共查询到20条相似文献，搜索用时 453 毫秒
1.
What is a hilly city, and which cities are hilliest? This study outlines a basket of methods for quantifying the differential hilliness of U.S. cities. We rank the 100 largest cities in the contiguous United States, using a selection of eight methods to evaluate their comparative hilliness. We then reflect on how four key “modes of encounter” with terrain shape human perceptions of urban hilliness: visual, pedestrian, automotive, and imagined/conceptual. Varying priorities among these different modes of encounter shape which of our indices may best correlate with lay understandings of urban hilliness or particular policy problems. We conclude with implications of this work for contemporary geographic scholarship and suggestions for further research, particularly with regard to the political and economic effects of hilliness. 相似文献
2.
Ugo Rossi 《Urban geography》2018,39(9):1425-1430
Generalizing the recent experience of the United States, the common wisdom associates today’s ‘populist explosion’ with a deepening urban-rural divide, in which small towns and rural regions are seen as reservoirs of populist anger while large cities in the most prosperous areas are portrayed as strongholds of multicultural coexistence and liberal democracy. In challenging this representation, this paper underlines the ‘urban roots’ of today’s populist phenomenon in Western societies, using Italy as illustrative evidence. It is argued that cities – far from being pacified enclaves of happiness and democracy – are central to the contradictions of contemporary societies and their degenerations, reflecting an ambivalent relationship with the nation-state: potential sites of post-national democracy, on the one hand, but also spaces contributing to the current populist-white-revanchist wave sweeping Western societies, on the other hand. In doing so, the paper shows how the intersected housing and refugee crises have fomented impulses of ethnic-majority revanchism within Italy’s cities and towns in a context of late neoliberalism. 相似文献
3.
基于城市夜间灯光数据的中美两国城市位序规模分布对比 总被引：1，自引：0，他引：1
工业革命以来,人类开启了大规模的城市化进程。城市随着交通和通讯技术的发展不断突破原有的规模限制,城市规模不断变大。以人口为指标的城市规模分布服从齐普夫法则。不同城市化发展阶段,其城市位序规模分布存在差异。城市夜间灯光数据一般可用来衡量城市的经济活动、建成区面积、人口密度、发展水平等。本文以同源的城市夜间灯光数据代表城市规模,在国家尺度和省州尺度研究中美两国城市规模位序分布,并比较其异同。研究表明,在国家尺度,2013-2016年间,中美两国城市规模均变得集聚,而中国城市规模分布比美国更为分散,齐普夫指数相差约0.1。在省州尺度,不同省州的城市规模分布存在差异,中国和美国分别有44%和84%的省份或州的齐普夫指数大于1,中国城市规模分布分散型省份占一半以上,而美国的集中型的州则占有84%,总体而言,中国城市的规模分布更为分散。中美两国高位序城市实际值远低于拟合值,理论上仍然具备很大的发展潜力。中国高位序城市需要进一步提高城市经济活动的聚集程度,使得城市规模体系更趋完善与成熟。 相似文献
4.
中美城际科技创新合作网络的空间演化 总被引：3，自引：1，他引：2
知识与技术是科技创新的重要表征,中美科技竞争与合作成为世界经济地理研究的热点和前沿。本文集成数据挖掘、知识计量、社会网络和GIS空间分析方法,从论文合著、专利合作及专利交易三个维度,刻画了中美科技创新合作网络的空间演化规律：（1）中美参与双边科技创新合作的城市数量持续增长,但美国城市仍占据主导位置;（2）参与科技合作的节点以高校科研院所集中、科技创新能力突出的城市为主,且保持时间惯性和空间粘性;（3）论文和专利等知识合作城市的空间分布相对分散,而专利技术转移则具显著空间集聚性,高度集中于少数科技创新中心;（4）中国科技创新合作枢纽城市高度集中于东南部沿海和和港澳地区,而美国则呈明显的接触扩散特征;（5）中美城市科技创新合作呈现网络化态势,论文合作网络由三核点对式主导向四核轴—辐式演化,专利合作联系范围日益分散,高度依赖个别枢纽城市;（6）中国对美国的专利技术依赖度过大且持续加深,而美国对中国则持续减弱。 相似文献
5.
Beyond Edge City: Office Geography in the New Metropolis 总被引：1，自引：0，他引：1
《Urban geography》2013,34(7):726-755
6.
Use of the allometric function to estimate the number of inhabitants of urban areas, given knowledge of their land areas obtained through satellite photographs, rests as much on the stability of this function over time as on its goodness of fit to a cross section of cities at a single point in time. Using urban land and population data for four countries, the United States, Japan, Sweden, and Norway, this paper demonstrates that the function is not generally stable but rather has been subject to rapid upward shifts over the past 10 to 20 years. 相似文献
7.
