Research On Road Network Structure Of Small Towns Based On Geometric Topology

Modern urban construction is strongly influenced by external intervention,and urban space seems to be a planned space.However,from the perspective of urban development after the implementation of the plan,not all urban spaces are completely developed according to the planning layout,and there are cases where they are opened.In addition,China’s small towns have a large base and few guidelines.It is necessary to find the law of sustainable development as soon as possible in order to guide the spatial development of small towns and bring some references for road network reconstruction and expansion and land use planning from a new perspective.Starting with the topological structure of the road network,this paper focused on the cohesive structure to guide the layout and hierarchical structure of the road network.Firstly,this paper expounded the applicability of spatial syntax in the study of road network in small towns,and established an index system to describe the road network through topological data such as choice.The influences of aspect ratio,connection structure,density distribution and density on the structure of road network were studied by constructing road network model with control variables,which can provide reference for the optimization of road network.The results showed that the recommended form of road network in small towns was:the ratio of length to width was close to 1,the density of network was between 4.4km/km~2~8.4km/km~2,and the road network structure had its own advantages and disadvantages,so it was necessary to choose tree or network structure according to the nature of land use.Then the small towns were divided into three categories.Three small towns in Jiangsu were selected to analyze their road network structure characteristics.The road network was described by four indicators:permeability,accessibility,choice and comprehensibility.The differences,linkages and internal development laws between different types of small towns were summarized and analyzed by using the spatial syntax software Depth Map.The results showed that the higher the degree of development was,the more regular the road network was and closer to the grid road network.At the same time,the location of the market town was inevitably related to the accessibility center.With the development of economy,the accessibility center gradually presented the characteristics of circle layer.In addition,the degree of road selection played a guiding role in the road grade.Finally,the level of the topological value of the case town was analyzed.Based on the relationship between accessibility and land use,and the requirement of road conditions for selection degree,the optimization suggestions for road network reconstruction and expansion were put forward.Although the angle was relatively single,it did not lose relevance.Reasonable combination of land use and road network accessibility,reasonable matching of traffic volume and road network grade conditions will make the best use of road network structure.This paper studied the road network of small towns from a new angle,and provided a reference for the development direction of small towns.