Urban agglomeration has been the inevitable result of China's rapid industrialization and urbanization over the last 30 years. Since the early 2000s, urban agglomeration has become the new regional unit participating in international competition and the division of labor. China has declared urban agglomeration the main spatial component of new types of urbanization over the next decade as clarified at the first Central Urbanization Working Conference and in the National New-type Urbanization Plan (2014?2020). However, research on urban agglomeration remains weak and needs to be strengthened. From 1934 to 2013, only 19 papers published in Acta Geographica Sinica contained the theme of urban agglomeration (0.55% of the total number of articles published) and the first paper on urban agglomeration appeared less than 10 years ago. Despite a small number of divergent studies, this work has contributed to and guided the formation of the overall pattern of urban agglomeration in China. For example, spatial analyses have promoted the formation of the fundamental framework of China's urban agglomeration spatial structure and guided the National New-type Urbanization Plan; spatial identification standards and technical processes have played an important role in identifying the scope and extent of urban agglomeration; serial studies have facilitated pragmatic research; and problems with the formation and development of urban agglomeration have provided a warning for future choices and Chinese development. Future research into urban agglomeration in China should (1) review and examine new problems in China's urban agglomeration options and cultivation; (2) critically consider urban agglomeration when promoting the formation of the 5+9+6 spatial pattern; (3) rely on urban agglomeration to construct new urbanization patterns such as 'stringing the agglomerations with the axis, supporting the axis with the agglomerations'; and (4) deepen national awareness about resources, environment effects and environmental carrying capacity in high density urban agglomerations, management and government coordination innovation, the construction of public finance and fiscal reserve mechanisms, the technical regulation of urban agglomeration planning, and standards for identifying the scope and extent of urban agglomeration.

中国的城市群是近30年来伴随国家新型工业化和新型城镇化发展到较高阶段的必然产物,自21世纪初期城市群成为国家参与全球竞争与国际分工的全新地域单元之后,中国连续10年把城市群提升为推进国家新型城镇化的空间主体,首次召开的中央城镇化工作会议和《国家新型城镇化规划 (2014-2020年)》进一步明确了城市群作为推进国家新型城镇化的主体地位。然而,城市群在中国的研究目前尚处在亟待加强的薄弱环节。系统总结从1934-2013年的80年间发表在地理学报的城市群主题论文,只有不到19篇,仅占总篇数的0.55%,不仅发表篇数少,而且发表时间短,首次发表城市群研究成果不到10年,研究单位和作者群体集中,研究内容瞄准国家需求但比较发散。即便如此,仅有的城市群研究成果还是对国家城市群总体格局的形成起到了引领作用,做出了重要贡献。具体体现在,提出的城市群空间格局推动国家形成了中国城市群空间结构的基本框架,引导国家新型城镇化规划把城市群作为推进新型城镇化的主体形态,提出的城市群空间范围识别标准与技术流程对界定国家城市群范围起到了重要作用,提出的城市群系列研究领域带动城市群的研究向着纵深与实用方向拓展,提出的中国城市群形成发育中存在的问题对未来城市群的选择与发展起到了警示作用。以这些研究进展和成果为基础,未来中国城市群选择与培育的重点方向为：以问题为导向,深刻反思检讨中国城市群选择与发育中暴露出的新问题;以城市群为主体,重点推动形成“5+9+6”的中国城市群空间结构新格局;以城市群为依托,重点推动形成“以轴串群、以群托轴”的国家城镇化新格局;以国家战略需求为导向,继续深化对城市群形成发育中重大科学问题的新认知,包括深入研究城市群高密度集聚的资源环境效应,科学求解城市群高密度集聚的资源环境承载力,创新城市群形成发育的管理体制和政府协调机制,研究建立城市群公共财政制度与公共财政储备机制,研究制定城市群规划编制技术规程与城市群空间范围界定标准等。

