and service efficiency of the space.At present,the accessibility of public open space has gradually become an important evaluation factor of urban walkability,and the influencing factors of pedestrian accessibility are complex and diverse.Summarizing the previous researches on the factors that influence accessibility,this paper further puts forward the influencing factors of pedestrian accessibility in urban public open space,namely,"human needs","public open space attraction" and "travel cost".As an important factor of "travel cost" factor,road network density has a significant impact on the accessibility of public open space.However,there is little quantitative research in this field at present in China.In view of this,this paper uses the network analysis method,to the public open space in Nanshan District around the city of Shenzhen 800 m walking distance as the basic research unit,quantitative evaluation of Nanshan District public open space pedestrian accessibility and road density,then we analyze the relationship between the two,and analyze the challenges faced by the current road network density in China and optimize the road network density to optimize the open access accessibility of public open space.Among them,the correlation analysis of the two includes two aspects of correlation analysis and matching degree analysis.In correlation analysis,using Pearson correlation analysis method;the matching analysis,first use the Z-score standard method will walk up to the road network density value and value standard,and from the overall mean compared with the standard value of the absolute value of the difference of the two dimensions.The pearson correlation analysis results show that road network density is not a key influencing factor for urban public open space pedestrian accessibility,and the matching degree between supply and demand of public open space in space is the important influencing factor of pedestrian accessibility;The matching analysis results show that there is a big departure from the matching degree of the two groups(i.e.,high road network density and poor pedestrian accessibility,low road network density and good pedestrian accessibility).In addition,public open space with a low road network density within 800 m walking distance accounts for half of the total number.From this result,the main reasons for the low road network density in Shenzhen and even in the country are can be listed as follows.The first one is to simplify the road classification in our country,the second one is the development mode of residential district to form a "Street area,thin road network" road pattern;the third one is the current urban renewal damage the old city road texture.And,with the high-density development of cities,the three-dimensional public open space will become a trend,and its use path will also be diversified.In this context,indexed urban planning will lose its guiding significance at the three-dimensional level,and planners will also face the challenge of using the public open space after its three-dimensionalization.