Analysis And Optimization Of Urban Spatial Structure Based On Multi-source Data And Space Syntax

At present,with the urban development of transforming from "incremental expansion" to "inventory exploration",the urban structure and form constantly adapt to the changing requirements of the times.It is of great significance to improve the layout of urban functions and clarify the optimization direction of land using structure,which can improve the efficiency and quality of urban space use and connect the plans of national land space in the new era.In recent years,due to the development of new data environment and emerging methods,multi-source data and spatial network analysis have been used in urban research to explore urban functional structures and road network forms.Research on urban spatial structure which is based on multisource data and space syntax is helpful to obtain the spatial allocation of urban resources dynamically and realize fine space management.Based on multi-source data such as Point of interest(POI)data,Open street map(OSM)data and Baidu Map,as well as various versions of the city overall planning,this paper,which takes the central city of Nanchang as the research object,using Kernel Density Estimation and quantitative identification of urban functional areas to analyze the spatial distribution characteristics of Nanchang’s urban functions and combining the Spatial Design Network Analysis(s DNA)system,which inherited the social network analysis method and improved the space syntax,to analyze the morphological characteristics of the urban road network.Then,the matching degree between function distribution and road layout is explored,and three combination Spaces of POI density and road space network efficiency are obtained.Then,the reasonable matching degree of each partition is divided into three categories according to the proportion of three types of space.Comprehensively analyzes existing problems in the spatial structure of central urban area and proposes relevant optimization strategies,The main research conclusions are as follows:(1)Using POI data to analyze the characteristics of urban functional spatial structure,it is found that the central urban area of Nanchang presents a two-center structure which is dominated by the old urban area and Honggutan area as the central core area and develops differently in regional groups.In terms of land using,the functional land use presents different spatial agglomeration characteristics.As can be seen from the quantitative identification results of functional areas,mixed functional areas and single functional areas present a "core-periphery" distribution pattern,and high mixed functional areas are mainly distributed in the core areas centered,showing strong agglomeration.(2)Using space syntax theory and s DNA system to analyze the morphological characteristics of urban road network,it is found that urban road network is featured by circle-like structures.Reflected by the distribution of two metrics of integration degree and two-phase travel degree,The network with high integration degree presents a "three-way" group layout network which is distinguished by the center of the old city and Honggutan district as the core,and the network with high travel degree shows the distribution characteristics of "network corridor".From the perspective of spatial configuration,the regional space with high efficiency of road space network presents the development trend of "single core-circle layer".(3)By exploring the coupling relationship between function and form,the matching degree of each zone is divided into three categories: reasonable(Honggutan District,high-tech district,Qingshan Lake District,Xinjian District),more reasonable(Jingkai District,airport Economic Zone,Donghu District,Xihu District)and low reasonable(Qingyunpu District,Wanli District).And combined with the distribution of functional elements and road network capacity and other spatial influencing factors to analyze the causes.(4)On the basis of spatial structure analysis,in view of the overall development of space,suggestions are put forward to further relieve the functional bearing pressure of the core area,promote the positive interaction between the functional distribution and traffic layout,and accelerate the coordinated and sustainable development of urban people and land.