DO CENTRAL CITIES AND SUBURBS HAVE SIMILAR DIMENSIONS OF NEED?

This paper examines the proposition that United States suburbs are gradually acquiring many of the traits and problems traditionally associated with inner cities. An analysis of direct and surrogate measures of community development need indicates that in 1970 the average central city had a greater percapita need than the average Chicago suburb. However, the dimensions of need of central cities and suburbs are quite similar. Close associations between minority race, poverty, and female-headed families exist in both central cities and suburbs, as do high residual correlations between population decline, elderly populations, and low levels of crowding.     

Assembling insurgent citizenship: immigrant advocacy struggles in the Washington DC metropolitan area

This article examines the political and spatial registers of struggles against exclusionary local immigration policies and for more welcoming policies in the Washington DC metropolitan area, one of the hotspots for both local anti-immigration policies and immigrant advocacy in the United States. We conceptualize immigrant advocacy not simply as an alliance, but instead as an assemblage that brings together a diverse set of differently positioned actors and nonhuman actants. The assemblage enacts a diverse politics that deploys different forms of activism, while engaging different publics (e.g., religious communities, unions, the larger public sphere in public spaces, etc.) and the state in complex ways. From acting outside the state to engaging in claims-making towards the state, immigrant advocates are making claims and actions that challenge and go beyond dominant conceptions of citizenship rights and liberal democratic politics. The spatial register is similarly diverse. The immigrant advocacy assemblage is confronted with and enacts a different politics of place in central cities and inner- and outer-ring suburbs. Contestations of exclusionary local policies, however, are not simply about a local politics of place. To the contrary, some actors and actants in the assemblage are actively involved in extra-local networking, collaborating across jurisdictional boundaries—between central cities and inner-and outer-ring suburbs within the Washington DC metropolitan area and across the United States. The complexities of these contestations call into question post-political narratives of “proper” politics, underscoring the need for an empirically grounded critical theory of democracy. This article contributes to this task by providing a geographically and historically sensitive analysis of the immigrant advocacy assemblage.     

The Suburbanization of Food Insecurity: An Analysis of Projected Trends in the Atlanta Metropolitan Area

Although general patterns of food insecurity in the United States are known, few studies have attempted to estimate small area food security or account for ongoing socioeconomic changes. Here we address these issues by producing small area estimates of food insecurity in the Atlanta metropolitan area using two methodologies: fixed effects modeling and demographic metabolism. In both cases, we use county-level data from the Current Population Survey to determine the association between food insecurity and demographic predictors. These associations are then applied to tract-level data from the 2009 to 2013 American Community Survey and projected data for 2020 to create small area estimates of food insecurity. We find broad consensus between our two methods. For both time periods, food insecurity is highest in southern sections of the city of Atlanta and its neighboring suburbs. Projections to 2020, however, show that food insecurity rates are projected to increase in outer-ring suburbs east and west of the city while decreasing in the urban core. These results highlight the need to further adapt antihunger efforts for often sprawling suburban communities, where poverty rates are increasing but spatial mismatch combined with poor transit access might hinder access to food assistance.     

基于多维分析框架的中国城市收缩时空演化特征分析

从城市收缩的维度类别、维度数量、时序演化3个方面入手,提出了一套新的多维度分析框架,并将其应用于中国城市收缩的时空演变特征分析。结果表明：1）在1995—2000、2000—2005、2005—2010和2010—2015这4个时期中,人口收缩城市占中国城市总量的比例分别为9.55％、20.34％、15.34％和19.72％;经济收缩城市占比分别为5.32％、4.85％、0.47％和8.29％;空间收缩城市占比分别为7.04%、3.44%、3.76%和1.72%。2）相对于欧美发达国家,中国的城市收缩现象并不是很严重,大部分人口收缩城市的收缩率均低于3％。3）中国的城市收缩现象存在3个悖论：93.03％的人口收缩城市的建成区面积在扩张,92.37％的人口收缩城市的国内生产总值（GDP）在增长,94.57％的经济收缩城市的建成区面积在扩张。这与中国的要素依赖型经济增长模式和地方政府的土地融资模式等存在较强的关系。文章所构建框架具有较好的灵活性和较强的适应性,有助于增强收缩城市研究的可比性。此外,该框架在推动城市多维度收缩的类型学研究,分析城市收缩的时序演化规律等方面也具有较大的潜力。     

