Size structure of urban agglomerations in China:rationality evaluation,patterns, and implications

This paper establishes a diagnostic model for assessing the rationality of size structure of urban agglomerations(UAs) in China. The model is designed to determine from a three-dimensional index including size distribution index(SDI), size compactness index(SCI), and size efficiency index(SEI). The spatio-temporal pattern of size structure involving the studied 19 UAs and its implications are explored. The results indicate that size structure of China's UAs advanced from a low rationality development stage to a moderate rationality development stage in 1995-2015.Among them, the SDI and SEI were reasonably high, and the SCI was relatively low. Spatially, the high rationality UAs were distributed across eastern China, while the low rationality UAs were located in western China. UAs with positive size structure possessed typically a dual-or multicenter urban structure, while UAs with negative size structure usually presented as a single-center structure. The evolutionary trajectories of rationality of size structure of UAs can be summarized as four different stages. Our findings suggest that, in addition to consolidating the status of national-level UAs, the development of regional-level UAs should be promoted. Also, the fostering focus and direction should be oriented toward an UA with dual-or multicenter spatial structure.

Research on the Evaluation of Urban Open Data

Urban open data is the key to the construction of smart city. Through the research on evaluation of urban open data, the concept, types, characteristics and other basic problems of urban open data are systematically summarized. From perspective of “quality”, “opening” and “acquisition”, a complete urban open data evaluation framework and index system is built. And the corresponding weights of evaluation indexes and score and overall rating methods are determined, so as to objectively evaluate the conditions of urban open data, and describe, monitor, guide and promote the construction and development of urban open data.

Study of macroscopic fundamental diagram on Shanghai urban expressway network in China

The macroscopic fundamental diagram（ MFD） is studied to obtain the aggregate behavior of traffic in cities. This paper investigates the existence and the characteristics of different types of daily MFD for the Shanghai urban expressway network. The existence of MFD in the Shanghai urban expressway network is proved based on two weeks＇ data.Moreover, the hysteresis phenomena is present in most days and the network exhibits different hysteresis loops under different traffic situations. The relationship between the hysteresis phenomena and the inhomogeneity of traffic distribution is verified. The MFDs in the years of 2009 and 2012 are compared. The hysteresis loop still exists in 2012, which further verifies the existence of the hysteresis phenomenon. The direct relationship between the length of the hysteresis loop（ ΔO） and the congestion is proved based on sufficient data. The width of the hysteresis loop, i. e., the drop in network flow（ ΔQ） has no relationship with the congestion, and it varies from day to day under different traffic situations.

Study on New Urbanization and Urban Ecological Security Assessment

Taking the relationship between new urbanization and urban ecological security protection as research object, based on pressure -status - response model, taking Gaochun （Gucheng Lake basin） and Zhangjiakou （Guanting Reservoir basin） as the examples, basin ecological security in its new urbanization process was evaluated. Based on the principle of comprehensiveness, representativeness and data availability, evaluation indexes were selected, and index system was established. Mathematical function of evaluation indexes was established, and security index of each evaluation indicator in index layer was determined. Using weighted average method, ecological security indexes in the two areas were obtained. On the basis of comparison and analysis, it is proposed that we must deal with urban ecological security problem in new urbanization process, thereby truly achieving ultimate value orientation of new urbanization construction oriented by people.

Evaluation Index System of Urban Identity

In recent years, with the rapid development of urban construction, the maintenance and creation of urban identity has met unprecedented opportunities as well as problems. In light of lacking related evaluation systems of urban identity planning, this paper makes an in-depth study on the composition system of urban identity, based on which it develops an urban identity evaluation system and then proposes technical methods for index screening and evaluation. Finally, it verifi es the application of an urban identity evaluation index system by using quantitative simulation in the two Chinese cities of Tianjin and Nanjing.

Dynamic evaluation of traffic flows on city roads

This paper presents an analysis of the random fluctuations, deferred conduction effect and periodicity of road traffic based on the basic features of road networks. It also discusses the limitations of road network evaluation theories based on road "V/C". In addition, it proposes a set of theoretical and technical methods for the real-time evaluation of traffic flows for entire road networks, and for solving key technical issues, such as real-time data collection and processing in areas with no blind zones, the spatial-temporal dynamic analysis of road network traffic, and the calibration of key performance index thresholds. It also provides new technical tools for the strategic transportation planning and real-time diagnosis of road traffic. The new tools and methodology presented in this paper are validated using a case study in Beijing.

Optimization for Bus Stop Design Based on Cellular Automaton Traffic Model

Bus is a main component of public transportation,and then the design of bus stop position,size and form should improve efficiency of public transportation.The optimization of bus stop is studied in this paper.According to the observation and analysis of realistic traffic,a micro-cellular automaton mixed traffic flow model with bus stop is established.And then a new evaluation index for the bus stop design is introduced.Finally,an optimized bus stop scheme is obtained by simulation.This research is studied for providing a theoretical basis for the construction of bus stop.

