The Environmental Impact of Gateways and Hubs in International Air Transportation

国际航空运输是全球经济一体化的基础。连接遥远城市的能力取决于一个精心设计的航空公司互联系统。地理学家长期以来一直对描述和模拟链接网络以及由此产生的可获得性水平及其对全球系统的重要性感兴趣。枢纽和门户等概念是日常使用的，指的是已经发展了特殊基础设施以允许处理长途互动的地方。这项研究项目的目的是在空中网络的空间组织和该结构对环境的可能影响之间建立联系。该项目将审查各种这类安排的成本和效益：通常被称为轮辐式系统(在主要枢纽之间输送流量)和点对点系统(提供更方便的直接联系)的模式。从根本上说，枢纽之间的大流量与点对点对之间更直接但必然更细的流量之间的对比，构成了一系列复杂的权衡。这项研究项目的目的是制定替代网络安排的相对优劣的衡量标准。该项目将从运输成本的角度审查有效流动与这种流动对环境造成相当严重影响的可能性之间的紧张关系。该项目将检查各种飞机航程和尺寸配置的燃油效率。这个话题对枢纽的位置有影响，最终可能会对选择适合首选互动模式的航空客机队的最佳方式产生影响。该项目旨在综合两种截然不同的观点，一种是从单个飞机的能源消耗角度，另一种是从整个网络的角度。到目前为止，研究往往是从一个或另一个方面来解决这个问题，这项研究将加深对系统及其要素之间相互依存的理解。为了实现该项目的目标，将开发运营和网络效率观点之间的创新联系，并在模拟网络的模型中进行测试。由于航空运输渗透到日常生活中，这个项目具有几个社会影响。该项目的影响将从教育影响到提高人们对交通运输中普遍存在的范围经济和规模经济的认识。具体地说，这些结果将使人们更全面地了解航空乘客相互作用的环境和经济成本。该项目还将把对燃料使用和排放的审查更集中地纳入航空运输系统的运营和规划模型。这项研究将有助于解释枢纽作为互动中心的方式，以及对从改善航空公司安全到了解疾病流行病学的一系列应用具有影响的传播模型。事实证明，很难从数量上确定这些主题，交通网络分析将提供在空间背景下衡量这些要素的工具。该项目可能会影响评估和测量网络的方式。

International air transportation is fundamental to the integration of global economies. The ability to connect far flung cities depends on an elaborate system of airline interconnections. Geographers have long had an interest in describing and modeling the networks of links and the resultant levels of accessibility and their importance to global systems. Concepts such as hubs and gateways are in everyday use and indicate places that have developed special infrastructure to permit handling of long distance interactions.The purpose of this research project is to develop a linkage between the spatial organization of air networks and the possible implications of that structure for the environment. The project will examine the costs and benefits in variants of such arrangements: patterns that are often referred to as hub and spoke systems (which channel flows between major hubs) and point to point systems (which provide more convenient direct linkages). At base, the contrast between heavy flows between hubs and more direct but necessarily thinner flows between point to point pairs, poses a complex set of trade-offs. The purpose of this research project is to develop measures of the relative merits of alternative network arrangements. The project will examine the tension between efficient flows from a transport cost point of view, and the potential for such flows to impose rather heavy environmental impacts. The project will examine the fuel efficiency of various aircraft range and size configurations. The topic has ramifications for the location of hubs, and ultimately may have implications for the best way to select an air passenger fleet to accommodate the preferred patterns of interactions. The project aims to synthesize two contrasting views, one from the energy consumption of individual aircraft and the other from the overall network viewpoint. Research to date has tended to come at this problem from one side or the other and the research will develop an increased understanding of the interdependence between systems and their elements. To achieve the project's objectives, innovative linkages between operational and network efficiency points of view will be developed and tested in models of a simulated network. Because of the penetration of air transportation into everyday life, this project has several societal implications. The impacts of the project will range from educational ones to heightened awareness of the prevalence of economies of scope and scale in transportation. Specifically the results will provide a more complete understanding of the environmental and economic costs of air passenger interaction. The project will also bring the examination of fuel use and emissions more centrally into models of the operation and planning of air transport systems. The research will contribute to explanations of the ways that a hub serves as a focal point for interactions, and for models of diffusion which have implications for a range of application from improving airline security to understanding disease epidemiology. These topics have proven quite difficult to pin down quantitatively, and a transport network analysis will provide the tools to measure these elements in a spatial context. The project is likely to influence the way networks are assessed and measured.