U.S. Intercounty Migration in the 1990s: People and Income Move Down the Urban Hierarchy

Internal migration within the United States continues to transform both the magnitude and composition of population at all geographic scales. During 1994 ‐ 1995, the majority of counties gained both people and income, largely as a consequence of net outmigration by higher income migrants from the nation's most populous cities. Regionally, net gainers of both people and income included counties in the West and South as well as other areas renowned for environmental amenities. Spatially, net migration flowed down the urban hierarchy from large central cities to adjacent suburbs which, in turn, exported migrants to exurban areas. Large cities tended to exchange migrants with nearby counties as well as other large cities. Migration patterns such as these are contributing to spatial deconcentration and economic disparity.     

上海市中心城社会区分析

以第五次人口普查数据为基础,对上海市中心城社会区进行研究。结果表明,老年与外来人口、社会经济地位、居住条件、商服与农业人口和公房住宅是形成转型期上海中心城社会区的5个主要因子。城区社会区可划分成6种类型:老年人口集中的旧城区、高社会经济地位居住区、单位公房居住带、人口导入的新建住宅区、外来人口聚居区、农业人口散居区;城市社会空间在整体的同心圆结构基础上呈现出与扇形、多核心结构的综合。并从城市发展的历史、城市规划、土地使用制度改革与旧城改造、户籍管理制度、住房福利分配制度及市场化改革等方面探讨了其形成机制。     

The suburbanization of poverty? An alternative perspective

A popular and powerful narrative focuses on a crisis of suburban decline in the United States. However, a consensus regarding the scope and scale of one dimension of suburban decline—poverty—is hindered by the use of contradictory definitions of suburban space. This research presents an alternative approach to measuring suburban poverty that is less computationally intensive yet capable of capturing complex shifts in the spatial distribution of poverty within metropolitan areas. An analysis of the distribution of poverty in the largest 100 metropolitan areas between 1990 and 2007–11 concludes that while poverty is increasing in the low-density suburbs of a handful of large metropolitan areas, the more general trend in most other metropolitan areas is an increase in poverty in moderately dense residential areas. Implicated in these trends are long-term trends in metropolitan area economic growth, a secular decline in inner-ring suburbs, and the impact of gentrification on housing opportunities for at-risk populations in large cities.     

The Spatial–Temporal Hierarchy of Inequality in Urban China: A Prefectural City–Level Study

Inequality has been the subject of intense debates in China, but inequality across cities remains less studied. This article investigates economic inequality based on prefectural-level cities during the period from 1990 to 2010. Statistical analyses indicate that interregional inequality among cities has increased, which is mostly attributable to widening intraregional inequality, especially within the western region. The high gross domestic product (GDP) per capita clusters emerged in the Pearl River Delta in the 1990s, spread to the Yangtze River Delta in the 2000s, and then reached north China in the 2010s. In contrast, the number of low GDP per capita clusters significantly increased in the central and western regions in the 2010s. In addition, the significance of national development zones and foreign direct investment indicates the greatest effect of globalization on the increasing intercity inequality. Decentralization also contributes to the intercity inequality of China. We suggest that in addition to national programs aimed at reducing the inequality between the eastern region and the rest of China, efforts are needed to reduce inequality within each region through provincial and local government policies, especially in western China. Key Words: China, cluster, decentralization, globalization, regional inequality, urban inequality.     

Defining the Historical Northeastern Forested Boundary of the Great Plains Grasslands in the United States

The Great Plains is the grasslands of the central United States, but precise delineation of this region has evaded agreement due to the transition between Great Plains grasslands and forests of the eastern United States. After comparing Great Plains delineations in readily available geographic information system layers, I established a northeastern boundary using evidence from historical tree surveys during the 1800s. Additionally, I described tree presence within the Great Plains over time and potential drivers of change. The definition documented here diverges from others by including most of Iowa and part of Illinois, and even small sections in Indiana and Wisconsin, but excluding Missouri due to regular tree presence overall at landscape scales of ecological subsections. In this definition, the Great Plains had an extent of 2.29 million km² in fifteen states, including Indiana and Wisconsin, and 2.19 million km² after removal of open forests in Oklahoma and Texas. Tree presence occurs within the Great Plains and tree encroachment is not a new process; however, tree encroachment is increasing in the Great Plains, which causes a decrease in the grasslands region. Nevertheless, clarifying the historical eastern boundary provides a solution to the problem of competing versions of the Great Plains region. Key Words: ecotone, prairie, savanna, tree encroachment.     