Urban agglomerations are important carriers to promote the regional socio-economic development and participate in the international competition in the advanced stage of urbanization. And the high traffic accessibility is essential for the high-quality development of urban agglomerations. According to the 2h access goal of urban agglomeration proposed in the Outline of Building a Country with a Strong Transportation Network, taking three national urban agglomerations in the Yangtze River Economic Belt as the study area, this paper employs the weighted average travel time as the measurement index and constructs the field model and the gravity model to comparatively analyze the pattern characteristics of 2h travel circle of all cities and central cities in the three urban agglomerations. The results show that: firstly, the weighted average travel time of all the cities in the three urban agglomerations shows the “circle-type” spatial pattern that continuously expands from low (the center) to high (the periphery). Specifically, the 2h travel corridors exhibits the “>” pattern in Yangtze River Delta urban agglomeration and displays the “cross” pattern in Chengdu-Chongqing urban agglomeration; but Yangtze River Middle Reaches urban agglomeration has not formed 2h travel corridors. Secondly, the spatial distribution of the 2h travel circle of the central cities is significantly affected by the geographical location: the closer to the geometric center of the urban agglomeration, the larger the coverage of 2h travel circle. Moreover, the spatial distribution of the hinterland is affected by the comprehensive scale of the central city. And there are large differences in the spatial distribution of the 2h travel circle and the hinterland among the three urban agglomerations. Thirdly, there are significant differences in the connectivity of 2h travel circle among different urban agglomerations, which shows the pattern of multiple circle superposition and economic connection. The Yangtze River Delta urban agglomeration has initially formed the hierarchical network structure of central cities, while the Yangtze River Middle Reaches and Chengdu-Chongqing urban agglomerations stay at the development stage of connection axis. Fourthly, the spatial arrangement of the transport infrastructure has significant influence on the connectivity of 2h travel circle of the central cities. The high-density expressway network plays an important role in improving the connectivity of 2h travel circle in central cities at the scale of urban agglomeration. From the viewpoint of the structure of connectivity, urban agglomerations can be classified into three types: polycentric-network type, polycentric-cluster type and bicentric-radial type.

城市群作为城镇化高级阶段区域社会经济发展和参与国际竞争的主要空间载体,良好的交通通达性是其高质量发展的必要条件。以《交通强国建设纲要》提出的城市群2h通达目标为研究视角,以长江经济带3个国家级城市群为研究对象,选取加权平均出行时间作为测度指标并引入场强和引力模型,对比分析3个城市群所有城市与中心城市两个层级2h出行交通圈格局特征。研究发现：① 3个城市群出行交通圈均表现为从中心向外围地区呈现出由低到高连续扩大的“圈层式”空间格局特征,且长三角和成渝城市群分别形成了“>”字型和“十”字型2h出行廊道,但长江中游城市群尚未形成2h出行廊道。② 城市群中心城市2h出行交通圈的空间分布受区位条件影响较大,越接近区域几何中心则2h出行交通圈覆盖范围越大,而影响腹地受中心城市综合规模的作用明显,3个城市群各中心城市2h出行交通圈和影响腹地的空间分异显著。③ 不同城市群中心城市2h出行交通圈衔接联系水平差异显著,表现出多元的圈层叠加的经济联系格局。④ 高密度高速公路路网在提高城市群中心城市2h出行交通圈衔接联系水平中发挥重要作用,按衔接联系模式特征可将各城市群总结为多中心网络型、多中心组团型与双中心轴辐型。

<p>Based on the integrated transport network in 1986, 1994 and 2005, choosing weighted mean travel time as the indicator, the temporal and spatial evolution of integrated transport network and its accessibility are elaborated, and some conclusions are drawn as follows. (1) The speedy development of integrated transport network results in the continual improvement of accessibility, which is faster in the second period (1994-2005) than that in the first period (1986-1994). The optimal region of integrated accessibility is Shanghai and the zone along the Taihu Lake in three time section. The sub-optimal region of integrated accessibility was&ldquo;>- shaped&rdquo; that consisted of the zone along the Shanghai-Nanjing route and the Shanghai-Hangzhou route in 1986 and 1994, but it had the &ldquo;Z-shaped&rdquo; pattern that consisted of the zone along the Shanghai-Nanjing route, the Yangtze River and the Shanghai-Hangzhou route, and the Hangzhou-Ningbo route. (2) The benefits from the improvement of accessibility are different among the nodes. The changing extent of weighted mean travel time is related to the initial value, and the nodes with high initial value decrease more. The changing rate is higher in the central region than that in the north and south regions. Both the changing extent and the changing rate have different patterns in the different periods. (3) Shanghai has the best in integrated accessibility, followed by Jiangsu provinces, and Zhejiang province is the worst, but the dominant position of Shanghai is weakening, and the gap between Jiangsu and Zhejiang is narrowing. (4) The standard deviation of integrated accessibility coefficient decreases in the research period, which shows that the integrated transport network in the Yangtze River Delta is improving, but there are different developmental processes among various transport modes.</p>

