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1.
The connectedness between cities has become one of the most widely discussed topics in urban and regional research in the mobile and big data era. One problem identified is the asymmetric city connectivity, partially due to data availability. We present a data-driven approach based on location and toponym(place name) extracted from social media data, to assess the asymmetric connectivity between cities. The assumption is that a higher frequency of occurrences of the name of city i in posts located in city j would imply that the city i is more influential than other cities upon city j. In addition, we’ve developed a group of measurements such as the relatedness index, impact index, link strength index, dependence index, and structure similar index to characterize such interactions. This framework of connectivity measurements can also be used to support smart planning taking into account the evolving interplay among cities. The space-time structure of urban systems in China is examined as the case study.  相似文献   

2.
Evolution and spatial patterns of spheres of urban influence in China   总被引：2，自引：1，他引：1  
This article presents the findings of a study of the spheres of urban influence with regard to all cities in China（not including Hong Kong,Macau and Taiwan Province of China）in the years 1990,2000 and 2009.An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations.Such urban agglomerations are characterized by high density population and a developed economy,which are also considered as the national competition unit.This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution.Some basic characteristics of urban agglomerations are outlined,including the number of cities,the size of cities and the functions of urban centers.These characteristics are examined by using statistical methods and Geographic Information System（GIS）.The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly.It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors.  相似文献   

3.
In metropolitan regions, the change in the strength of＂flows＂ between a core city and surrounding cities reflects the range of the core city＇s influence, while the gravity between core city and other cities reflects the strength of potential relation between them. This article firstly attempts to delimit the boundary of metropolitan regions with the two dimensions measure combining ＂flows＂ and gravitation. The former is measured through the flow of people between the core city and surrounding cities, and the latter is measured through both population and gross domestic products （GDP） of the core city and surrounding cities. The hierarchy of the cities within a metropolitan region is classified in order to emphasize the roles of the cities belonging to the metropolitan regions, different from the general way through population scale and administrative level, and is typical in China. This paper uses the Shanghai metropolitan region as a research case, determining boundary of this metropolitan region clearly and classifying hierarchy of the cities within the region. The final results are significantly different to previous work, even overthrowing the traditional system of urban hierarchy partly. It is helpful to highlight the function of cities in organizing the regional economy, the level structure of metropolitan regions, and each city＇s relative importance in a metropolitan region, which can be taken as scientific basis for planning integrated regions or urban systems.  相似文献   

4.
This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which business services firms play the crucial role in city network formation, information is gathered about the presence of global service firms in cities. This information is converted into data to provide the′service value′of a city for a firm′s provision of corporate services in a 526(cities)×175(firms) matrix. These data are then used as the input to the interlocking network model in order to measure cities′connectivity and its predominant geographical orientation. Here we focus on the position of some key Chinese cities in this regard, and discuss and interpret results in the context of the urban dimensions of the′opening up′of the Chinese economy.  相似文献   

5.
The quality dimension of the urban living space was addressed much earlier abroad; nevertheless, it has not been studied in the Chinese academia up to date, as evidenced by the limited research literature. Through recourse to Rich BOYER‘s nine-factor theory, this study attempted to evaluate and rank 31 target cities, by using the data from the China Statistical Yearbook 2002. Our research results show that the quality of a city‘s living space is in positive correlation with its size, and that there will be changing demands for the quality of the urban living space as a result of future social, economic, sci-tech, cultural and educational developments, combined with the improvement of the overall quality of urban residents. Previous research was focused on the quality of food, housing, education, transportation and entertainment. However, with the development of the knowledge-economy, such factors as information accessibility, green environment, and air quality, will be major considerations in the quality evaluation of the urban living space.  相似文献   

6.
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.  相似文献   

7.
Against the backdrop of the sizable economic growth of China in recent years, this paper uses the most recent data gathering of the Globalization and World Cities(Ga WC) research network to update and supplement earlier research on the shifting global connectivity of Chinese cities. The update consists of an evaluation of the connectivity of Chinese cities in 2016, the supplement of an analysis of the changing position of Chinese cities in the world city network between 2010 and 2016. To this end, we build on a specification of the world city network as an ‘interlocking network' in which producer services firms play the crucial role in city network formation. Information about the presence of leading producer services firms in cities in 2010 and 2016 is used as the input to a bipartite network projection algorithm in order to measure cities' network connectivity. The first set of results discusses the geographies of urban connectivity in the world city network in 2016. The second set of results discusses standardized measures of change to reveal the major dimensions of the transformations between 2010 and 2016. We find that, with the exception of Hong Kong, Macau and Kaohsiung of Taiwan, all Chinese cities record connectivity gains. This wholesale rise in connectivity is nonetheless geographically uneven, with above all Beijing, Chengdu/Chongqing and Changsha/Wuhan becoming more connected. We conclude that the wholesale rise of Chinese cities in the world city network and their changing trajectories in the post-crisis era are embedded in shifting external and internal political economies.  相似文献   