Solar Rich and Water Poor: The Case for Solar Desalination in El Paso,Texas

Desalination is an increasingly important water source for the sunny, arid city of El Paso, Texas. As the city’s population grows, El Paso Water, the city’s water utility, has had to drill deeper into the Hueco Bolson aquifer, a primary water source for El Paso. This deeper drilling into the Hueco Bolson, however, has yielded progressively more saline water. In response, El Paso Water and administrators from Fort Bliss jointly constructed a reverse osmosis desalination plant to protect the Hueco Bolson’s freshwater supplies and expand the city’s water sources. Reverse osmosis water desalination, however, is an expensive, energy-intensive process currently dependent on carbon-heavy fossil fuels. Solar energy, however, is an abundant, carbon-free energy source that could potentially reduce the energy costs and carbon footprint of the reverse osmosis desalination process. We hypothesize that building a solar microgrid that supplies El Paso’s desalination plant with energy in tandem with the regional grid will reduce the plant’s energy expenditures in the long term compared to solely buying energy from the regional grid. We used the Hybrid Optimization for Multiple Energy Resources (HOMER) model created by the National Renewable Energy Laboratory. The results suggest that a solar microgrid whose modules use one axis tracker could reduce the plant’s energy expenses. Key Words: desalination, solar energy, water resources.     

中国东北三省城市收缩的识别及其类型划分

城市收缩是一个受经济全球化影响,并具有区域地方特征的世界性经济社会现象,如何构建快速城镇化进程中“中国化”城市收缩研究理论分析框架,为世界城市收缩研究提供中国经验,是新时期中国地理学者、城市规划工作者亟需重点关注和研究的新命题。本文认为城市收缩本质是城市“发展势能”的相对弱化或绝对退化而引起以人口为核心的经济发展要素的再区位和城市功能形态空间重构的响应过程或状态,其是一个综合概念,一个基于人口变化、经济变化、投资消费变化与财政变化等的多维一体过程,据此构建基于“二步诊断法”的城市收缩识别体系及其类型划分标准,同时针对中国最具典型和代表性的东北三省开展城市收缩的实证分析。结果表明：① 东北三省存在明显的城市收缩现象、且呈现出区域化的发展演化趋势;整体可归纳为资源依赖型收缩城市、“虹吸”型收缩城市、综合型收缩城市及区位制约型收缩城市4种模式,其中资源依赖型收缩城市是主体,占据了整个收缩城市的2/3;② 空间上整体呈现出北高南低的空间格局,与经济发展重心不断南移相呼应;③ 指标维度收缩整体遵循“投资消费与经济下行→人口收缩→财政收缩”的内在演化逻辑关联;④ 立足于“二步诊断法”的城市收缩识别体系及其类型划分标准反映出当前基于人口变化学的识别标准的合理性及其局限性——人口变化学能够在很大程度上识别收缩城市,但是对于划分收缩城市类型、揭示收缩城市内在耦合机理具有一定的局限性;⑤ 实证结果表明“二步诊断法”是合理可行的,其可为中国城市收缩的识别、东北振兴政策的制定提供工具支撑与参考依据。     

A resurgence in urban living? Trends in residential location patterns of young and older adults since 2000

ABSTRACT

Some have heralded a resurgence of urban living in the U.S., particularly among young adults. Are Americans abandoning suburbs in favor of more urban lifestyles? What is the scope and scale of this urban resurgence? We develop a typology of neighborhoods to analyze the residential location of young and older U.S. adults from 2000 to 2011–15. Census and national travel survey data reveal that suburban population growth continues to outpace that in urban neighborhoods. Although young adults are more likely than older adults to live in urban neighborhoods, recent urban population growth is neither associated with suburban decline, nor being led by young adults. Significant recent population growth in the newest, suburban neighborhoods suggests that greenfield development remains the primary means to increase American housing supply. Shifting metropolitan growth from the suburban fringe would likely require expanding housing supply in urban neighborhoods, and bringing urban amenities to established inner-ring suburbs.     

