Congestion Tolling and Urban Spatial Structure

According to the standard model of urban traffic congestion and urbanspatial structure, congestion tolling results in a more concentrated city. In recent years, a new model of rush-hour urban auto congestion has been developed that incorporates trip-timing decisions—the bottleneck model. In the simplest bottleneck model optimal congestion tolling without toll-revenue redistribution has no effect on trip price because the efficiency gainsexactly equal the toll revenue collected. Optimal congestion tolling then has no effect on urban spatial structure. This paper formalizes and extends this result.     

夔州城市形态与空间结构的演变

地处长江三峡中心区域的夔州,其治所由白帝—赤岬城转移到"瀼西",由利于军事防守的险峻之地迁至适于民居及进行商贾贸易之处,它们分别代表军政要塞式与经济、行政功能兼具式两种不同的治所城市模式,其转移适应了峡区政治、军事功能下降和经济功能增强的需要。与此同时,自宋至清末,建于"瀼西"的夔州城成为长距离贸易中转站及地区市场中心,城市形态的形成与变化亦受此影响,特别是为明清时期夔州府城的发展提供了更大的运作空间。城市功能区的"垂直分布"与城外街区的扩展,既与峡区的地理环境相适应,又符合商业发展和人口增殖的需要,是峡区城镇布局的典型形式。     

Information Technology Impacts on Urban Spatial Structure in the Chicago Region

This paper examines the impact of information technology on urban spatial structure in the Chicago region. Urban scientists are challenged to understand in what ways information technology has influenced the distribution of urban economic activities: concentration or dispersion. Using data collected in the Chicago region, orientation of establishments toward the center is tested to separate the impact of locational features of centers from the impact of information technology. The result reveals that information technology has attraction as well as spillover effect on urban spatial structure and thus concentration rather than dispersion is dominant at a local scale in the Chicago region. It was found, however, that center‐orientedness varies depending on the sector.     

The Structure and Context of the Urban Growth Coalition

This article examines the perception of local chambers of commerce regarding the urban growth coalition, and compares their observations with those of contemporary urban theorists. The chambers perceive the developmental community as dominated by business groups associated with land-use intensification and by elected officials. The chambers see manufacturing, retail, and service-sector firms as part of a less prominent constellation of developmental actors, and perceive virtually no developmental role for neighborhood or environmental groups.     

20世纪后半期美国大都市区空间结构趋同现象及其理论意义

美国的大都市区化,反映了20世纪世界城市发展过程中不同于传统城市化的新的规律性现象。在这一过程中,大都市区空间结构出现趋同现象,其主要特点是分散化、多中心格局和大规模郊区化。这种现象对传统城市化理论提出挑战,并要求城市化概念的相应调整。在我国部分城市即将进入郊区化快速发展的关键时期,认识到这一点并在相关规划方面做出调整是很有必要的。     

从集聚经济看城市空间结构

从集聚经济学出发,本文用经济活动转变、经济多样化与交易成本的有关概念、理论解释城市空间结构的演变过程。并指出目前多数研究忽视劳力和消费者空间转移从供求双方对城市空间结构的塑造。     

周原空间结构刍议

2004年初始考古学者在周公庙陆续发现了重要的周文化遗址,这些发现为我们从历史地理角度认识周原的空间结构与内涵提供了新的重要线索。周原自古有广义狭义之分,狭义的周原,是太王从豳迁至岐山,在原上所建的都邑及其附近地区。广义的周原应是在太王创业的基础上经古公、季历、文王几代人的建设、发展壮大而成的周人势力范围。广义周原存在两个权力中心区,依据周人政治中心东进趋势、周公庙遗址新材料等分析推理,得出以今岐山北郭乡、周公庙一带为中心的西区应是周人在广义周原范围内最核心区域的结论。     

明清北京城市社会空间结构概说

对明清时期北京城市的社会空间结构进行探讨,是从城市地理学与城市社会学的视角所作的历史研究.从其内部分区的人口密度可以看出,明清时期北京城市在空间上具有一些新的特点,且在不断变化,而这些特点和变化又分别体现在该时期北京的商业空间、居住空间和社会生活与人际交往空间等方面,由此可以使我们更加深刻和全面地了解明清北京城市的发展程度.     

The Geography of Agriculture of Iowa

The following article on lowa's agriculture is of interest because the Soviet Union considers the highly efficient corn-based livestock economy of the state as an example to follow. Khrushchev's campaign to build up a similar Soviet farm economy based on corn, legumes and other high-yielding feed crops is based in part on observations of Soviet agricultural delegations in lowa. The statistical material in the article is based largely on the U.S. Census of Agriculture, 1954, Vol. I, Part 9, Washington, D. C., 1935.     