以1986、1994、2005年为时间断面,加权平均旅行时间为指标,长三角地区20世纪80年代以来综合交通网络及其可达性的时空演化呈现如下特征:①综合交通网络的快速发展带来了综合交通可达性的不断提升,且第二阶段(1994-2005)发展速度明显快于第一阶段(1986-1994);三时间断面上海及环太湖地区均为可达性最优区域,1986及1994年可达性较优区域大致由沪宁沿线和沪杭沿线构成&ldquo;>&rdquo;形,而2005则大致由沪宁沿线(含沿江地区)、沪杭沿线及杭甬沿线构成&ldquo;Z&rdquo;形;②可达性提升中节点获益具有明显区域差异,加权平均旅行时间初始值越高的节点其值下降幅度越大,加权平均旅行时间的变化率中部地区低于南北边缘地区,但变化值及变化率在不同阶段均呈现不同特征;③从分省市角度,上海可达性最优,江苏板块次之,浙江板块较差,但上海的优势地位逐步下降,浙江板块与江苏板块间的差距正不断缩小;④综合交通可达性系数标准方差逐步下降,表明长三角地区综合交通网络发育日益成熟,但不同交通方式具有不同发展特征.

High-speed rail as the infrastructure for material and information exchange is important channels in urban agglomerations that connect urban centers and facilitate urban expansion, and urban agglomeration is a greater metropolitan area whose internal separation is reduced by high-speed rail system. This study used passenger flow data of 380 sites in the Yangtze River Delta high-speed railway system to construct a 20 by 20 matrix for examining connections between cities in the Yangtze River Delta Urban Agglomeration and its spatial structure. The results show that: (1) The density of network connection between the core cities in the Yangtze River Delta—Shanghai, Nanjing, Hangzhou, and Ningbo—is higher than between other cities; (2) Connections between the core cities of the Yangtze River Delta and cities along major transportation axes, such as Shanghai to Zhenjiang and Jiaxing, Nanjing to Danyang and Huzhou, and Suzhou to Changzhou and Kunshan, have been strong; (3) In terms of "spatial flow" stratification, the first level city network mainly consists of Shanghai-Suzhou-Wuxi-Changzhou and cites along the transportation routes between these cities; the second level city network is mainly composed of Shanghai and Ningbo and cities along the route; the third level city network is mainly composed of Shanghai-Hangzhou-Ningbo and cities along the transportation routes between them; the fourth level city network is mainly composed of Shanghai Jinhua and Yiwu and cities along the route.

高铁作为城市群内部物质与信息交流的基础设施,是城市扩展和城市间相互联系的重要通道,而城市群则是被高铁系统压缩了空间的众多城市空间。本文通过采集长三角城市群380个高速铁路客运数据建构20×20的矩阵,建立了基于高铁客流的长三角城市群城市间联系的矩阵,并在此基础上对长三角城市群内外空间结构进行深入分析。结果表明：①长三角城市群核心城市上海、南京、杭州、宁波间城市网络联系密度高于其他廊道城市间联系;②长三角城市群核心城市向外延伸的轴线联系加强,主要表现为上海与镇江、嘉兴,南京与丹阳、湖州,苏州与常州、昆山等城市间联系紧凑;③在城市群“空间流”分层方面：第一层级主要分布在长三角地区“沪—苏—锡—常”及其沿线;第二层级城市网络主要由“沪—宁”及其沿线路线构成;第三层级城市网络主要由“沪—杭—甬”及其沿线路线构成;第四层级城市网络主要由上海—金华—义乌及其沿线路线构成。