Modeling River Connectivity Using the Barrier Assessment Tool and Available Data on Registered Dams in the Guadalupe–San Antonio River System,Texas

The rate of dam building has declined in the United States, but dam building is still considered an integral part of water supply management, particularly in arid and semiarid regions. Understanding how dams affect river connectivity is a key component of river basin management. This study analyzed the spatial and temporal patterns of fragmentation in the Guadalupe–San Antonio River System (GSARS) and how these patterns were related to dam size, age, and purpose. Using a shapefile of registered dams and the National Hydrography Dataset High Resolution (NHD-HR) as input data for the Barrier Assessment Tool (BAT), six successive connectivity models were created. The average length of functional river networks (FRNs) decreased over time but the number of FRNs over 100?km stayed relatively stable. Fragmentation in the GSARS was concentrated around urban centers, and the majority of fragmentation occurred gradually as dams separated small FRNs along tributaries and headwaters. This gradual decline in longitudinal connectivity was punctuated by sporadically large separations of river networks by particular dams based on their location and time of commissioning. The methodology presented here provides a way to analyze both the extent and the temporal evolution of fragmentation in a river system. Key Words: Barrier Assessment Tool (BAT), fragmentation, functional river networks, river connectivity.     

Urban transformations,migration and residential mobility patterns in African secondary cities

Abstract

Urban growth is a significant trend in Africa. Scholarly attention and urban planning efforts have focused disproportionately on the challenges of big cities, while small and medium-sized urban settlements are growing most rapidly and house the majority of urban residents. Small towns have received some attention, but very few studies have focused on secondary cities. This paper offers a study of urban transformations, migration and residential mobility patterns in Arusha, a rapidly growing secondary city of Tanzania. Arusha functions as a major attraction for migrants and in-migration is a central dynamic shaping transformation processes in central areas characterized by high population turnovers, vibrant rental markets and widespread landlordism. There is also a considerable degree of intra-urban residential mobility within and between central areas. Intra-urban residential mobility is the most important dynamic shaping transformation processes in peripheral areas characterized by long-term urban residents moving from central parts of the city as part of a process of establishing themselves as homeowners. Overall, the paper provides crucial insights on how migration and residential mobility patterns influence processes of urban growth and transformation in the context of large secondary city, and thereby contributes to fill a significant knowledge gap on secondary cities in Africa.     

基于百度慧眼的中国收缩城市分类研究

收缩城市是快速城市化过程中不可忽视的一类城市,按照城市人口变化格局,开展收缩城市分类研究,是发现城市人口“空洞”及变化特征的重要一环。国际上将收缩城市主要分为穿孔型、圈饼型和边缘型,中国的收缩城市究竟包括哪些类型?尚缺少研究证实。本文以中国实体城市为分析单位,利用百度慧眼2016年11月─2018年11月200 m格网的常住人口数据,发现常住人口减少的实体城市共1506座,占实体城市总量（3022座）的49.8%。选取人口较为密集且在研究时段内出现严重收缩现象的126座收缩城市为研究样本,探讨中国收缩城市分类问题。分析表明：126座收缩城市样本多分布在秦岭淮河一线以北地区,包括穿孔型、全局型、局部型、圈饼型、边缘型等5种类型。其中,穿孔型收缩城市最多,共47座（37.3%）,为中国收缩城市的主导类型,主要分布于黑龙江、内蒙古、甘肃;全局型收缩城市有33座（26.2%）,主要分布于甘肃、陕西;局部型收缩城市有25座（19.8%）,主要分布在黑龙江、内蒙古;圈饼型收缩城市有18座（14.3%）,主要分布在内蒙古;边缘型收缩城市有3座。“重速度、轻质量”的前半程城镇化,以“增长”为主导的城市规划执念,资源枯竭或经济转型导致传统工业企业衰落解体,政府主动调整下的产业转移等是产生穿孔型收缩城市的主因。研究为政府精细调整城市发展重心、优化土地利用结构、提高城市宜居性、开展收缩语境下的城市规划与设计,提供了科学依据。     

