Analysis of Urban Agglomeration Network Structure Based on Baidu Migration Data: A Case Study of the Guangdong-Hong Kong-Macao Greater Bay Urban Agglomeration

The inter-city linkage heat data provided by Baidu Migration is employed as a characterization of inter-city linkages in order to facilitate the study of the network linkage characteristics and hierarchical structure of urban agglomeration in the Greater Bay Area through the use of social network analysis method.This is the inaugural application of big data based on location services in the study of urban agglomeration network structure,which represents a novel research perspective on this topic.The study reveals that the density of network linkages in the Greater Bay Area urban agglomeration has reached 100%,indicating a mature network-like spatial structure.This structure has given rise to three distinct communities:Shenzhen-Dongguan-Huizhou,Guangzhou-Foshan-Zhaoqing,and Zhuhai-Zhongshan-Jiangmen.Additionally,cities within the Greater Bay Area urban agglomeration play different roles,suggesting that varying development strategies may be necessary to achieve staggered development.The study demonstrates that large datasets represented by LBS can offer novel insights and methodologies for the examination of urban agglomeration network structures,contingent on the appropriate mining and processing of the data.

The Study on the Evolution of Urban Spatial Structure in Zhuhai City Based on Spatial Syntax

With the deepening of the Guangdong-Hong Kong-Macao Greater Bay Area strategy and the accelerated integration and development of the east and west sides of the Pearl River Estuary,Zhuhai’s hub position is becoming more and more prominent.The city of Zhuhai has a dense water network and is divided into two urban areas,the east and the west,under the influence of the Mordor Gate waterway.Based on the theory of spatial syntax,this paper carries out an analytical study on the urban spatial structure of Zhuhai,identifies the distribution characteristics of urban POIs,and provides theoretical support for the urban development of Zhuhai.

Study on Spatial Structure of Rural Tourism in Wuhan Urban Agglomerations

Spatial structure of rural tourism in the urban agglomerations of Wuhan was analyzed by comprehensively studying relevant documents about rural tourism,and reviewing previous researches on the concept and spatial structure of rural tourism.Through investigating rural tourist resources in the study area,resource advantages and characteristics of 9 cities were introduced,and the Gini Coefficient was taken to quantitatively analyze spatial patterns of its rural tourist villages,the obviously imbalanced concentration of these villages was pointed out.By measuring connectivity and accessibility of regional spaces in the study area,its traffic connectivity was proved moderate,and accessibility of each tourist village and town was fine.Then an optimized spatial structure was proposed for the rural tourism development in Wuhan Urban Agglomerations,that is,"one core,one belt and three districts".

Stability of Spatial Structure of Urban Agglomeration in China Based on Central Place Theory

This paper brings forward the concept of stability of the spatial structure of urban agglomeration(UA)based on Central Place Theory by introducing centrality index and fractal theory.Before assessment,K=4 is selected as parameter to calculate centrality index and fractal dimension(K represents the quantitive relationship between city and the counties in Central Place Theory),and then found the number of nodes,the type of spatial structure,the spatial allocation of nodes with different hierarchy affecting the stability of spatial structure.According to spatial contact direction and the level of stability,UAs in China are classified into five types.Finally,it is posed as a further question that how to use hierarchical relation K=6 and K=7 in central place system to coordinate with the assessment of stability of soatial structure is brought forward.

Eco-spatial Structure of Urban Agglomeration

In terms of ecological theory, this paper makes a comprehensive analysis of the mutualism and co- evolutionary mechanism between the eco-spatial structure and socio-economic development of the urban agglomeration, and maps out optimized modes of the eco-spatial structure of the urban agglomeration. The analysis is a case study of the urban agglomeration on different levels of global, national, provincial and local scales, on the basis of those conclusions are drawn: 1) Within the scope of the urban agglomeration, the cities should be reasonably sized and appropriately densified; the spatial combination of the urban agglomeration ought to be orderly, and its eco-spatial structure ought to be optimized and efficient; the relationship between the economic society and eco-spatial environment ought to be that of mutual benefit and co-evolution. 2) “The mode of corridor group network” is a certain trend evoked from the spatial structure of urban agglomeration. 3) The eco-spatial structure of urban agglomeration under “the mode of corridor group network” can further increase the environmental capacity of urban agglomeration, and is in favor of the harmonious relationship between man and nature.