In the perspective of space of flows, the passenger flow of high-speed rail has become an important representation of functional linkage between the city-regions. Based on the interviews and questionnaires from the passengers of high-speed rail of Beijing and Tianjin, this paper analyzes the intercity space of flows and the spatial integration indicated by the individual micro behavior choice. The findings include: (1) Both of the metropolitan areas of Beijing and Tianjin are the dense areas of intercity passenger flow while suburban counties and districts are the sparse areas, which indicates the spatial polarization of HSR in the aspect of passengers' characteristics; The central city of Beijing-Tianjin is the dominant spatial association, while Beijing-Tanggu, Beijing-Wuqing and Tianjin-Wuqing corridors are the secondary spatial association axes, which presents a hub-and-spoke pattern. (2) Leisure activities, such as tourism, shopping, enhance the cross-city flows. Although intercity high-speed rail reduces the temporal and spatial distance to a certain extent, the effects on changing place of housing or work to another city are not obvious. (3) The frequency of cross-city activities is not very high, commuters across cities generally take 7 days as a cycle; Currently, passenger flows of intercity by HSR are mainly business travel and leisure tourism, which reflects HSR as the material foundation for the spaces of flows; the respondents who take the HSR are mostly male, business people with high education and prospective occupation, and the business travelers who have a higher cross-city frequency are more sensitive to travel time, which demonstrates the intercity space of flow has represented some of the elite space characteristics. (4) There is spatial asymmetry in the cross-city space of flow between Beijing and Tianjin, which could be found from the uneven distribution of O-D passenger flows, the differences on the proportion of the business travel flows and the unbalanced function linkage directions.

高速铁路作为一种新型的交通方式,其快速发展将会带来交通运输史上一次重大的飞跃,且其对区域空间结构、人口流动、经济联系和土地利用等的影响也越来越成为人们关注的焦点。在中国区域经济一体化进程不断加快的背景下,研究高速铁路对城市空间相互作用强度的影响,对加强区域间经济联系、促进区域经济发展和地域空间组织模式的重构具有重要意义。本文基于GIS网络分析工具,构建时间成本矩阵,研究中国333个地级行政单元和4个直辖市对外经济联系总量和城市对间经济联系强度的空间分布特征,构建无高铁、高铁现状和规划高铁三种情景,并对三种情景进行模拟与探讨。结果显示：① 城市空间相互作用呈现出明显的地带性和&#x0201c;廊道效应&#x0201d;,反映了高速交通在重塑区域空间结构中的作用;② 高速铁路建设提升了城市对外经济联系强度总量,且逐渐从追求&#x0201c;效率&#x0201d;转向&#x0201c;公平性&#x0201d;;③ 高速铁路建设缩小了全国城市对外经济联系总量的差异,但却扩大了城市对间经济联系强度的差异;④ 三大城市群成为城市对外经济总量绝对获益量最大的地区,而其毗邻的中小城市成为提升速率最大的城市。

East Asia plays an increasingly important role in the world economy in a line with the development of economic integration and accelerated globalization. As one of the influencing factors of economic integration and regional development, HSR will largely influence the regional development, regional structure, commuting, and regional integration. In this paper, we take the high-speed rail in East Asia as a case to explore the evolution of HSR and its impacts on transport circle and accessibility of cities. Results indicate that the evolution of HSR in East Asia firstly follows the "core cities - core cities" mode and then forms a whole network spatially; HSR network has higher service market in population and GDP than in landuse, and the service markets of HSR network in 2012 are mainly located in the eastern and central regions of China, Japan and South Korea, and those of planned HSR network expand to western China and Japan, south part of South Korea; the 1-h transport circle of core cities in East Asia presents a continuous trend along trunk HSR lines, and the 2-h transport circle has formed continuous egions in the Yangtze River Delta, Pearl River Delta, Tokyo, Seoul or along trunk HSR lines, while the court of weighted shortest travel time of cities in China's mainland,Japan and South Korea presents the "core- peripheral structure", taking Zhengzhou in Henan province, Tokyo and Seoul as the core cities; as the development of HSR, the cities located along the trunk HSR lines have a large increase in accessibility, which shows the "corridor effects".

经济全球化和区域一体化进程的不断推进，促使东亚在世界经济中的地位不断提升。高速铁路作为促进经济一体化和区域发展的重要手段和基础，其快速发展势必会对东亚地区的区域发展、空间结构、人口流动和一体化产生重大影响。在分析东亚高速铁路网络发展历程及服务水平的基础上，评价与对比了高速铁路建设对城市交通圈和可达性的影响，及一体化高速铁路潜在的空间效应，以期为东亚一体化高速铁路构建提供指导。结果表明：东亚高速铁路网络扩张整体上呈现出“核心—核心”到网络化的发展历程；高速铁路网络在中国东中部、日本和韩国等地区具有较高的人口和产业服务水平，但国土面积覆盖率相对较低；高速铁路的建设促使核心城市交通圈格局不断扩展与强化，可实现当日往返城市对数量明显增加，主要分布在中国长三角、珠三角，日本东京和韩国首尔周边；中国大陆、日本和韩国的加权平均旅行时间分别呈现出以郑州、东京和首尔为中心的“核心—边缘”结构，且圈层结构逐渐向高速铁路沿线延伸；高速铁路的建设促使城市人口服务水平和可达性的空间格局均呈现出明显的“廊道效应”。