8.
Currently domestic researches on urban imago space concentrate in a few cities that lie in the advanced region, such as Beijing, Guangzhou, Wuhan, etc., but in so far as those cities that lie in the northwest inland region, the research of this aspect is still few. In order to supplement a special example to the urban imago space theory and to validate former theory, this article studied the Lanzhou urban imago space. During the course of researching, authors adopted some investigating methods, such as visiting on the spot, photograph identification method and sketch man identification method etc. Using investigated data, this paper made an elementary research on urban imago space of Lanzhou, which is a typical valley city in the western China. The result of study indicated that the urban imago space of Lanzhou takes Xiguan Cross as its center (Lanzhou involves four districts of Chengguan, Qilihe, Arming and Xigu). In the process of recognition of urban imago space, the Huanghe (Yellow) River and mountains beside the city are the dominant factors and the main nodes of cognition. So the urban imago space of Lanzhou is quite different from that of plain cities. Interviewee did well in the spatial structure map, which was made up of mountainous land, river and main trunk roads, the group structure took profound impression on people.  相似文献   

9.
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.  相似文献   

10.
China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires of 11 villages in 2 counties and Tobit model,this paper analyzes the geographical differences and influencing factors of energy consumption for non-production purposes of rural households living in different terrain conditions.This research finds that:(1) Coal takes up the main part of energy consumption in valley areas and coal consumption is mainly affected by per capita cultivated land area,household income,proportion of rural household energy expenditure in total expenditure,coal price,and family population size.Firewood takes up the main part of energy consumption in high mountain areas and firewood consumption is mainly affected by per capita firewood forest area,distance to purchase coal,household income,electricity price,and coal price.(2) Only when the distance is greater than 20 kilometers,that is the average distance of rural households living in middle mountain areas(1,600m~1,800m) to purchase coal,the transportation condition has a significant impact on coal consumption.(3) In high mountain areas,prices of coal and electricity are the main factors influencing energy consumption choice of rural households.Too high prices of coal and electricity would to some extent lead rural households to choose firewood as the main energy consumption type.Compared to coal,rural households prefer to choose electricity.  相似文献   

11.
近年来大数据在交通分析中被广泛关注,但目前多以可视化展示和现象空间分析描述为主,缺乏基于大数据的交通数量模型和模拟预测研究,成为大数据技术在交通规划中应用的主要技术障碍。本文基于交通与土地利用之间的交互作用关系,构建区位空间依赖因子（(Location-space Dependence Indicator, LSDI）,对传统重力模型进行改进,提出大数据城市通勤分布模型。以北京市为例,采用某运营商2017年9月的手机信令大数据,进行模型的应用和校验。模拟结果显示,在出行产生预测中,通勤人口与常住人口表现出良好的线性关系;在出行分布预测中,基于区位空间依赖因子的修正重力模型综合表现最优,在通勤OD分布中实现了低估现象的优化,在OD数量发生率中拟合优度达到0.85。本研究为大数据城市交通预测模型研发提供了新的技术方法,对于推动大数据在交通规划中的应用具有一定价值。  相似文献   

12.
新疆绿洲城镇对称图谱及其生态经济模式分析   总被引：2，自引：0，他引：2  
天山南北的绿洲城镇以天山为轴对称,分布图案似一副向西张开的弓箭。在局部区域绿洲分布呈线形、弧形、扇形和放射形模式。绿洲经济以水土资源和矿产资源为依赖,中心城市的形成不以城市配位数和平均距离的大小为关键条件。县级中心城镇人口低于10万,平均配位数为3.50,平均距离144km;地市级中心城市人口10～60万,平均配位数4.25,平均距离450km;西部地区百万人口大城市的平均距离约2000km。绿洲人口持续增长,人口密度233人/km2,超过德国人口密度230人/km2。受控于景观带谱对称格局,生态保护政策将使绿洲转向岛国经济模式,发展经济必须跨越自然空间。工业化和城市化是绿洲发展的必然途径,以发展中小城市为主线。距离省府乌鲁木齐2000km以内的配位经济中心难以带动新疆经济跨越式发展,经济跨越式发展的动力模式,不是城市等级配位分布网络的稳定模式,而是经济差级配位模式。乌鲁木齐处于欧亚大陆新丝绸之路欧亚大陆桥中点处经济地理线形谷地位置。欧亚大陆东部与西部沿海经济中心可以作为与新疆经济合作的优先目标。  相似文献   

