考虑换乘费用的城市公共交通票价优化

换乘所产生的附加费用,如时间和票价等,导致配流影响因素产生变化,如果沿用传统方式将降低预测精度和可靠性。通过引入换乘次数和方式等因子计算出行等待、乘车、换乘及风险评估预留时间等,定义广义出行费用与计算方法;建立双层规划模型求解最优票价,最后通过算例分析弹性出行需求、换乘费用、票价之间的关系。计算结果表明,换乘费用对出行需求的影响小于票价优化对出行需求的影响,优化票价随换乘费用增加而加速降低,为公共交通票价优化提供研究依据。     

The organisation of urban agriculture in Cape Town,South Africa: A social capital perspective

This article explores urban agriculture in Cape Town and its organisational forms. Based on a literature review of peer-reviewed articles and grey literature, it examines the state of linkages among urban farmers and various supporting organisations of urban agriculture. Moreover, it examines the coordination of activities among key supporting organisations. By analysing the roles of state and non-state actors and linkages, the article discusses implications for the development of urban agriculture. This article suggests that a lack of effective coordination of initiatives among supporting actors presents a significant pitfall in the development of urban agriculture. Furthermore, the failure of farmers to self-organise is identified as equally detrimental. Therefore, it calls for improved synergies between state and non-state actors involved to ensure that the gains of urban agriculture are enhanced.     

Revealing travel patterns and city structure with taxi trip data

Delineating travel patterns and city structure has long been a core research topic in transport geography. Different from the physical structure, the city structure beneath the complex travel-flow system shows the inherent connection patterns within the city. On the basis of taxi-trip data from Shanghai, we built spatially embedded networks to model intra-city spatial interactions and to introduce network science methods into the analysis. The community detection method is applied to reveal sub-regional structures, and several network measures are used to examine the properties of sub-regions. Considering the differences between long- and short-distance trips, we reveal a two-level hierarchical polycentric city structure in Shanghai. Further explorations of sub-network structures demonstrate that urban sub-regions have broader internal spatial interactions, while suburban centers are more influential on local traffic. By incorporating the land use of centers from a travel-pattern perspective, we investigate sub-region formation and the interaction patterns of center–local places. This study provides insights into using emerging data sources to reveal travel patterns and city structures, which could potentially aid in developing and applying urban transportation policies. The sub-regional structures revealed in this study are more easily interpreted for transportation-related issues than for other structures, such as administrative divisions.     

Who could benefit from a bus rapid transit system in cities from developing countries? A case study from Kampala,Uganda

The present rapid urban growth of cities from developing countries causes negative externalities such as lagging infrastructure development. In combination with rapidly rising motorized vehicle use this leads to severe traffic congestion affecting the mobility of the urban residents. Therefore many urban governments are planning to improve their transport and mobility situations with mass rapid transit systems of which a bus rapid transit (BRT) is a rather easy system to implement at reasonable costs. However, due to high urban inequalities the effects of urban traffic and potential improvements of the urban transport system for the diverse group of urban residents can differ significantly. In our case study Kampala (Uganda) four main groups were identified through cluster analysis of socio-economic and residential data gathered through interviews: extreme poor, poor, middle income and rich. Each group experiences a different mobility with the extreme poor being the most vulnerable group. The planned BRT system aims to decrease the average travel time but risks to exclude the lowest income class since not enough attention is paid to the affordability of the system to all residents. Therefore we argue for a policy that works from bottom up and pays attention to the internal diversity of the population.     

Between Neoliberal Governance and the Right to the City: Participatory politics in Berlin and Tel Aviv

Based on a comparison of Berlin and Tel Aviv, this article investigates the ways in which ensembles of participatory instruments mediate between neoliberal urban regimes and political agency shaping differentially the meaning of participation and the types of claims that can be advanced. The article gives an overview of the recent history of both cities through the lens of participatory politics. Two in‐depth case studies further examine the relationship between participatory politics and claim making in each setting: the recent conflict over a social center in the district of Friedrichshain‐Kreuzberg in Berlin and the Levinsky tent city of 2011 in Tel Aviv. In the concluding section, the article suggests that, rather than assuming that participatory tools either co‐opt movements or can be appropriated by them, we need to rethink the relationship between participatory tools, rights and recognition, and ask how participatory structures and political agency constitute each other in interwoven dynamics.     

数字经济、城市创新与区域收敛

当前，数字经济蓬勃发展，数据已成为除劳动、土地和资本等传统生产要素之外的新要素，能否依托数字经济发展赋能城市创新？文章在对数字经济的概念和内涵进行基本界定后，借助微观大数据构造的"互联网+数字经济"指数，实证分析了2015-2018年中国283个地区数字经济发展对城市创新及创新差距的影响。研究结果显示，数字经济发展能够显著促进城市创新水平提升。其中，人力资本集聚效应和创业活力增强效应是数字经济赋能城市创新的两条重要路径。在替换被解释变量、消除样本选择偏差、选择分位数回归，以及创新性地采用各地级市市长过去修习的专业作为历史工具变量检验后，这一结论依然稳健成立。进一步空间杜宾效应分析表明，数字经济发展具有显著的空间溢出效应特征，不仅促进了本地区创新水平提升，而且对相邻地区的创新产出也产生了实质性影响，有利于缩小区域创新差距，实现区域创新收敛。此外，相较于实用新型专利和外观设计专利，数字经济发展对城市发明专利的影响更显著，说明数字经济发展推动的创新是真正意义上的质量创新而非策略创新。文章为评估数字经济发展的影响效果提供了理论依据和经验支撑，也为理性看待数字经济、防止出现数字鸿沟，实现区域创新均衡发展提供了有益启示。     