20 世纪美国城市体系的演变及其对中国的启示 总被引：3，自引：1，他引：2
在快速城市化过程中,在规模不等的城市中城市人口将如何分布？这是制订中国社会经济发展战略必须考虑的一个重大基础问题。美国是世界上最大的发达经济体,城市体系成熟,100 年前的城市化水平和中国现在相当。研究20 世纪美国城市体系的演化特征,对中国会有所启发。采用美国人口普查数据,运用位序-规模法则等方法,分析了美国城市系统的演变过程。结果显示：在20 世纪前70 年美国城市化处于加速发展的中期阶段,大城市的人口增长明显快于中小城市,城市体系向非均衡化方向发展;20 世纪后30 年,美国城市化进入了稳定发展的后期阶段。与美国不同的是,处于城市化加速发展中期阶段的中国(1985-2000 年),小城市人口增长较快,城市体系趋于均衡。研究认为：未来我国大城市的人口集聚有较大潜力。 相似文献
8.
《The Professional geographer》2013,65(4):365-370
Use of the allometric function to estimate the number of inhabitants of urban areas, given knowledge of their land areas obtained through satellite photographs, rests as much on the stability of this function over time as on its goodness of fit to a cross section of cities at a single point in time. Using urban land and population data for four countries, the United States, Japan, Sweden, and Norway, this paper demonstrates that the function is not generally stable but rather has been subject to rapid upward shifts over the past 10 to 20 years. 相似文献
9.
《The Professional geographer》2013,65(4):367-368
Mounting evidence indicates that large, world-class cities have expanded their spatial markets well beyond the regional urban systems in which they are located. This has led many observers to conclude that in the contemporary economy, interdependence, interaction, and connectivity are no longer fundamental characteristics of hierarchical urban systems. Virtually all research, however, deals exclusively with the changing role of large cities, while the spatial markets of medium- and smaller-sized cities comprising an urban system have been ignored. The primary objective of this paper is to investigate whether the spatial markets of medium- and smaller-sized cities in an urban hierarchical system continue to display a systematic relationship with city size, or whether they also reveal the absence of connection, or integration, with the regional system. The analysis uses survey data collected from 480 producer service firms located in an urban hierarchy comprising 15 midwestern cities of the United States. The results indicate that the spatial market of the largest city (Chicago) extends well beyond the Midwest urban hierarchy, while the spatial markets of smaller-sized cities are more integrated within the hierarchical system. 相似文献
10.
城市范围界定与标度律 总被引：5，自引：2，他引：3
标度律作为城市发展的重要规律之一,反映了城市经济活动产值、基础设施数量等要素随城市人口规模的变动情况,在城市研究领域引起了广泛讨论。但由于不同国家的城市统计数据对应的空间范围各不相同,导致标度律系数受城市边界范围选取影响很大。本文通过比较中、美两国统计数据对应的空间范围,并结合普查、城市统计年鉴和遥感数据,计算了不同空间范围对应的标度律系数。结果表明：① 不同空间尺度和数据源得到的标度律系数有较大差异。就空间尺度而言,市辖区比市域范围的数据更符合标度律模型,因为中国城市市域范围内还存在大量的非城市化地区,并不符合标度律模型的适用条件;就数据源而言,遥感数据比城市统计年鉴数据有更好的拟合优度;② 与美国城市相比,中国城市人口集聚带来的经济增长率更高（标度律系数更高）,市辖区人口每增加一倍,经济规模可增加122%,这一数字在美国是111%;而在家庭能源消耗（用水、用电）和土地利用方面,中国城市的效率更低;③ 从中国城市内部对比来看,大城市与中小城市在经济规模、土地利用方面的标度律（集聚效率）明显不同,人口集聚效应带来的大城市经济增长率、工资收入要远高于中小城市;能源消耗方面,中小城市比大城市更有效率。最后,本文还从建立更加有效的统计单元、传统统计数据与大数据结合、模型机制探索3个方面阐述了城市标度律未来可能的研究方向。 相似文献
11.
Mounting evidence indicates that large, world-class cities have expanded their spatial markets well beyond the regional urban systems in which they are located. This has led many observers to conclude that in the contemporary economy, interdependence, interaction, and connectivity are no longer fundamental characteristics of hierarchical urban systems. Virtually all research, however, deals exclusively with the changing role of large cities, while the spatial markets of medium- and smaller-sized cities comprising an urban system have been ignored. The primary objective of this paper is to investigate whether the spatial markets of medium- and smaller-sized cities in an urban hierarchical system continue to display a systematic relationship with city size, or whether they also reveal the absence of connection, or integration, with the regional system. The analysis uses survey data collected from 480 producer service firms located in an urban hierarchy comprising 15 midwestern cities of the United States. The results indicate that the spatial market of the largest city (Chicago) extends well beyond the Midwest urban hierarchy, while the spatial markets of smaller-sized cities are more integrated within the hierarchical system. 相似文献
12.
