Measurement of Urban Fringe Sprawl in Nanjing between 1984 and 2010 Using Multidimensional Indicators

Due to the global increases in urbanisation rates, urban sprawl has become a worldwide issue. In China, the development of rural areas has been affected by urban expansion and adjustments of metropolitan areas by administrative divisions that have led to losses in agricultural lands and ecosystem services. There is the ‘paradoxical’ desire for governments to promote rural development and protect land resources. Urban fringe sprawl is a prominent issue in the process of rural development. Identifying and measuring sprawl at the urban fringe could assist policymakers to either encourage or discourage this phenomenon. This paper demonstrates use of multidimensional indicators to effectively measure urban fringe sprawl by remote sensing, in addition to demographic and socio‐economic data. Using integrated indicators observed in the recent Chinese development context, urban fringe sprawl was measured comprehensively for Jiangning, a district in the city of Nanjing, China. This study indicates that Jiangning is sprawling rapidly. The results also show that the multidimensional indicator approach could provide decision support to create effective long‐term land‐use planning policies for controlling urban sprawl patterns.     

The Influence of Local Urban Containment Policies and Statewide Growth Management on the Size of United States Urban Areas*

Abstract. In an attempt to slow the consumption of urban land for a given population, and the negative outcomes thought by some to be generated by such sprawl, regulations in the form of (i) the local imposition of urban containment policies that restrict or prohibit the amount and/or the type of urban settlement beyond a certain line and (ii) the statewide enactment of mandatory growth management requirements for all local governments have been enacted in the United States. This paper describes a regression‐based analysis that finds that different forms of these policies are achieving their desired goal of shrinking the square mile size of an urban area. A comparison of the influence of the various forms of urban containment and growth management policies with other “natural evolution,”“flight from blight,” and “fiscalization of land use” factors that also influence the square mile size of an urban area is made, and policy implications are offered.     

基于GIS的西安市城市扩展与模拟研究

本文以西安市为研究区域,以2002年ETM影像和2007年TM影像遥感数据为城市扩展动态变化的主要信息来源,采用逻辑回归模型并结合GIS技术对西安市的城市空间扩展进行模拟。研究选取了道路、河流、地裂缝、地面沉降、人口和GDP等6个因子,建立了西安市城市扩展的逻辑回归模型,并根据所建立的模型对西安市的城市扩展进行了模拟,结果表明,所建立的逻辑回归模型能够较好地模拟西安市的城市扩展,对西安市城市扩展的驱动力具有较强的解释作用,其中对城市扩展影响最重要的因素为距道路距离。     

ON THE VALUE OF FOREGONE OPEN SPACE IN SPRAWLING CITIES

Foregone benefits of the open space that is sacrificed through urban sprawl are hard to quantify. We obtain a simple benchmark measure by introducing a demand for trips beyond the urban boundary into the monocentric city model. The externality arises from the increase in travel costs that expansion of the city imposes on its prior inhabitants. An empirical application illustrates the moderate informational requirements. It indicates that open space externalities warrant rather mild restrictions on urban expansion.     

Exploring the land development process and its impact on urban form in Hamilton, Ontario

The form of many Canadian cities has dramatically evolved over the past six decades due to urban sprawl. Several patterns can characterize this evolution including unlimited horizontal expansion of the city, leapfrog, and low‐density residential development at the outskirts, and widespread strip commercial and power centre retail development. Hamilton, Ontario is an example of a Canadian city that has experienced suburbanization and sprawled development for several decades. However, the nature of this sprawled development is unclear and its impact on urban form is not entirely understood. In this article, several hypotheses pertaining to sprawled land development and urban form are postulated and tested. The tests rely on point source data of the developed land parcels in Hamilton during the period 1950–2003. A number of spatial statistics techniques, including kernel estimation and complete spatial randomness (CSR) K‐function tests, are employed to examine the emerging nature of urban form. We hypothesize that while the city has been sprawling, the ongoing land development process is leading urban form into multinucleation. To support this assumption, we further hypothesize the existence of an interdependent spatial relationship between residential and commercial land uses at the emerging nuclei. Accordingly, we examine the strength of co‐clustering among these land use activities over time. The findings indicate that while the city has been sprawling, several consequent urban nuclei with mixed land use activities have been emerging and become more visible in recent years. This is an indication that the city's form is progressively becoming multinuclear. Furthermore, the estimates for the 1990s indicate interdependence between the locational patterns of residential and commercial land development. Co‐clustering between these two types of land uses is bi‐directional and occurs at a time lag of three to seven years. These findings affirm the existence of interdependence between land use activities at the observed nuclei, which support the emergence of a multinucleation.     