A cellular automata-based land-use model as an integrated spatial decision support system for urban planning in developing cities: The case of the Bogotá region

Bogotá and the 17 neighboring municipalities make up one of the biggest metropolitan areas in Latin America. However, despite strong functional interactions within the area, there is no official government body at this level in charge of coordinating authorities and providing solutions to the wide variety of issues arising in the regional urban land system. Aiming at providing an insight on future land-use developments linked to new transport infrastructures and at offering a tool to support territorial decision-making, this paper presents a cellular automata-based (CA) model based in Metronamica® software, that allows testing different scenarios based on potential land-use policies, environmental suitability and transport alternatives.There has not been, so far, an urban planning tool that accounts for the complexities of this region. CA-based land-use simulations constitute a useful approach to understanding the impacts of urban planning policies and regulations. This tool can help to improve inter-territorial and inter-institutional coordination, which through planning and management policies seek a spatially integrated development, with a long-term perspective.The CA-based model proposed was calibrated to reproduce land-use changes between 2007 and 2016 using different methods and indicators. The model was used to simulate and analyze eight scenarios with different policy directions of transport infrastructure in the future of the region. The results of the simulations reflect the dynamics of territorial occupation. The calibration indices in the experiment indicate a high degree of suitability for the CA Bogotá model, proving its effectiveness and potential as a useful tool for decision-making. The results show that occupation scenarios with restricted developable zones within the city, tend to have the greater dispersion rate in the study area, compared to scenarios where land development plans are promoted in Bogotá, which representing a more compact development.     

Mapping Brisbane’s Casual Creative Corridor: Land use and policy implications of a new genre in urban creative ecosystems

Creative hotspots have become a key driver for urban policies to stimulate social, cultural, environmental and organisational growth of creative and knowledge-based clusters, districts and hubs. However, their functional and spatial characteristics vary due to their different evolving structure as new spaces of economic activity in different contexts. This article points to a consideration of new foci for both land use and urban economic policy through a mapping of formal and informal creative hotspots in Brisbane, Australia. The study found two distinctive development patterns: (a) earlier top-down approaches as instigated by national and international innovation policies, and; (b) recently emerging bottom-up spaces for creativity, knowledge and innovation practices. This study examines how formal creative strategies and emerging informal creative spaces shape cities and urban policies. The methodology comprises online data collection and a review of creative and knowledge strategies and implementation policies. Data was then analysed via multiple mapping techniques illustrating the spatial distribution of creative hotspots, formal and informal formations, scale and land use characteristics. The research findings consolidate our understanding of Brisbane’s creative ecosystem and suggest new urban policy mechanisms to better foster the interrelationship between top-down and bottom-up approaches in cities, that is, between formally planned and large-scale interventions and small-scale organic and informal creative activities.     

Land use regulation and urban land value: Evidence from China

Land use regulation has always been regarded as one of the most crucial means of macro-control of urban growth, which can affect a city’s land values directly and further determine related urban economic well-being. Since the New Type Urbanization Strategy proposed by the government in 2014, China’s mode of urban growth has been transformed from addressing “quantity” to “quality" in the urbanization process. In this case, the regulation of land use by the Chinese government plays a more important role in urban growth. With their planned land regulatory scheme, the various instruments employed by Chinese governments have quite different mechanisms influencing land prices. However, there are no rigorous studies focusing on the land use regulation system and its impact on land values to date, particular in China. This study seeks to explore how land use regulation affects urban land values through the systematic lens. We summarize the main land use regulatory instruments based on the analysis of China’s planned land use system and urban land banking system, including the construction land quota, constraints on the allowed floor area ratio (FAR) of each land transaction parcel, and land supply restrictions. A new dataset based on land transaction data from 2007 to 2016 that covers 286 prefectural cities from the country’s coastal, central, and western regions is used in the empirical analysis. The results show that the effects of the floor area ratio (FAR) on land values are significant and positive, with the residential and commercial land supply ratio being a key factor. Moreover, the results imply that the effects of constraints on FAR and commercial land supply vary between regions. These findings indicate that the Chinese land market is considerably distorted by excessive administrative interventions by local governments, in the stage of urban transition guided, the capable regulatory instruments could play an important role in adjusting urban land prices and hence impact on urban growth.     

Remote sensing-based detection of agricultural land losses around Greater Cairo since the Egyptian revolution of 2011

Over the last four decades, the loss of agricultural land has been observed in Egypt at high rates. However, the highest rates of losses have occurred since the January 25th revolution in 2011. Greater Cairo (GC), which is the largest metropolitan in Egypt, has witnessed a massive loss of agricultural land since the 2011 revolution. However, until now, no study or official report has revealed the volume of agricultural land losses in this region. This study quantifies agricultural land losses around the GC using Landsat satellite images from 2010 and 2018. Supervised classification was performed using the maximum likelihood algorithm in QGIS software. A post-classification comparison method was applied to detect the land use/land cover changes between the classified images; then, the loss of agricultural land was quantified using Arc GIS software. Visualizations of the gains and losses in agricultural land and the spatial trends of agricultural land losses were created using TerrSet software. The results show that 9600 ha of agricultural land were converted to urban use during 2010–2018, which means that the annual rate of agricultural land loss has tripled and now reaches approximately 1200 ha per year. Decay of executive authority, rapid population growth, real estate market speculation and fragmentation of agricultural land were the main driving factors of agricultural land losses during this period. The results of this research may help decision makers understand the current high rate of agricultural land loss. Hence, appropriate strategies may be adopted to prevent future losses of this valuable land.