The Structure and Pattern of Urban Network in the Lanzhou-Xining Urban Agglomeration

In this paper,we use factor analysis to evaluate the urban comprehensive quality of each city in the Lanzhou-Xining(Lan-Xi)urban agglomeration.The time distance was obtained by using GIS spatial analysis,and the structure and pattern of the spatial network were analyzed by using the gravity model and social network analysis method.The results show that:1)The scale effect of the Lan-Xi urban agglomeration is gradually emerging,and it is gradually forming the urban agglomeration with Lanzhou and Xining as the core,the Lan-Xi high-speed railway as the axis,and a high-dense connection.2)Lanzhou and Xining are at the core of the Lan-Xi urban agglomeration,which has a strong attraction and spreads to neighboring cities.3)In the network structure of the Lan-Xi urban agglomeration,Lanzhou,Baiyin,Gaolan,Yuzhong,Yongdeng,Dingxi,Lintao,Xining,Ledu,Huangzhong,Ping’an,Minhe and Datong are located in the network core position,which have the superiority position and lead to the entire regional communication enhancement and the regional integration development.4)This urban agglomeration has significant subgroups,eight tertiary subgroups and four secondary subgroup;the tertiary subgroups which compose secondary subgroup have a close connection and mutually influence each other.5)The Lanzhou Metropolitan Area and the Xining Metropolitan Area have an important impact on the surrounding cities,and the peripheral cities are basically controlled by the central city.The Dingxi subgroup,Lintao-Linxia subgroup,Gonghe subgroup have more structural holes than the subgroups within the Lanzhou Metropolitan Area and the Xining Metropolitan Area,so the peripheral cities of these subgroups have relatively less connection with surrounding cities.

Spatial Structure of Central Places in Jilin Central Urban Agglomeration, Jilin Province, China

Using the radius of gyration from fractal theory, this paper describes the calculation of fractal dimensions for the four tiers of central places in the Jilin Central Urban Agglomeration(JCUA), Jilin Province, China and the structural characteristics of each tier: 1) the 1st tier central place, Changchun Proper(not including Shuangyang District), provides the most service functions and has the most stable primate position; 2) the 2nd tier central places, Jilin Proper, Siping Proper, Liaoyuan Proper and Songyuan Proper have unclear statuses and do not provide certain functions; 3) the 3rd tier central places comprise 23 county-level cities, counties and urban districts(including Shuangyang District of Changchun), exhibiting a dense spatial structure that agrees with theory; 4) the 4th tier contains the largest number of central places(248 designated towns), but they are loosely distributed. In this study, a spatial image of the JCUA was created, based on vectorized data of the urban settlement distribution, which was then modified and abstracted to create a hexagonal network covering the JCUA. Compared to the traditional central place model, the modified spatial image conforms to the K = 3 principle. In reality, however, the growth of some 3rd tier central places should be increased with the cities being upgraded to the 2nd tier so as to overcome that tier′s functional deficiency. The loose distribution in the 4th tier should also be changed. This apparent anomaly can be explained by the fact that the classic hexagon model used to describe the way market areas layout does not exist in the real world. However, this should not be viewed as an obstacle to using central place theory. If its assumptions are properly applied, it can still assist research into the spatial structure of regions.

An Empirical Study of Urban Spatial Structure Based on Social Network Analys is: A Case Study of Urban Update Unit in Shenzhen as an Example

Through sorting out the data of urban renewal units in Shenzhen from 2010 to 2016, this paper quantitatively analyzed the spatial characteristics of urban update from two dimensions of location conditions and functional attributes, using social network analysis, community discovery and other methods.The research found that:(1) the urban functional network formed based on the update unit had obvious spatial agglomeration and hierarchical characteristics, forming the central-peripheral structure of "two mains and five sections", covering basically all the developed areas of Shenzhen city, and presenting the overall spatial structure of "dense west and sparse east";(2) based on the functional space of urban update unit, five relatively closely connected community groups were formed, whose characteristics mainly included:spatial integration, spatial coupling and spatial spillover effect;(3) the spatial structure formed by urban updates basically conformed to the spatial structure defined in the plan of "the 10 master plan".