特大城市空间形态差异对交通网络效率的影响 总被引：4，自引：1，他引：3
以交通网络出行迂回作为交通网络效率分析的切入点,选取形状指数、紧凑度作为空间形态分析指标,对特大城市空间形态布局进行类型划分,并挖掘各城市交通网络效率空间分布差异特征,基于多元回归模型剖析中国各特大城市空间形态布局与交通网络效率之间的影响关系。研究表明：① 5种类型城市交通效率高低分布差异明显,紧凑圆形城市边缘区交通网络效率较低,而非紧凑带形交通效率低的区域多分布于城市核心区,紧凑方形城市交通网络效率高地区分布较为集中,而非紧凑方形交通效率低的地区分布较为分散,紧凑带形城市面积越小则交通效率越高。② 就城市空间布局与交通网络效率影响关系而言,随着城市形状指数的增大,城市交通迂回值未进一步增大,说明城市形态布局接近圆形均匀分布时,其城市交通网络效率较高;随着城市紧凑度值的增加,城市交通迂回程度值亦不断增加,说明城市形态布局程度越紧密,反而其交通网络效率越低,当城市形态布局紧密程度适中时,交通网络效率水平较高。 相似文献
13.
《The Professional geographer》2012,64(1):152-164
The literature on shrinking cities has significantly grown in recent years. Little work, however, has been done toward the development of a shrinking city typology, which could help inform solutions and strategies to address problems associated with population loss. With a focus on central cities, this article identifies 367 shrinking cities within the United States and categorizes them using a geographic information system to identify seven types of shrinking cities in the United States: (1) large shrinking central cities, (2) inner-ring suburbs of shrinking central cities, (3) outer-ring suburbs of shrinking central cities, (4) inner-ring suburbs of growing central cities, (5) outer-ring suburbs of growing central cities, (6) small shrinking central cities in small Metropolitan Statistical Areas, and (7) small shrinking cities in small Micropolitan Statistical Areas. The empirically generated clusters, combined with associated social and demographic information, identify separate but sometimes interrelated shrinking city types and provide a new perspective for addressing the problems faced by U.S. shrinking cities. Key Words: population decline, shrinking cities, typology, urban population. 相似文献
14.
美国城市郊区化及对策对中国城市节约增长的启示 总被引：1，自引：0，他引：1
城市的空间发展中一直同时存在着向心集聚和离心扩散两个过程,郊区化是城市中心区离心扩散力量超过向心集聚力量的一种空间表现形式,能有效缓解大城市因规模扩大而带来的人口密集、交通拥挤等现象;但同时也会产生土地资源浪费、生态环境破坏、阶层分化隔离以及内城衰退等负面影响。美国的城市郊区化现象最为典型,在应对郊区化问题,如怎样有序的建设和管理以及处理好建设和保护的关系等方面积累了丰富的经验。然而,由于土地所有制和城市化阶段的不同,中国与西方发达国家的郊区化呈现出不同特点。中国目前正处于快速城市化时期,由于GDP导向下的城市空间跨越式发展使得一些大城市已出现郊区化现象,导致"外溢—回波"效应突出等问题。通过对中﹑美城市郊区化现象进行比较分析,同时借鉴美国在有效发挥郊区化作用和解决郊区化造成的问题方面的先进经验,并基于城市节约增长的视角,研究如何提高城市空间增长的效率,希望在先进理念、管理技术以及协调政府和市场职能作用方面对城市发展做出有效的把握和引导。 相似文献
15.
Sarah A. Robertson 《The Australian geographer》2020,51(3):307-324
ABSTRACT What role does soil play in sustainable design interventions and can it help to reconfigure human place experiences and human-nature relations in cities? Cities are home to a host of nonhuman actors that are overlooked or under-acknowledged in design and planning practices and in everyday dwelling. Soil is one such under-acknowledged urban inhabitant. In a period where cities and their inhabitants must adapt to the challenges of a changing climate, the paper draws together theory in design, planning and geography and empirical research with designers and residents in Australian cities to re-place soil as mattering in place(making) practices, everyday urban dwelling and urban sustainability transitions. The research contributes to recent work in (post)human geography to discuss ‘soil-planty mattering’, or the active role of soils and their intra-actions with other urban matter in shaping place. Soil-planty mattering is shown to disrupt human place(making), extending cities in material, temporal and spatial ways. In these extensions, the research suggests that soils have particular potential to re-orient human relationships with nonhumans in urban realms. 相似文献
16.