Difference of Urban and Rural Development in Binzhou from the Perspective of Urban and Rural Coordinating

The coordinated development of urban and rural areas is an inevitable trend to break the dual urban-rural structure and promote the coordinated development of urban and rural areas.The statistical data on the overall economic and social development of urban and rural areas in Binzhou from 2006 to 2015 were studied and analyzed,and an urban and rural integrated evaluation index system was established,which was evaluated using principal component analysis.The results showed that the overall level of urban and rural integrated development in Binzhou City is low,but has been rising in recent years;and the urbanrural dual structure gradually weakens.

中国典型城市交通出行特征及未来道路交通演变研究

为建立适合不同城市特点的交通体系,并明确定位汽车在其中承担的作用,文章首先从外部环境和交通工具两大维度出发,建立了表征城市整体交通出行情况的多层级评价体系;并基于一级指标的得分,对选取的9座中国典型城市的交通出行特征进行了聚类分析,确定了城市的不同类型;然后通过多元回归分析,识别了影响城市道路交通的主要因素;最后通过相关因素变化的情景假设,预测了各城市道路交通效率可能的演变情况,并提出了相关政策建议。

美国城市公园评价指标ParkIndex的开发应用与启示

城市公园具有社会、经济、生态和健康等多种效益。对城市公园使用潜力进行科学评价,有利于改善城市公共空间服务水平,对居民生活质量提升具有重要意义。梳理了美国ParkIndex指数开发过程内容和实践,ParkIndex开发主要包括3个过程:ParkIndex原型开发、关键人物访谈和试点测试。最终形成的ParkIndex指数模型包含3个变量,分别是0.804 km(0.5 mile)内公园数量、0.804 km(0.5 mile)内公园总面积和0.804 km(0.5 mile)内公园平均质量指数。随后,在纽约布鲁克林某社区进行实践,研究变量改变对ParkIndex值的影响;并对其应用领域与未来发展方向进行探讨。为我国开发城市公园使用评价体系提出启示:采用定性与定量相结合的研究方法成为趋势;建立完善、科学的城市空间数据库;城市公园使用评价指标体系应具有高适应性和有效性;城市公园使用评价需纳入多方意见,以人为本。

城市轨道交通工程防淹能力评估方法研究

近年来我国城市轨道交通工程水淹事件频发,人民生命财产安全受到威胁。交通运输部在2022年7月修订的《城市轨道交通初期运营前安全评估管理办法》中增加了“工程项目防洪专项论证报告等材料”作为轨道交通新线投入初期运营前的前提条件之一,因此开展城市轨道交通工程防淹能力研究十分必要和紧迫。本文从外部风险、基础防汛能力、防汛预警能力、应急救援能力等方面研究了影响城市轨道交通工程防淹能力的关键因素,利用专家打分法、层次分析法构建了评估指标体系及其权重系数,并根据我国现行法律法规标准规范提出了各指标评分细则,建立了城市轨道交通运营线路防淹能力评估方法,以期为我国汛期城市轨道交通运营安全提供技术支撑。

干旱半干旱地区城市公园绿地空气负离子浓度特征及影响因素

为研究干旱半干旱地区城市公园绿地空气负离子浓度(NAIC)特征及影响因素,以呼和浩特市敕勒川公园为对象,于2020—2021年,每个季节选取晴天、晴间多云为主的天气各10 d,同步监测07:00—19:00时段,5种不同结构绿地(乔草型、乔灌型、乔木型、灌草型、乔灌草型)及对照区(CK)空气负离子浓度及PM10、PM2.5、温度、湿度、风速、大气压强、噪声等环境指标。结果表明:不同结构绿地空气负离子浓度季节日变化有所差异;同一季节,复杂结构绿地空气负离子浓度均值较高,不同结构绿地之间空气负离子浓度均值差异不显著;同一结构绿地,夏、秋季空气负离子浓度均值显著高于春、冬季;不同结构绿地空气清洁度夏、秋季较高,空气清洁度评价指数均值分别为0.58~0.78、0.52~0.80。绿地结构、季节对空气负离子浓度影响为主效应,绿地结构×季节对空气负离子浓度交互作用不显著;除此之外,相对湿度、PM10、PM2.5是影响空气负离子浓度的主要因素。

基于要素的城乡融合识别研究——以重庆永川南大街街道为例

科学理解城乡融合发展状态,对于实现乡村振兴、建立良性的城乡关系有着重大作用。城乡融合的实质是城乡要素的融合,本文从资源禀赋、人口、经济、文化、生态、政治6个方面构建城乡融合水平评价指标体系,并对重庆市永川区南大街街道城乡融合程度加以识别,将南大街区分为高融合度区域(中心城区、小南村)、中融合度区域(大南村、代家店村、黄瓜山村)、低融合度区域(谭家坝村、八角寺村、兴隆村),并针对不同的城乡融合度区域提出未来发展方向。研究可为我国城乡融合发展与乡村转型发展的研究与实践提供借鉴。