13.
Assessment of debris flow hazards is important for developing measures to mitigate the loss of life and property and to minimize environmental damage. Two modified uncertainty models, Set Pair Analysis （SPA） and modified Set Pair Analysis （mSPA）, were suggested to assess the regional debris flow hazard. A ease study was conducted in seven towns of the Beichuan county, Sichuan Province, China, to test and compare the application of these two models in debris flow hazard assessment. The results showed that mSPA only can fit for value-variables, but not for non value-variable assessment indexes, Furthermore, as for a given assessment index xi, mSPA only considers two cases, namely, when grade value increases with xi and when grade value decreases with xi. Thus, mSPA can not be used for debris flow hazard assessment but SPA is credible for the assessment because there are no limitations when using SPA model to assess the debris flow hazard. Therefore, in this study SPA is proposed for assessing debris flow hazard.  相似文献   

14.
Rapid urbanization results in the conversion of natural soil to urban soil,and consequently,the storage and density of the soil carbon pools change.Taking Chongqing Municipality of China as a study case,this investigation attempts to better understand soil carbon pools in hilly cities.First,the vegetated areas in the study area were derived from QuickBird images.Then,topsoil data from 220 soil samples(0-20 cm) in the vegetated areas were collected and their soil organic carbon(SOC) densities were analyzed.Using the Kriging interpolation method,the spatial pattern of SOC was estimated.The results show that the SOC density exhibited high spatial variability in the urban topsoil of Chongqing.First,the SOC density in topsoil decreased according to slope in the order 2°-6° < 25°-90° < 0°-2° < 6°-15° < 15°-25°.Second,the newly developed areas during 2001-2010 had a lower SOC density than the areas built before 1988.Third,urban parks and gardens had a higher SOC density in topsoil,residential green land followed,and scattered street green land ranked last.For hilly cities,the variability of terrain affects the distribution of SOC.The Kriging results indicate that Kriging method combining slope with SOC density produced a high level of accuracy.The Kriging results show that the SOC density to the north of the Jialing River was higher than the south.The vegetated areas were estimated to amount to 73.5 km2 across the study area with an SOC storage of 0.192 Tg and an average density of 2.61 kg/m2.  相似文献   

15.
Road network is a critical component of public infrastructure,and the supporting system of social and economic development.Based on a modified kernel density estimate(KDE)algorithm,this study evaluated the road service capacity provided by a road network composed of multi-level roads(i.e.national,provincial,county and rural roads),by taking account of the differences of effect extent and intensity for roads of different levels.Summarized at town scale,the population burden and the annual rural economic income of unit road service capacity were used as the surrogates of social and economic demands for road service.This method was applied to the road network of the Three Parallel River Region,the northwestern Yunnan Province,China to evaluate the development of road network in this region.In results,the total road length of this region in 2005 was 3.70×104km,and the length ratio between national,provincial,county and rural roads was 1∶2∶8∶47.From 1989 to 2005,the regional road service capacity increased by 13.1%,of which the contributions from the national,provincial,county and rural roads were 11.1%,19.4%,22.6%,and 67.8%,respectively,revealing the effect of′All Village Accessible′policy of road development in the mountainous regions in the last decade.The spatial patterns of population burden and economic requirement of unit road service suggested that the areas farther away from the national and provincial roads have higher road development priority(RDP).Based on the modified KDE model and the framework of RDP evaluation,this study provided a useful approach for developing an optimal plan of road development at regional scale.  相似文献   

16.
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.  相似文献   

17.
中心城市腹地合理地划分对区域的资源整合、协调发展起到关键性的作用。本文立足于加权Voronoi图,将城市的中心性强度及综合交通可达性作为权重引入断裂点模型中,修正了断裂点模型中的城市人口规模,构建了加权Voronoi图城市腹地界定新模型;并以成渝经济圈36个中心城市为例,对模型进行验证。研究表明,成渝经济圈各中心城市腹地与行政区范围吻合度较差。根据腹地与行政区范围大小的比值将城市划分为3类:比值大于100%的城市具有良好的适合腹地向外扩展的条件,对周边城市的发展有较大影响;比值在60%~100%之间的城市对周边城市的发展起到一定作用;比值小于60%的城市则说明周边城市的影响力远远大于本市。而四川省的成都市和重庆市的主城作为区域实力最强的城市,其腹地范围并不是最大的,这表明城市腹地的范围及大小主要由中心城市的综合实力和周边城市的综合实力共同决定。这是对成渝经济圈各城市腹地的重新界定,对成渝经济圈城市规划有一定参考意义。  相似文献   

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