《Urban geography》2013,34(2):95-117
This paper examines changes in the incidence of low-income employment within and across different tiers of the United States urban hierarchy between 1950 and 1990 using data from Public Use Microdata Samples. Theoretical guidance comes from past studies on the relationship between urban hierarchy and income inequality and more recent conceptualizations of global cities. An established urban typology is used to identify the “positions” of 105 metropolitan labor markets that can be tracked over the past four decades. Results show that local rates of low-income employment have varied systematically throughout the urban hierarchy during the post-war era and that rates consistently have remained the lowest within higher order cities and the highest within peripheral manufacturing centers. These findings are repeated among distinct race and gender groups and indicate that the urban hierarchy continues to play a significant role in shaping the size of the local low-income workforce. 相似文献
17.
《Urban geography》2013,34(6):484-519
Post-modern urban theory has problematized the universality of existing models of urban form by focusing on fluidity and complexity in the urban landscape. Urban form is "chaotic," "galactic," and even "random" according to this view. Somewhat lost in this perspective are the emergent urban forms occurring in a wide variety of cities. This paper challenges the universalization of landscape complexity that lies at the core of post-modern urbanism by examining landscape changes in the 10 largest metropolitan areas in the United States. The key findings are that landscape complexity vis the mid-20th century city is overstated—not least because the latter was itself quite complicated—and that the unyielding focus on difference deflects attention away from important processes like inner-city revalorization, inner-suburban devalorization, and outer-suburban valorization that are reshaping very different cities in largely similar ways. 相似文献
18.
本文致力研究创意产业集群与城市政策和效益之间的互动。研究的创意产业行业包括软件、多媒体、电子游戏、时装设计、出版、研究与开发。经验调查研究以多个城市的情况作为基础,这些城市包括美国的波士顿、旧金山、圣迭亚戈、西雅图、奥斯丁、华盛顿特区、爱尔兰的都柏林、东京和印度的班加罗尔。本文关键的研究问题是:什么类型的城市是富有创意的?什么区位因素是必不可少的?创意城市共同采取的政策措施有哪些?文章首先总结了影响地方特定创意产业集群的因素和政策措施;接着深入剖析两个成功的创意城市——波士顿和圣迭亚戈的案例,随后讨论城市各自的某些特征是否使得它们更适合发展某一特定的创意产业。 相似文献
19.
长三角城市网络外部性的空间异质性 总被引：1，自引：1，他引：0
城市网络中是否存在“低端锁定”现象,低等级城市能否从网络中获益,高等级城市是否发挥了辐射带动作用,这些问题关系城市群发展的战略导向,当前仍缺乏深入论证。城市网络外部性是指城市因联系而得到的效益,为回答上述问题提供了理论依据,已成为城市网络研究的新热点。但现有研究主要关注网络外部性的整体特征,忽视区域内城市间的网络外部性差异。本文使用地理加权回归模型将网络外部性测度精确到每个城市,揭示网络外部性的空间异质性特征。研究以长三角地区41个城市为研究对象,按城市汇总企业之间相互投资规模构建城市网络,分析网络联系对城市发展水平的影响,证实了长三角地区存在网络外部性。研究发现：(1)虽然网络外部性未成为主导,但嵌入城市网络已经对江浙沪城市发展起到了积极影响。(2)网络外部性的地域差异较大,江苏省城市的网络外部性普遍强于浙江省,安徽省的网络外部性不强,城市发展仍主要由人、土地和资本的本地集聚决定。(3)长三角地区的网络外部性主要是在上海的辐射带动作用下形成的,3个省会城市南京、合肥、杭州对周边城市的辐射带动作用有限。(4)低等级城市虽未从网络中获得明显的效益,但也未被“低端锁定”,高等级城市没有在周... 相似文献
20.
基于期刊论文的中国地级以上城市知识专业化研究 总被引：3，自引：2，他引：1
将287个地级以上城市（不包括港澳台地区）作为研究对象,以中国知网发布的168个学科领域期刊论文数量为数据来源,对中国地级以上城市知识专业化水平、影响因素及其与经济发展的关系进行了研究。研究发现：① 中国地级以上城市的专业化水平总体偏低,多样化水平较为明显;知识专业化水平西部地区>中部地区>东部地区;地区相对专业化指数随城市行政等级依次升高,即直辖市<副省级城市<省会城市<普通地级市。具有资源优势的城市,其知识专业化领域高度集中在以资源为基础的领域;中小城市的知识专业化领域相对较少,专业化程度高;大中城市知识专业化领域多,多样化趋势明显,但各领域的知识专业化程度相对较低。从城市等级上来看,知识专业化程度表现为五线城市>四线城市>三线城市>二线城市>一线城市。② 知识专业化水平主要受科教经济因素、人才潜力和服务业因素、工业基础因素、人口规模因素四大因素影响。③ 知识专业化与经济发展关系密切,整体呈现倒U形关系;但各区域随发展阶段不同,表现出不同的形式可以分为U形、倒U形、M形和W形4种大类型。 相似文献