Tourism Spatial Structure in Urban Agglomeration of the Greater Bay Area and Its Optimization

With the rapid development of economy,China’s urbanization process is accelerated.As major urban cluster center,Guangdong-Hong Kong-Macao Greater Bay Area is regarded as one of the most representative areas with the highest openness and the strongest economic vitality.Under the background of new era,main purpose of making development strategy of the Greater Bay Area is to build a world-class city cluster with great vitality,and establish a world-class science and technology innovation center with great influence.It also lays a good foundation for strengthening the construction of the belt and road initiative in China,and improves quality of life in the cooperation zone between the mainland and Hong Kong and Macao.Under the background,the tourism industry has new challenges,and the tourism spatial structure should be more closely linked.In this paper,tourism spatial structure of 9+2 urban agglomeration in the Greater Bay Area is taken as core research objective,and tourism resource of the urban agglomeration,and development of tourism economy and perfect transportation network in each city are analyzed.According to research results,the targeted suggestions and optimization methods are obtained.

FORMATION MECHANISM AND SPATIAL PATTERN OF URBAN AGGLOMERATION IN CENTRAL JILIN OF CHINA

Urban agglomeration is made up of cities with different sizes to be linked by traffic network in a given area, and it is an inevitable result when urbanization reaches a certain level. Taking urban agglomeration in central Jilin (UACJ) as an example, this article analyzes the formation mechanism and spatial pattern of urban agglomeration in the less-developed area. First, the dynamics of UACJ has been analyzed from the aspects of geographical condition, economic foundation, policy background, and traffic condition. Then the development process is divided into three stages-single city, city group and city cluster. Secondly, the central cities are identified from the aspects of city cen- trality, and the development axes are classified based on economic communication capacity. Finally, the urban agglo- meration is divided into five urban economic regions in order to establish the reasonable distribution of industries.

Measuring Network Configuration of the Yangtze River Middle Reaches Urban Agglomeration:Based on Modified Radiation Model

The objective of this study is to develop a framework for re-examining and re-defining the classical concepts of spatial interaction and reorganization in the urban system.We introduce a modified radiation model for spatial interactions,coupled with migration big data,transport accessibility algorithm,and city competitiveness assessment for efficient distribution of the inter-city flow through the network.The Yangtze River Middle Reaches(YRMR)urban agglomeration(UA)is chosen as the case study region to systematically identify and measure its spatial configuration and to gain insights for other UAs‘sustainable development in China.The results are also compared with those computed by the classical gravity model to systematically discuss the applicability of spatial interaction laws and models,and related practical policies for regional sustainable development are discussed based on the findings as well.The conclusions are highlighted below:1)Combining with the?city network paradigm‘and?central place theory‘can better express the spatial configurations of city systems in the context of?space of flows‘;2)The results validate the potentialities of a multi-analysis framework to assess the spatial configurations of city network based on the improved radiation model and network analysis tools;3)The applications of spatial interaction models should be considered according to the specific geographical entity and its spatial scale.

Impact of high-speed railway construction on spatial relationships in the Guanzhong Plain urban agglomeration

The Guanzhong Plain urban agglomeration is a response to the Belt and Road Initiative in Northwest China that aims to promote regional development.The direct impact of high-speed railway construction is to shorten the spatial-temporal distance among regions,improve the accessibility of regional transportation,and promote socioeconomic linkages.From the perspective of accessibility,this study analyzes the impact of high-speed railway construction on the spatial pattems and county-level economic relationships of the Guanzhong Plain urban agglom-eration.The results show that the construction of high-speed railway significantly improves regional accessibility,increases the potential for urban economic development,and gradually narrows the gaps in economic potential among cities.The construction of high-speed railway has increased the intensity of extenal economic relations among numerous counties in the Guanzhong Plain urban agglomeration,and most of the areas with increased connections are located in the direction of routes extension.The development of the internal economic network of the Guanzhong Plain urban agglomeration is unbalanced,and a complex network is gradually emerging with a few large cities at the core,but the construction of high-speed railway is changing the struicture of the economic network.In general,a certain degree of intrinsic coupling exists between regional accessibility change and the evolution of economic relations caused by high-speed railway,reflecting the requirements of the regional overall development strategy.