The Spatial Structure of the Rural-Urban Fringe: a Multivariate Approach

The literature contains many definitions of the rural-urban fringe, but it is difficult to find consensus on how many zones it contains, or how they can be mapped. It is argued in this paper that transitions within the fringe and at its borders are continuous rather than abrupt. In a study area adjoining London, Ontario, cluster analysis is used, and it leads to the identification of three norms. Membership probabilities are then mapped on the basis of each areal unit's resemblance to these norms through discriminant analysis.
Dans la litterature, il y a beaucoup de definitions de la fringe péri-urbaine, mais on discute le numéro de zones dans la fringe et la méthode de sa cartographie. On raisonne ici que les transitions dans la fringe et sur ses bords sont continues plutôt qu'abruptes. Dans cette étude des environs de London, Ontario, on emploie de 'cluster analysis' qui donne l'identification de trois groupes normatifs. On en fait une carte des probabilités d'adhésion sur la base du correspondance de chaque unité aréale à ces groupes normatifs par l'analyse discriminatoire.     

The Spatial Search Problem: Structure and Complexity

The paper discusses structure and complexity of the spatial search problem. From a set of assumptions it derives a rather general version of the spatial search problem and investigates some of its fundamental properties. Most importantly, the paper shows that the decision problem corresponding to the spatial search problem in this general version is NP-complete.     

Substitutability,Spatial Structure,and Spatial Interaction

This paper attempts to distill the relationship among spatial structure, consumer preferences, and spatial interaction. It introduces the notion of substitutability. Destinations are substitutable in both economic-behavioral and physical-locational senses. Inadequate treatment of this can lead to variations in the estimated parameters of conventional spatial interaction models.     

Set-determined Process and the Growth of Spatial Structure

We present an analysis of the effects of different information flow patterns on the growth of spatial structure in a broad class of systems. Examples are drawn from plant and message diffusion processes, the growth of herding in animal populations and, in particular, the evolution of cities in human populations. We model the actions of an “individual” as a response to gradients in a transformation of the “real” space, this transformation being the individual's information map of the space. Interesting deductions occur as a result of allowing the individual's information map to vary from extremely local to extremely global. In the city growth model for example, if migration decisions are based upon extremely local information, then the system is characterized by instability and the lack of any well-defined spatial structure. As the localness of this information map decreases, the system is characterized by the development of well defined spatial structure with a characteristic distance separating the “cities.” In a particular case, we show that the wavelength of the dominant spatial structure is directly related to the size of an individual's information field. These effects are a consequence of interactions between individuals that arise from the nonlocalness of the information fields. We interpret the early growth stages in these models in terms of linear filters.     

近代芜湖城市空间形态演变及其影响因素

晚清至民国初年,随着开埠通商和米市的兴起,芜湖的城区范围也在不断扩展,同时受到地理环境的制约,新拓展的城区主要分布在城西沿江地带,城市空间形态由传统的沿河带状分布演变为以河口中江塔为中心的"L"型新格局,并逐渐向沿江拓展,发展至今,芜湖已是一座名副其实的江城。分析演变过程背后的原因及其关系,发现在近代芜湖城市空间形态演变过程中,"城"、"港"和"市"三者相互依存、相互促进,保持着依存共生的复杂关系,共同推动着近代芜湖的发展,对三者复杂关系的深入探讨,对于近代整个长江沿江开埠城市的研究也有深远意义。     

Optimizing the Spatial Structure of the Agricultural Production Function

Important characteristics of spatial agricultural production functions are derived by introducing a non‐negative curvilinear spatial demand function for production input intensities. Given the usual neoclassical rationale assumptions of spatial demand for capital and labor inputs under competitive environment of farming in developing agricultural economies, the optimal production levels are determined by optimizing spatial demand for production inputs. Decreasing price‐to‐transport costs ratio (that is, decrease in the prices of capital goods or increase in freight rates) and increasing wage‐to‐travel costs ratio (that is, increase in labor wages or decrease in the travel rate) expand the limits of the (spatial) optimal boundary of the demand for agricultural capital goods and labor input respectively. These effects occur on account of the operation of (positive) spatial price gradient and (negative) wage‐gradient in the market region. It may be noted that elasticities of demand for production factors are spatially variant and have significant effects on the alterations in the structure of agricultural production. However, the spatial optimal solution of production has a complicated relationship with them. The price elasticity has negative and wage elasticity has positive spatial gradients in the market region. Farmers located in the periphery of the market region are not much affected by the proportionate changes occurring in the prices of agricultural capital goods but are more sensitive to the proportional changes in labor wages. Because of a decreasing trend in capital input demand and increase in labor input with distance from the market, capital‐product diminishes with a decreasing rate and labor‐product increases with an increasing rate in the spatial structure of agricultural production. As a result, capital‐labor ratio falls toward zero, which raises profit rate per unit of capital investment especially in the outer part of the market region. The equilibria of optimal production with price elasticity as well as of capital intensity with labor employment (that is, capital‐labor ratio as unity) determine spatial limits of the optimal production zone which is shifted outward subject to the provision of cheap transportation, stabilizing market prices and/or increasing wage rate at the market center. It will help in extending outwardly the optimal spatial limits of capital investment and will mobilize capital resources of farmers in the periphery for efficient and competitive capital‐dominated farming.