THE EFFECT OF TRANSPORTATION SUBSIDIES ON URBAN SPRAWL*

ABSTRACT This paper provides theoretical and empirical analyses of the effect of transportation subsidies on urban sprawl in a two‐mode urban spatial model. Comparative static analysis shows, among other things, that the urban area contracts with a public transit subsidy but expands with an auto subsidy. The paper provides the first empirical test of these hypotheses and finds that the spatial size of the urbanized area shrinks with an increase in transit subsidies but increases at a decreasing rate with auto subsidies.     

Decline and sprawl: an evolving type of urban development – observed in Liverpool and Leipzig1

Much of the empirical research on urban sprawl has been carried out in North America and most theoretical studies on this problem have been concerned with expanding urban areas. This study differs, firstly in that it is concerned with sprawl in two European cities, Liverpool in England and Leipzig in Germany, and secondly because both these cities are in decline. This presents an opportunity to explore whether the process of urban sprawl is somehow specific in a situation of urban decline and what its outcomes might be for both urban form and urban policy.     

URBAN GROWTH EXTERNALITIES AND NEIGHBORHOOD INCENTIVES: ANOTHER CAUSE OF URBAN SPRAWL?*

ABSTRACT This paper suggests a cause of low density urban development or urban sprawl that has not been given much attention in the literature. There have been a number of arguments put forward for market failures that may account for urban sprawl, including incomplete pricing of infrastructure, environmental externalities, and unpriced congestion. The problem analyzed here is that urban growth creates benefits for an entire urban area, but the costs of growth are borne by individual neighborhoods. An externality problem arises because existing residents perceive the costs associated with the new residents locating in their neighborhoods, but not the full benefits of new entrants which accrue to the city as a whole. The result is that existing residents have an incentive to block new residents to their neighborhoods, resulting in cities that are less dense than is optimal, or too spread out. The paper models several different types of urban growth, and examines the optimal and local choice outcomes under each type. In the first model, population growth is endogenous and the physical limits of the city are fixed. The second model examines the case in which population growth in the region is given, but the city boundary is allowed to vary. We show that in both cases the city will tend to be larger and less dense than is optimal. In each, we examine the sensitivity of the model to the number of neighborhoods and to the size of infrastructure and transportation costs. Finally, we examine optimal subsidies and see how they compare to current policies such as impact fees on new development.     

Shifting meanings in changing contexts: the role of the creative city in Shanghai,Hong Kong and Taipei

Abstract

This paper probes the underlying motives behind the adoption of the ‘creative city’ policies in Shanghai, Hong Kong and Taipei. It argues that while the global appeal of the creative city is commonly attributed to urban entrepreneurialism, this reason alone is insufficient in explaining the so-called ‘cultural turn’ in these three cities, because none of them ascribe to the conventional format of the post-industrial ‘entrepreneurial’ city. In order to identify other major forces driving the adoption of creative city initiatives in Shanghai, Hong Kong and Taipei, this work delves into the ways in which the idea of the creative city is reworked within the context of global city making. The study found that in addition to urban entrepreneurialism, the inherited cultural policy agenda, which largely stems from national interests, also plays a significant role in directing (and changing) the ‘global cultural city’ making process. By looking into different roles attached to the ‘imported’ policy discourse of the creative city in Shanghai, Hong Kong and Taipei, this study not only contributes to the understanding of urban cultural policies within the Chinese-speaking world and East Asia more generally, but also lends some insights to the developing field of cultural policy mobility.     

EMERGENCE OF LEAPFROGGING FROM RESIDENTIAL CHOICE WITH ENDOGENOUS GREEN SPACE: ANALYTICAL RESULTS

Leapfrog development is a typical form of sprawl. This paper aims at analyzing the existence, size, and persistence of leapfrogging in a dynamic urban economic model with endogenous green amenities. We analyze whether incoming households choose to settle at the fringe of the city or to jump further away depending on their preferences and the structure of the city. We first provide an analytical treatment of the conditions and characteristics under which a first leapfrog occurs and show how the optimal choice is affected by the size of the city, income, commuting costs, as well as the size of the area where green amenities are considered. We then study how further leapfrogging and multiple urban rings may appear and be maintained in the long‐run equilibrium, and how infill processes take place through time.     

