Analysis Of Impact Of Road Network Form And Road Network Density On Urban Parks Accessibility

As an "oasis" in the city,urban parks conducive to beautifying the appearance of the city,softening the contours of the city,easing the land pressure,and promoting the hydrological and meteorological balance,and providing a social gathering place for people's daily life,which can please the mind and body and reduce the occurrence of crimes.At present,the economic development is too fast,traffic system planning cannot be consistent with the construction of urban park.Road planning is often blind construction,"road less road,bridge less bridge",making the urban park green as the "lung of the city" into a passive state.Unable to keep up with the pace of urban construction,and unable to meet people's needs.Therefore,from the perspective of accessibility,what kind of form is the best for urban road network selection,and what is the appropriate range of urban road network density? How to choose the location of the park in the existing urban road network? How to combine the relationship between the citizens and the urban park to properly optimize the road network,so that the road network construction can better meet the people's access to the urban park,these issues have become important focus of urban managers and builders.Based on Arc GIS software,this paper extracts typical road network forms in the city,simulates the service area of urban park in different road network densities and road network forms,and analyzes the accessibility of urban park in different formats,including check network,circle emanation network,mixed network and dendritic road network.The influence of road network density and road network form on the accessibility of urban parks is discussed,and its mechanism of action is revealed.The research results are as follows:(1)In different road network forms,the influence of road network density on the accessibility of urban parks is different.In check networks and mixed networks,as the density of road networks increases,and the accessibility of urban park green increases first and then decreases slowly.There are different optimal density intervals.In the actual planning,the number of radiated roads in the circle emanation network is limited,so the road network density is in the medium to low density interval,and the accessibility of the urban park increases rapidly with the increase of the road network density.(2)In the same density interval,the location of the urban park in different road network forms affects its accessibility.In the circle emanation road network: when the road network density is low,the accessibility of the urban park in the edge area(at the intersection of the radiation road and the loop)is significantly better.When the road network density is moderate,the accessibility of the urban park in central area is better than that of the edge.In the mixed network: whatever the road network density is low,moderate or high,the accessibility of the urban park in central area is better than that of the edge area(at the intersection of the radiation road and the check road).The dendritic road can not be connected into a network structure,and the overall road network density is low.The relationship between the accessibility of different locations is: at the intersection of branch road and main road ? close to the borders of branch road and main road > on the branch road > at the end of the branch road.(3)In the same density interval,the accessibility of urban park is different in different road network forms.Low density interval(road network density <5 km/km2): check network> dendritic road network > circle emanation network.Medium to low density interval(5-10 km/km2): mixed network > check network > circle emanation network.Medium to high density interval(10-15 km/km2)and high density interval(road network density >15 km/km2): mixed network > check network.Based on the comprehensive analysis results,the influences of different road network forms and different densities on the accessibility of urban parks are discussed,which provides theoretical reference and practical guidance for the site layout of urban park,surrounding road design and urban overall road network planning.