关键词： urban natural ventilation potential   hydrological simulation   airflow DEM   local climate zone  

摘要： Urban wind environments are closely related to air pollution and outdoor human *** urban natural ventilation potential(NVP)is an important factor in urban planning and ***,for ventilation studies on urban scales,neither macroscale numerical simulations(i.e.,WRF,MM5,etc.)nor microscale computational fluid dynamics(CFD)simulations can conduct efficient *** on the similarity between water flows and airflows,an efficient approach is proposed in this paper to map the urban *** integrating the urban terrain model,urban form model,and prevailing wind pressure model,an airflow digital elevation model(AF-DEM),which represents the resistance to airflow and can be used for a hydrological simulation,is generated and applied to evaluate the urban airflow patterns under different terrain,urban form and ambient wind *** objective was to develop a simulation platform that can efficiently predict the distribution of natural ventilation corridor and *** stream network calculated through the simulation is regarded as potential ventilation corridors within the city,and an index calculated from the coverage rate of wind corridors(CRW)is proposed for evaluating the relative *** Nanjing as a case study,8 AF-DEMs based on different wind directions and wind speed conditions are generated,and their corresponding ventilation corridor maps are *** results are in good agreement with the empirical evidence,indicating that the hydrological model,though a rudimentary approximation of the actual airflows,was effective in revealing the natural ventilation corridor and characterize the relative ***,the implementation of this novel method is simple and convenient,and it has great application potential and value in urban design and management.

关键词： 城市想象   民族国家   现代文学   问题场域  

摘要： 城市和民族国家既是实体性的,也是观念性的。中国现代文学的城市想象研究,需要超越只有一个城市和只有一个乡村的观念模式,对现代性和文化视角的阐释限度有所认识,重视发掘城市形象的多义性和流动性。城市与民族国家构成了一个"问题场域",看待、想象城市的方式常常带有民族国家隐喻的性质。城市想象与民族国家观念能够相互照亮。民族国家观念的表达对城市有着自己的偏好和选择,那些处于内忧外患中心地带的城市,那些被域外文明强势嵌入的城市,或被寄予民族国家崛起厚望的城市,是民族国家话语的聚集地与争讼场。其中,国都、租界城市的文学想象尤其受到民族国家观念表达的青睐。研究中国现代文学的城市想象,需要抓住两个身份,即城市的身份和作者的身份,并引入城市互观的思路和跨国、跨文化的视野,由此拓展城市想象与民族国家研究的空间。

关键词： 海外汉学   都市研究   地方性   文本现代性   情  

摘要： 通过选取自2015年出版的六部专著,本文旨在总结与分析海外汉学界在中国都市研究领域的三个研究新路径:地方性、文本现代性与"情"。这三个各自独立却互相关联的路径也可以被认为是理解中国现代性的三个角度。海外研究者创制了包括世界格局、国家叙事、地方经验、家族生活、个体境遇等涵盖大小领域的理解中国现代性的新范式,近来英语学界的都市研究丰富了我们对于自晚清以来中国现代性的独特性与复杂性的认知。

ISBN: (纸本)9787208167865

关键词： Green infrastructure   Nature-based solutions   Urban sustainability   Urban agriculture   Urban nexus   FWE nexus framework  

摘要： The interactive dynamics in the food, water, and energy system as a nexus (FWEN) are critical to the sustainable development of global cities, and they can be mediated by green and blue infrastructure (GBI) in the urban area. Here we provide a comprehensive literature review to examine how GBI affects FWEN in urban centers, an area which is currently understudied. In order to do this, we undertake a systematic review of the literature using a meta-analytic approach and topic modelling. Based on our synthesis, we develop a conceptual framework of the key links between urban GBI and FWEN and the direction and magnitude of the relationship. We found that GBIs can benefit food supply, energy saving, and climate change mitigation but at a price of food safety and water contamination. Well-designed urban construction can help curb the negative effects. Therefore, we need to make deliberate and integrative policy to link GBI with each element in urban FWEN. Moreover, the focus of studies on GBIFWEN links is also heterogeneous across cities: urban agriculture and food security are priorities in cities located in Africa and Asia as well as in lower income and larger cities (but not metropolitan areas), while the cooling effect of green space has been a focus for cities of middle or high income. Finally, current research focuses on isolated analysis, lacking integrated studies needed for decision making supporting tools. While isolated analyses lead to connectivity failures and can result in adverse impacts, integrated analyses can identify interdependencies of environmental resources between parts of a cycle and across different scales, which can increase resource efficiency and minimize environmental degradation. Therefore, our key findings point out the importance of linking the effects of GBI on each component of FWEN in both research and policy making. (c) 2021 Elsevier Ltd. All rights reserved.