中国城市蔓延时空动态识别及驱动因素探测

城市蔓延已成为全球性的热点问题。基于2000-2017年夜间灯光数据和LandScan人口分布数据,以中国343个地级及以上城市为研究单元,利用能够细分城市内部密度差异的蔓延度指标测度城市蔓延状况,并运用趋势分析、探索性时空数据分析技术（ESTDA）和地理探测器等方法,分析中国城市蔓延变化趋势及时空格局,探究影响城市蔓延的驱动因素。结果表明：①2000-2017年,中国城市蔓延整体表现为中高度蔓延,在空间分布上,蔓延度呈现西北高、东南低的空间格局。②18年间,47%的城市其蔓延度基本保持不变,位于省际交界处的城市其蔓延度呈现增大的趋势,而少数省会城市或区域中心城市的蔓延度则呈现减小的趋势。③蔓延度的局部空间稳定性自东南地区向西北、东北地区递减。蔓延度存在较强的空间依赖性,且城市数量由低LISA弯曲度到高弯曲度大致呈现金字塔结构,79%的城市其蔓延度的波动性较弱;蔓延度没有出现明显的时空跃迁,空间凝聚性较强,空间格局较为稳定,存在一定的转移惰性。④第三产业产值、GRP和房地产开发投资额是影响中国城市蔓延的最主要因素。     

A CONSOLIDATED MODEL OF MONOCENTRIC CITIES AND AN EMPIRICAL ANALYSIS OF URBAN SCALES AND LAND PRICES IN CHINESE CITIES*

ABSTRACT Motivated by the newly established Chinese urban land markets, we develop a theoretical model that unifies the “closed” and “open” features of the classical monocentric city model. The model features interactions between permanent urban residents and migrants and exhibits a distinctive equilibrium pattern. The theoretical model is tested empirically, using recent Chinese city‐level data. The empirical findings indicate that market forces now play an important role in urban expansion and land price formation, while various forms of government planning are still influential. Our results show that migrants exert a less pronounced impact than the classical “open” city model has suggested.     

Barrio Women's Invited and Invented Spaces Against Urban Elitisation in Chacao,Venezuela

Outright victories against urban elitisation are rare in the current urban revolution. This article highlights how urban elitisation is confronted in Chacao, the most elite and urban part of Venezuela. Initially it reviews how this urban elitisation created the main economic, political and military strongholds of the opposition to the Bolivarian revolution. Then, in contesting it, the urban and Bolivarian revolutions feed each other through women's participation in invited and invented spaces of citizenship. From such spaces, Chacao women in their settler's movement organised struggles of insurgent citizenship to stop elitist urban renewal agendas and develop further forms of insurgent urbanism to conduct an urban renewal from below and establish a New Socialist Community for 600 families. They emerged as a revolutionary class to implement Bolivarian policies addressing the inefficiency and opportunism of the bureaucratic state and contesting urban elitisation with an anti‐capitalist and anti‐imperialist insurgent urbanism.     

The general equilibrium effects of high-occupancy vehicle lanes on congestion,sprawl, energy use,and carbon emissions

High-occupancy vehicle (HOV) lanes have been promoted to encourage carpools, reduce traffic congestion, and improve air quality. At the partial equilibrium level, commuting with three workers per automobile clearly reduces highway congestion, lowers carbon emissions, and saves energy compared with three single drivers. This paper develops a numerical urban simulation model to generate the general equilibrium effects of HOV lanes on urban spatial structure, energy use, and greenhouse gas emissions. The major findings are that while HOV lanes reduce traffic congestion and improve welfare, the fall in transportation cost leads to urban sprawl, which results in higher dwelling energy use and a larger carbon footprint. Overall, the HOV lane policy has little effect on total energy consumption and carbon emissions. This is another classic case of general equilibrium effects reversing the partial equilibrium effects of an urban policy. In contrast, a gasoline tax policy leads to less urban sprawl but is less effective at lowering energy consumption and carbon emissions. Imposing congestion tolls is a more effective tool at reducing traffic congestion, saving energy, and lowering carbon emissions.     