High-speed railway and highway are the important components of land transportation and play an important supporting role in the development and integration of the urban agglomerations. At the urban agglomeration level, this article takes high-speed trains and inter-city coaches as the representatives of the two modes, and compares the characteristics of the two networks with the network analysis method. The results show that: 1) The frequency of high-speed trains is generally higher between urban agglomerations, and the frequency of inter-city coaches is mainly concentrated in the city-pairs in urban agglomerations; 2) The inter-city coach network are more mature and complex in many urban agglomerations and have higher values of the network characteristic indicators than high-speed trains. 3) The development of the two modes of transportation varies greatly in different urban agglomerations. The two networks in the Yangtze River Delta and the Pearl River Delta are relatively mature and developed. The inter-city coach network connectivity in the Beijing-Tianjin-Hebei and Chengdu-Chongqing urban agglomerations is obviously superior to that of the high-speed train network. 4) The high-speed train network is with axis structure, while the inter-city coach network shows the ‘core-periphery’ structure. In the specific urban agglomeration, the two networks’ structures hold differences.

基于城市群尺度，以高铁列车和长途汽车作为2种交通方式代表，结合网络分析方法对比2种方式的联系格局和结构属性等。研究发现：① 高铁列车在城市群之间的运输频次普遍较高，长途汽车的频次主要集中于城市群内部的运输线路；② 各城市群的长途汽车网络已拥有一定规模，网络的成环率、结合度和连接率普遍高于高铁列车网络；③ 2种交通方式在不同城市群的发展差异较大，长三角和珠三角等城市群的2种网络都较为成熟发达，京津冀和成渝等城市群的长途汽车网络连通性明显优于高铁，北部湾等城市群的2种网络都有较大的发展空间；④ 高铁列车网络具有轴线结构特征，长途汽车则呈“核心?边缘”的网络结构，在具体城市群中两种网络结构又具有一定差异性。

Urban agglomeration refers to a highly integrated city and town group. It comes into being with the development of industrialization and urbanization to the advanced stage. The formation and development of urban agglomeration is a long natural process, which is transformed from competition to cooperation. China is in a new stage of urbanization transition, and has entered a new era of leading the global urban agglomeration development in the 21st century. The research and experience model of China's urban agglomeration has been accepted by global urban agglomeration construction as reference. In this paper, the natural law of urban agglomeration is proposed, including developmental gradual law, multi-scale transmission law of space intensive utilization, the combination law of spatial crystal structure, the natural growth of the breeding tree, and the gradient upgrade law of sustainable development. Following these laws, Chinese geographers have made great contributions to the research and development of China's urban agglomerations, which focuses on academic theory, technical method, decision support and planning practice. We developed and scientifically defined the concept of urban agglomeration, and first adopted the identification standard of urban agglomeration space. We established the spatial intensive development and layout simulation decision support technology chain in urban agglomeration, and developed related software chain. We laid out the new pattern of 5+9+6 in the spatial organization of China's urban agglomerations, and formulated the first China's urban agglomeration planning technical regulation. We completed the development plan of most urban agglomerations in China, which has become an important basis for decision-making at the national level. In the future, geographers will play a growing role and shoulder the responsibility in the development of Chinese urban agglomerations. We should combine qualitative and quantitative methods, and use big data and intelligent decision support technology to solve a series of problems in the development of this cause. Only in this way can Chinese geographers make greater contributions to the development of urban agglomerations.