STUDY ON ECOLOGICAL SPACE OF URBAN AGGLOMERATION-Taking Wuxi City as an Example

From the angle of ecology,urban agg lomeration presents relevant types of landscape structure,which in-clude Patch,Corridor and Matrix.There are different landscape feature s and different problems in differen t development phases.This paper has put forward fi ve basic conditions for security pattern of landscape ecology of urban agglomeration,described quantitatively the featu res for landscape ecology in Wuxi,an d analyzed ecological background of spatial expan-sion and spatial organization of urb an development in Wuxi.From the angle of ecological land use and non-ecological land use,the paper has analyzed the featu res of land use and ecological distribution of land in the urban area.The s patial mod-el of cities and towns in Wuxi is composed of one metropolis,two urban zones and three development axes.This th esis has planned preliminarily ecologic al protection network at four levels in the urban region according to four layers.At last,combining landscape ecology with ur ban space,a tentative security pattern of landscape ecology has been pla nned in Wux-i,namely Source-Buffer Zone and Metropolis,Radiating Routes and Expan sion Direction of City,Strategic Point and Interac-tion between Cities and Towns,Inter-Source Linkage-Corridor of a Stabl e Landscape Structure.

Dynamic changes in urban land spatial inequality under the core-periphery structure in urban agglomerations

Relatively coordinated development among cities can typically promote the integration of the whole urban agglomeration,while urbanization of land has been found important to economic development in developing countries.Numerous studies have measured the urban land expansion in urban agglomerations.However,urban land spatial inequality under a specific spatial structure remains poorly understood.Here,we combined theβ-convergence model and the core-periphery structure to explore the dynamic changes in urban land spatial inequality in urban agglomerations.The Yangtze River Delta Urban Agglomeration(YRDUA)in China was selected as the study area.Indicators of urban land have been applied in conjunction with a modified conditionalβ-convergence model,while the existence of the core-periphery structure was tested by analyzing coefficients of the control variable.The results show that although the spatial inequality of urban land area had decreased during 2000–2020,the whole YRDUA had still shown an obvious core-periphery structure.Compared with urban land area,the spatial inequality of urban land economic density and population density had decreased more rapidly,and the core-periphery structure was less obvious.Our findings can help to improve our current understanding of urban agglomeration and serve as a scientific reference for the coordinated development of urban agglomerations.

SSP-RCP情景下京津冀城市群夏季热环境空间网络识别与评估

全球气候变化加剧和城市高温热浪频发,严重影响人居环境健康和社会可持续发展。该文综合GIS、形态学空间格局分析、电路理论和图论法等理论与技术,基于共享社会经济路径(SharedSocio-economicPathways,SSPs)与典型浓度路径(Representative Concentration Pathways,RCPs)联合情景框架的未来气候数据,定量识别2021-2100年低辐射强迫情景(SSP1-RCP2.6)、中等辐射强迫情景(SSP2-RCP4.5)和高辐射强迫情景(SSP5-RCP8.5)下京津冀城市群夏季热岛斑块时空格局并评估热环境空间网络时空演变过程和结构特征。结果表明:①2021-2100年京津冀城市群夏季热岛斑块类型以核心型和边缘型为主导,热环境源地数量、面积以及廊道数量、总长度和电流密度随时间和情景强迫性提升呈增加趋势,其中源地和廊道集中增长区域由南向北迁移,而廊道高密度区域始终位于城市群东南部;②京津冀城市群热环境空间网络的电流密度之和、夹点稳定性、网络闭合度、节点连接率和网络连接度与情景强迫性呈正相关,城市群发展的时空不均衡性是影响城市群热环境空间网络结构特征变化的重要原因。研究结果可为未来情景城市群热环境空间网络分析提供技术范式,也可为城市群空间协同发展主动应对气候变化风险提供理论参考。

高质量发展视域下城市群空间网络联系与人口长期均衡发展——基于成渝城市群的实证分析

在人口规模巨大的背景下,促进人口长期均衡发展、深入实施区域协调发展是我国高质量发展的必由之路。采用2006—2020年16个城市的面板数据,使用耦合协调度模型和修正引力模型分别测度成渝城市群16个城市在2006—2020年间的空间网络联系度与人口长期均衡发展水平,运用空间杜宾模型实证分析城市群空间网络联系对人口长期均衡发展的影响及其时空异质性和网络外部效应,发现:(1)城市群空间网络联系可促进本地人口长期均衡发展,但将在周边形成“集聚阴影”,产生不利于周边城市人口长期均衡发展的网络负外部效应。(2)成渝城市群空间网络联系对成都市、重庆市双核心城市以及绵阳市、宜宾市和泸州市三个副中心城市的人口长期均衡发展水平产生促进作用。随着行政级别的提升,城市网络联系逐渐由不利于周边城市人口长期均衡发展的负外部效应转变为促进周边城市人口长期均衡发展的正外部效应。(3)城市空间网络联系所产生的外部效应呈现先负后正,最后趋于收敛的倒S型,且在0-100公里的范围内形成“集聚阴影”,150-200公里范围内为城市网络联系发挥正外部效应的最优半径。(4)科技创新和创业活跃度的提升是城市空间网络联系促进人口长期均衡发展的关键渠道。