Airport delays and metropolitan employment

This study provides the first empirical assessment of the impact airline delays have on urban employment. While previous works have suggested that road congestion can slow down regional development, the influence of air traffic delays on metro‐level jobs has not been examined comprehensively. The present study uses a nine‐year panel of quarterly data, which covers passenger airline traffic and delays at airports across urban areas in the United States. The panel also includes data on total and industry‐specific employment at the metropolitan‐area level. Our empirical estimates of the impact of air traffic on total employment are comparable to previously reported measures in the literature. However, we find that service‐sector employment is less sensitive to air traffic than other studies suggested. We provide new evidence confirming that delays have a negative effect on employment, a finding that is robust to various specifications of our empirical model. Our results indicate that a 10 percent increase in the number of delayed flights leads to up to a 0.15 percent decrease in total and service‐sector employment, a 0.47 percent decline in leisure and hospitality employment, and a 0.7 percent reduction in the employment level of goods‐producing jobs.     

Learning to Think as a Region: Connecting Suburban Sprawl and City Poverty

Throughout the US there is an increasing debate about the nature of urban development, including such aspects as suburban sprawl and continuing central city poverty. This debate is driven by a range of motivations, including concerns about the effect of growth on the environment, quality of life, government efficiency, economic competitiveness, and equity. Several metropolitan areas have developed new governmental and fiscal structures or land use policies to address problems caused by growth, or by inequalities within regions. A detailed case study of Chicago shows how different groups deal with these issues politically. The article concludes with an overview of the policies most likely to be successful.     

城市空间扩散增长模型与模拟

城市模型模拟是上世纪90年代上半期形成并迅速发展的地学计算理论、方法与应用研究的最重要领域,国外以M. Batty为代表的规划与地理学家们进行了开创性的研究,取得了很多有用成果。本文借鉴这些学者的研究思路,从城市土地利用与开发的视角,利用疾病感染、传播机理的模拟方法,研究城市空间扩展、演化动力学过程的模型模拟问题;为模拟城市土地开发利用在不同阶段的表现与特征,研究了基本模型的不同变换形式;讨论了基于细胞自动机模型的城市空间扩展模型的计算结构,依据模拟结果,探讨了以城市形态扩展特征为指标进行城市分类的可行性,尝试对城市地理学的模型模拟方法作一拓展。     

The ‘creative township’ in the post-apartheid: globalisation,nation building or gentrification?

ABSTRACT

This paper analyses the ambiguities of post-Apartheid public cultural policies in South Africa by focusing on the case of the Red Location Museum and Cultural precinct (RLMCP), a multisectoral project for socio-economic development, based on tourism, art, culture, heritagisation and urban regeneration, implemented in Red Location, one of the oldest townships of Port Elizabeth. In the post-Apartheid period, cultural policies have been employed as catch-all policies that could lead to urban renewal, desegregation and development. The case of the RLMCP drives home how efforts to use art and culture as leverages to transform townships into the core of the creative city and into the prototype of a new form of neighbourhood led to exclusionary representations and patterns; moreover, it is an example of how cultural policies enforce gentrification dynamics at the local level, in the name of restructuring urban governance and rescaling the city to the global dimension.     

HOW DO DIFFERENCES IN PROPERTY TAXES WITHIN CITIES AFFECT URBAN SPRAWL?*

ABSTRACT We develop a duocentric‐city model and show that the ratio between the property tax in the suburbs and in the center has an ambiguous impact on the size of the city. We test this model by using a dataset of effective property tax rates which we developed using GIS techniques for central cities and suburbs in 445 urbanized areas. Results from the empirical analyses suggest that a lower property tax rate in the suburbs as compared to the central city is associated with more expansive urban growth and a greater level of decentralization of population and employment.     

城市蔓延的多维度思考

半个多世纪以来,城市蔓延引起了广泛关注,取得了显著的研究进展,但也存在一些不足。本文就城市蔓延的内涵界定、测度方法、动力机制及中国大城市空间扩张的特殊性进行讨论与辨析,认为：城市蔓延是指那种盲目而无计划的、分散而非连续性的、用地功能单一且低密度的、过度依赖机动化出行且导致人地关系日趋紧张的不可持续的城市空间扩展模式;具有复杂性、阶段性、区域性、相对性等特点;是经济因素、制度因素、政策因素、技术因素、规划因素、社会因素、文化心理因素或行为因素等综合作用的结果;城市蔓延是过度郊区化的表征,是与特定的时空条件相联系的,需要从中心城区与郊区互动演进的视角来考察;中国大城市的交通拥堵和空气污染问题正在从城市中心向郊区扩展,新一轮城市规划必须对此给予足够的重视。