关键词： Urban drainage   Effective impervious area   Runoff coefficients   Sewer systems   Paired rural/urban catchment   Hydrological modelling  

摘要： The expansion of built-up areas within urban and peri-urban river catchments has the potential to increase flooding. Hydrological modelling of these catchments is an important tool to analyse and manage the increasing flood hazard, but it requires an understanding of the areas contributing to runoff from the urban parts of the catchment. This is difficult as in many catchments fine resolution data is not available and the connectivity of the impervious areas, sewer networks and the drainage network are not well understood. In this research, we present a novel approach for calculating the separate and combined sewer fractions for an urban river catchment and use these fractions to improve hydrological modelling of the catchment. The fractions are calculated using monthly runoff coefficients from paired rural/urban catchments, with the procedure carried out for 20 highly urbanized catchments within the UK. The calculated fractions have been compared with the OS MasterMap high-resolution land use data set and also verified against results obtained with the standard method of using hourly rainfall-runoff data in an event-based approach. Hydrological modelling using the physically-based Shetran system demonstrates improved results using the approach developed here. For urban and peri-urban catchments without fine resolution sewer and hydrological data, it is recommended that this new method should be applied before detailed hydrological modelling of the catchments is undertaken in order to evaluate the flows to the drainage network and determine the impact of urbanisation on the water balance.

关键词： Radar data   Conditional merging   Rainfall nowcast   Lagrangian persistence   Urban flood forecast  

摘要： Accurate Quantitative Precipitation Forecasts (QPF) at high spatial and temporal resolution are a perquisite for urban flood prediction. Commonly Lagrangian extrapolation of the rainfall patterns recognized by radar data, forms the basis of such forecasts for the near future (up to 2 h lead time) - referred here as nowcasting. Nevertheless, due to the intermittent nature of the rainfall at such fine scales, the predictability of storms is limited to about 20 min. The predictability loss is caused mainly by the inability of the radar to capture the true rainfall field and because the Lagrangian Persistence is unable to model the temporal evolution of the rainfall field. In this study we focus on the first problem, on how to extend the predictability limit of rainfall at such scales by improving the rainfall field fed into the nowcast model. To overcome the errors associated with the radar intensities, merging techniques between radar and gauge measurements are advised. Among different employed techniques (mean field bias, kriging with external drift and quantile mapping based correction) the conditional merging between the radar and rainfall-gauge measurements seems to capture at best the spatial and temporal patterns of the rainfall at the desired fine scales (1 km(2) and 5 min). Moreover, when fed to two nowcast models, the conditional merging doesn't only increase the predictability of storms from 20 min to longer than 1 h, but as well it improves the agreement of radar based QPF with the gauge measurements. The results are drawn from 110 events observed in the period 2000-2018 by the Hannover Radar (Germany) in an area with a radius of 115 km, where 100 recording gauges were available. As the urban hydrological models are commonly validated on gauge measurements, nowcasting with conditionally merged data, provides a useful tool for urban flood prediction for lead times up to 1 h.

关键词： Micro-mobility   Smart cities   Systematic literature review   Sustainable transport   Bibliometric networks   Co-citation analysis  

摘要： Micro-mobility is increasingly recognised as a promising mode of urban transport, particularly for its potential to reduce private vehicle use for short-distance travel. Despite valuable research contributions that represent fundamental knowledge on this topic, today?s body of research ap-pears quite fragmented in relation to the role of micro-mobility as a transformative solution for meeting sustainability outcomes in urban environments. This paper consolidates knowledge on the topic, analyses past and on-going research developments, and provides future research di-rections by using a rigorous and auditable systematic literature review methodology. To achieve these objectives, the paper analysed 328 journal publications from the Scopus database covering the period between 2000 and 2020. A bibliographic analysis was used to identify relevant pub-lications and explore the changing landscape of micro-mobility research. The study constructed and visualised the literature?s bibliometric networks through citations and co-citations analyses for authors, articles, journals and countries. The findings showed a consistent spike in recent research outputs covering the sustainability aspects of micro-mobility reflecting its importance as a low-carbon and transformative mode of urban transport. The co-citation analysis, in particular, helped to categorise the literature into four main research themes that address benefits, tech-nology, policy and behavioural mode-choice categories where the majority of research has been focused during the analysis period. For each cluster, inductive reasoning is used to discuss the emerging trends, barriers as well as pathways to overcome challenges to wide-scale deployment. This article provides a balanced and objective summary of research evidence on the topic and serves as a reference point for further research on micro-mobility for sustainable cities.

关键词： Urban   Participatory methods   Transdisciplinary   Living labs   Knowledge production   Experimentation   Food–   water–   energy nexus  

摘要： The sustainability of complex resource systems, such as the food, water, and energy (FWE) nexus, is increasingly threatened by climate change impacts, expanding populations, urbanization, and economic instability. However, while research on the topic has burgeoned, studies focused on solution development and implementation, especially at the urban level, have lagged behind. Against this background, we review the urban FWE nexus literature. We focus on the operationalization of solutions for implementation, and seek to identify opportunities for participatory approaches. Our results suggest that operationalization would benefit from: (1) more fully integrating urban social complexity;(2) extending our understanding of the nexus to include social responses to the impacts of interventions;and (3) ensuring that projects build knowledge that is not only actionable, but also credible, salient, and legitimate. We then discuss the potential of local, transdisciplinary approaches, in the form of urban laboratories, to shift the focus of FWE nexus research towards operationalization. We conclude with five recommendations: (1) knowledge development should extend to implementation;(2) stakeholders should be engaged, and be able to align solutions with the agency to implement;(3) research should move beyond material flows, and focus on the behaviors, habits, and social patterns that underpin urban complexity;(4) FWE nexus thinking should become part of participatory/laboratory approaches;and (5) policymakers should integrate nexus research into municipal strategies and plans.