产业空间关联网络对城市群经济韧性的影响——基于长江中游城市群数据的实证分析

近年来,国内外各式冲击频繁加剧,各区域所面临的内外部环境不确定性与日俱增,因而提高经济系统的抵御、调整和转型能力,即增强经济韧性成为把握新发展阶段、贯彻新发展理念和构建新发展格局的题中之义。选取长江中游城市群内27个主要城市为研究对象,应用改进的引力模型构建2010—2019年长江中游城市群产业空间关联网络,并从社会网络分析的角度测算产业空间关联网络中心度特征,实证检验长江中游城市群产业空间关联网络的三大中心度特征对城市群经济韧性的影响。结果表明:产业空间关联促进了城市群经济韧性的提升,并且在金融环境好、市场化程度高的城市以及非工业城市中,产业空间关联对经济韧性的提升作用更加显著。进而提出有助于长江中游城市群产业高质量发展、经济韧性水平攀升的政策建议。

Comparison of spatial structures of urban agglomerations between the Beijing-Tianjin-Hebei and Boswash based on the subpixel-level impervious surface coverage product

Under the background of China's rapid urbanization, study on comparative analysis of the spatial structure of urban agglomerations between China and the US can provide the policy proposals of space optimization for the Chinese government. Taking the Beijing-Tianjin-Hebei(BTH) and Boswash as study area, we mapped the subpixel-level impervious surface coverage of the BTH and Boswash, respectively, from 1972 to 2011. Further, landscape metrics, gravitational model and spatial analysis were used to analyze the differences of the spatial structures between the BTH and Boswash. The results showed that(1) the area of the impervious surface increased rapidly in the BTH, while those remained stable in the Boswash.(2) The spatial structure of the BTH experienced different periods including isolated cities stage, dual-core cities stage, group cities stage and network-style cities stage, while those of the Boswash was more stable, and its spatial pattern showed a "point-axis" structure.(3) The spatial pattern of high-high assembling regions of the impervious surface exhibited a "standing pancake" feature in the BTH, while those showed a "multi-center, local aggregation and global discrete" feature in the Boswash.(4) All the percentages of the impervious surface of ecological, living, and production land of the BTH were higher than those of the Boswash. At last, from the perspective of space optimization of urban agglomeration, the development proposals for the BTH were proposed.

基于汽车企业联系的中国城市网络结构特征

为优化产业空间布局和推动区域均衡发展,企业联系视角下的城市网络已成为探究新型区域空间关系的关键。文中采用2000—2020年中国汽车企业上市数据,运用城市网络测度模型,深入探讨城市属性指标、联系结构以及距离分配规律,从而揭示基于汽车企业的城市网络结构特征。研究发现城市分布格局从散点逐渐过渡到片区扩散,直辖市和省会城市的中介控制作用极强,但各大城市的资源辐射能力具有较大异质性特征。城市网络联系结构呈现出中部“十字蛛网”,外围“梯菱骨架”的特征,联系强度的高值区域位于邻近区域和城市群之间。研究为优化区域协调发展提供参考借鉴。

多维要素流视角下环长株潭城市群空间网络结构特征

城市群空间网络结构特征分析有助于解析城市发展驱动力,减弱城市极化现象,本研究运用修正的引力模型、多维网络度量模型和隶属度模型测定环长株潭城市群内外部空间网络联系强度,分析其网络特征与作用方向,利用社会网络分析法研究城市群空间格局与板块效应。结果表明:(1)内外部总体多维要素网络表现相对一致,联系强度以长沙为中心逐渐向外圈降低。(2)在省内要素网络中,长沙市“一城独大”态势明显;在省际网络中,岳阳市在多维要素网络中表现突出,与武汉都市圈联系密切。(3)环长株潭城市群点度中心度内外部网络差异大,整体网络中介水平低,不利于吸引外部要素交流。其内部综合联系空间网络分为4个凝聚子群,外部综合网络仅分为2个凝聚子群。表明环长株潭城市群仍是以内部联系为主,对外连通性较弱。