城市群是国家工业化和城镇化发展到高级阶段的产物,是高度一体化和同城化的城市群体,城市群形成发育过程是一个各城市之间由竞争变为竞合的漫长自然过程,遵循自然发展规律。中国正处在新型城镇化转型发展的新阶段,已进入21世纪引领全球城市群发展的新时代,中国城市群研究与建设的经验模式正在被全球城市群建设所效仿和借鉴。本文从理论上梳理并提出了城市群形成发育遵循的自然规律,包括城市群形成发育的阶段性规律、城市群多尺度空间集约利用传导规律、城市群空间晶体结构组合规律、城市群自然生长的育树成林规律和城市群可持续发展的梯度爬升规律。地理学家遵循这些发展规律,从学术理论、技术方法、决策支持和规划实践等方面为中国城市群的研究和发展做出了不可替代的重大贡献,主要包括提出并科学界定了城市群概念,提出了城市群空间范围的识别标准,创建了城市群空间集约拓展与布局仿真决策支持技术链,研制了城市群空间集约拓展与布局仿真决策支持系统软件链,提出了中国城市群空间组织的“5+9+6”新格局,研制出国内第一部《城市群规划技术规程》,编制完成了全国多数城市群发展规划,转化为国家决策的重要依据。未来中国城市群的发展与研究中,地理学家发挥作用的空间越来越大,地理学家肩负着不可推卸的责任使命,应责无旁贷地采用定性与定量相结合的研究方法,引用大数据、智能决策支持技术等新手段解决城市群发展面临的一系列问题,一如既往地为城市群发展吸纳众智、献计献策,发挥更大作用,做出更大贡献。

From the perspective of city-transport system, this article applies space syntax to analyze the physical integration of cities. Traditionally, space syntax is mainly applied to urban areas, buildings, and other scales. However, when space syntax is applied to the configuration analysis of urban agglomeration, the change of scale causes changes in spatial perception and human behavioral patterns. Thus, we present a new method of space syntax. This method defines the lane and track between entrance and exit, and city as node, which represents small-scale space. Infrastructure, such as stations, entrances, and exits, are defined as links. The urban agglomeration is thus transformed into a topological network, and then displayed as a bipartite graph of cities and routes. We take the urban agglomerations in the Yangtze River Middle Reaches (YRMR) as the case study area and analyze its spatial configuration from the perspectives of local and integral, interfaces at different scales, gaps, evolution of the dual foreground and background networks, and evolution of the transport networks. The results reveal the way cities integrate with each other and further reveal the multi-scale spatial structure of urban agglomeration.

The multi-level perspective and multi-scalar city network have gradually become the critical pathways to understand spatial interactions and linkages. The road linkages represent distinguished characteristics of spatial dependence and distance decay, which is of great significance in depicting spatial relationships at regional scale. Based on the data of highway passenger flows between prefecture-level administrative units, this paper tries to identify the functional structures and regional impacts of China's city network, and further explores the spatial organization patterns of the existing functional regions, aiming to deepen the understanding of city network structure and provide new cognitive perspectives for the extant research. The empirical results are shown as follows: (1) It is immediately visible that the highway flows are extremely concentrated on the mega-regions of eastern coastal China and major economic zones in central and western China. And city networks based on highway flows demonstrate strong spatial dependence and hierarchical characteristics, which to a large extent has spatial coupling with the distributions of major mega-regions in China. It is a reflection of spatial relationships at regional scale and core-periphery structure. (2) A total of 19 communities that belong to important spatial configurations are identified through community detection algorithm, and we believe that they are urban economic regions within urban China. Their spatial metaphors can be concluded in three aspects. Firstly, many communities have the same boundaries with provincial level administrative units, which reveals that significant administrative region economy still exists in contemporary China. Secondly, trans-provincial linkages can be formed through spatial spillover effects of mega-regions within specific communities. Thirdly, cities located in the marginal areas of provinces and attracted by powerful center cities in neighboring provinces may become increasingly disconnected with their own provinces and be enrolled into communities of neighboring provinces, which make contribution to the formation of the trans-provincial core-periphery structures. (3) Each community, with its distinguished city network system, demonstrates strong spatial dependence and various spatial organization patterns. Regional patterns have emerged with the features of a multi-level, dynamic and networked system. (4) From the morphology perspective, the spatial pattern of regional city networks can be basically divided into monocentric structure, dual-nuclei structure, polycentric structure and low-level equilibration structure, with the monocentric structure as the major type.