东北三省城镇收缩的特征及机制与响应

基于城镇收缩视角认识东北三省人口流失与经济衰退问题,对深化中国老工业基地转型理论具有重要意义.本文以东北三省县级市(县)为研究对象,利用ArcGIS与空间计量方法,分析增长与收缩城镇的特征与空间关系,研究收缩城镇的职能差异和空间分布格局,探讨区域城镇收缩的形成机制与应对措施.结果 显示:2000年以来,东北三省出现了明...     

城市收缩时代的适应战略和空间重构 ——基于日本网络型紧凑城市规划

通过对日本网络型紧凑城市规划的发展机制、发展政策和代表性案例--富山市和宇都宫市的探讨,归纳总结了日本中央和地方城市政府的收缩城市规划战略政策和空间重构规划方案,借此为陷入收缩境况的中国城市在战略取向和空间重构方面提出有益启示：1）勇于接纳和面对人口减少和城市收缩这一客观事实,积极采取激活城市收缩所带来的机遇的适应性战略,而不是采取促使人口再度增加的应对性战略;2）充分考虑人口减少和老龄化社会并存的城市收缩时代特征,通过城市功能集聚的“据点化”战略和公共交通系统主导的“网络化”战略,构建多中心连接的网络型紧凑城市空间结构;3）根据人口数量变化预测结果,动态地推动城市规模的精明收缩,开展匹配存量规划或减量规划的规模适当化规划。     

法国巴黎区的规划与整治及其对上海建设的启示

本文对法国巴黎区城市膨胀扩展过程、城市规划指导思想由同心圆模式向轴线发展模式、由单个要素转移到郊区城市综合功能开发转变的原因进行了分析，并对以巴黎城市副中心和郊区新城建设等为主要内容的城市规划经验教训进行了介绍和总结。在此基础上，结合上海市经济社会发展的条件和目标，分析了上海市规划中存在的郊区城市规模小、城市工业“空洞化”、城市建设政策措施协调配套以及浦东建设项目利用效益低下等几个城市建设面临的主要问题，并提出了相应的改进建议。     

The role of Leipzig’s narrative of shrinking

An important claim for the categorisation and study of shrinking cities is that the experience of governance across these cities may offer an alternative to hegemonic discourses of growth. However, there are methodological problems associated with categorizing then researching shrinking cities. Two key problems are: first, the category hides a multiplicity of cause and effect and; second, the danger of fetishizing the city against the reality of broader urban drivers of change. It is argued that the use of governance narratives is a means to addresses this, as narratives focus us on cities as places of practice. We apply the approach to Leipzig, once shrinking but now one of Germany’s fastest growing cities. We conclude that while there was a significant attempt to articulate an alternative to growth, it remained dominant suggesting the need to develop a taxonomy of shrinking cities where not all offer an alternative vision of “development”.     

吉林省城市增长与收缩的分异特征、成因与对策

利用人口与经济变化组合关系和二分类Logistic回归模型,探索新时期吉林省城市发展的空间分异现象及成因。结果表明:(1)吉林省形成了绝对增长型、绝对收缩型、精明增长型和人口集聚中心4种城市发展类型。(2)绝对增长型城市产业结构不断多样化,科技发展对经济增长的贡献率日益提高;精明增长型城市先进制造业、生产性服务业迅速发展,但生活性服务业发展相对不足;绝对收缩型城市以传统制造业为主导产业,城市竞争力不断丧失,存在持续收缩的发展趋势;人口集聚中心凭借发达的公共服务业抑制了主导产业衰退背景下的人口流失现象。(3)产业结构、企业组织、政府调控以及集聚-扩散效应是新时期吉林省城市增长与收缩分化的成因。顺应区域城市发展趋势,编制存量和减量规划,分类引导城市的精明增长与收缩,是未来吉林省空间重构的主要发展路径。