多视角和多尺度城市网络逐渐成为认识空间关系的主要途径。公路流数据具有显著的空间依赖性和距离衰减特性,对于刻画区域尺度空间关系具有重要意义。基于全国地级行政单元间的公路客运流,论文尝试刻画中国城市网络功能结构和区域效应,并对其空间组织模式进行特征提取和规律挖掘,以期能够为城市网络研究提供新的方法支撑和认知视角。研究结果表明：① 基于公路流的城市网络空间形态表现出强烈的空间依赖性和层级特征,与中国主要城市群分布存在较大程度的空间耦合,更多体现的是区域尺度的空间关系及核心—外围组合关系;② 通过社区发现算法识别出19个城市经济区,其空间内涵主要包括行政区经济、巨型区域溢出效应和核心—边缘结构等;③ 不同地域系统内城市网络自成体系,表现出显著的空间依赖性和多元的空间组织模式,多层次、流动性和网络化的地域系统格局凸显;④ 从空间形态上看,区域城市网络空间结构大致可划分为单中心结构、双核心结构、多中心结构和低水平均势结构等区域关联形态,并以单中心发育模式为主。

Many networks of interest in the sciences, including social networks, computer networks, and metabolic and regulatory networks, are found to divide naturally into communities or modules. The problem of detecting and characterizing this community structure is one of the outstanding issues in the study of networked systems. One highly effective approach is the optimization of the quality function known as "modularity" over the possible divisions of a network. Here I show that the modularity can be expressed in terms of the eigenvectors of a characteristic matrix for the network, which I call the modularity matrix, and that this expression leads to a spectral algorithm for community detection that returns results of demonstrably higher quality than competing methods in shorter running times. I illustrate the method with applications to several published network data sets.

复杂网络具有社区结构的性质,即社区内节点的连接比社区间的连接更为紧密。目前,具有复杂网络拓扑结构的社区挖掘算法已有很多,但在很多地理空间的复杂网络中节点间的紧密度,不仅与其连接关系有关,同时与它们之间的距离有关。因此,本文提出将节点间的地理距离考虑到社区挖掘的过程中,修改基于模块度增量矩阵的Newman快速算法(简称CNM算法),将1/d_ijⁿ(d为节点i与节点j之间的距离)作为边权,对加权网络进行社区挖掘,从而发现既相互联系紧密又在地理空间上相互接近的社区。最后,本文用国内航线网络作为实例,将算法用于挖掘航线网络中城市的社区结构,得到10个在航线网络中联系紧密且在空间分布上具有一定地域性的城市社区,与我国的主要经济区域分布比较一致。本算法考虑地理相关性和连接紧密性,较好地识别出空间网络的社区结构。

Urban agglomeration is an important space carrier to promote new urbanization, and the spatial structure is the spatial reflection of the degree, stage and process of urban agglomeration. From the 3 aspects of urban agglomeration benefit, distance benefit and spatial connection benefit, this article use ArcGIS and urban interaction intensity model to compare the spatial structure benefits of the Changsha-Zhuzhou-Xiangtan urban agglomeration and Dongting Lake urban agglomeration in the development stage. The results show that Dongting Lake urban agglomeration has a comparative advantage in external scale including the population scale, land area and the city quantity. However, the compactness of urban agglomerations is low, the advantages of urban scale structure are not obvious enough and the spatial connection between important cities is not tight enough. It shows a more obvious "big and scattered" characteristics, and the quality of development and the degree of development are not good. Changsha-Zhuzhou-Xiangtan urban agglomeration is relatively small in terms of number of cities, population size and land use, but its compactness and scale benefits are relatively high, and the scale structure has a relatively high degree of dominance. On this basis, aiming at maximizing the efficiency of urban agglomeration spatial structure, the spatial structure system of “one heart, two circles and three axes” and “1+5” urban agglomeration with Changsha as the center city is proposed, which to provide references for the optimization and development of the urban agglomeration spatial structure.

从城市群规模效益、距离效益和空间联系效益3个方面出发,运用ArcGIS和城市相互作用强度模型对长株潭城市群和环洞庭湖城市群空间结构效益进行评价比较分析。结果表明：环洞庭湖城市群在外在规模上具有相对优势,具体表现为人口规模、空间规模以及城市数量较大,但城市群的紧凑度不高,城市规模等级结构优势不够明显,空间可达性较差,重要城市之间的空间联系不够紧密,呈现“大而散”的特征;相对而言,长株潭城市群城市数量、人口规模及用地较小,但其紧凑度及规模效益较高,城市规模等级结构优势度相对较高,可达性较好,重要城市之间的空间联系较为紧密。在此基础上,以实现城市群空间结构效益最大化为目标,构建了以长沙为中心城市的“一心两圈三轴”结构体系。