中国城市群市政基础设施水平综合评价——基于ARCGIS热点分析

“十八大”以来,国家高度重视城市群内部公共设施服务共享、生态环境共治问题,对城市群基础设施水平研究可以为城市群可持续发展提供科学数据。基于5大城市群市政基础数据(2016-2020年),利用因子分析、莫兰指数、ArcGIS的热点分析工具剖析5大城市群基础设施水平。研究结果发现:珠三角城市群的基础设施水平最高,成渝、长江中游城市群等内陆城市的基础设施水平较珠三角、长三角等沿海城市群设施水平差距较大;城市群的空间集聚性明显,珠三角城市群基础设施水平属于“高高聚类”,成渝城市群属于“低低聚类”;基础设施资源配置方面存在分配不均衡问题。

城市道路塌陷总体风险评估方法研究

为解决城市道路塌陷事件频发问题,分析了道路塌陷成因。运用风险控制理论建立了一套完善的道路塌陷风险评估指标体系,形成了一种城市道路塌陷总体风险评估技术方法。该方法根据风险值的大小制定风险等级和应对措施,可进一步为城市道路塌陷探测工作计划编制提供科学指导。通过实际案例证明该评估方法具有可操作性,能够为城市道路塌陷防控提供技术支撑。

城市群品牌体系评价与形象提升研究——以成渝双城经济圈为例

城市群作为区域经济发展的重要载体,加强其品牌形象塑造,将有助于打破行政区域划分的限制,在更高层次上实现城市品牌符号的竞争,增强城市群的吸引力、传播力、凝聚力和号召力,促进城市经济社会文化的高质量发展。在借鉴相关成熟指标和测量方法的基础上,建构由经济发展、创新能力、宜居水平、文化影响和品牌传播力等5个一级指标、13个二级指标和33个具体指标构成的城市群品牌评价体系,并对成渝双城经济圈内36个市(区县)进行测算。研究结论如下:城市经济越发达,其城市文化发展水平也越高,部分区县文化资源开发存在较大差距;除核心城市外,多数城市的品牌传播力指数较低,表明地方媒介的作用与效能没有得到充分发挥。在此基础上,重点从经济、创新、宜居和文化等四个方面,提出成渝双城经济圈城市群的整体品牌形象提升战略与整合传播策略。

基于粗糙集-云模型的城市常规公交运力配置水平评价

为优化完善城市常规公交运力配置的多层次综合评估指标体系及其等级标准,以便科学评估常规公交运力配置水平,提出了一种基于粗糙集-云模型的城市常规公交运力配置水平评估模型。首先,利用粗糙集理论对指标体系进行筛选,并匹配了相应的等级标准;然后,采用CRITIC方法对指标进行赋权,进而利用云模型算法生成评价标准云和结果云,通过数字特征和云图直观展现评价结果。最后,以青岛市主城区144条常规公交线路为例,对模型进行了验证。结果显示:青岛市主城区144条常规公交运力配置水平目标层综合评价等级为“中等”,在子目标层(公交客流水平、公交线路水平、公交线路发车水平、公交车辆运营水平、公交车辆技术水平)中,评价等级为“中等”及以上的占60%,总体上与目前青岛市主城区常规公交运力配置水平特点相符。研究表明,该模型能实现对城市常规公交运力配置的综合评价,可为城市常规公交运力配置评价体系和评价模型构建提供参考。

城市轨道交通车站系统韧性承载能力评估指标体系研究

城市轨道交通发展迅速,运营环境日渐复杂,其车站系统具有高负载、高频率运营和处于地下空间环境等特点,导致安全风险提升及事故发生。对车站系统韧性承载能力评估指标体系进行研究,旨在准确评估系统韧性,提高车站系统韧性水平。通过分析车站系统韧性承载能力的影响因素和相关调研,构建由102个指标构成的原始指标库,并初步筛选出42个指标。基于车站系统特点,构建DEMATEL-ISM复合模型,对指标进行二次筛选。通过对指标原因度、中心度、区域联通性、初始发出层、最终接收层的分析,建立了四类(27个)指标构成的城市轨道交通车站系统韧性承载能力评估指标体系。研究结果可为车站系统韧性评估计算提供参考。

面向公共交通融合发展的城市地铁运营绩效评价方法

城市地铁是缓解城市交通拥堵、实现交通结构集约化的重要载体,但建设与运营成本大。特别在城市地铁大规模建设的背景下,公交客流颓势愈显。为此,面向城市地铁与公交的融合发展,在考虑地铁建设对公交客流负面作用的前提下,采用SBM(slacks-based measure)模型系统评价城市地铁的运营绩效。进而在连续时间截面下,通过GML(global Malmquist-Luenberger)指数持续跟踪地铁运营绩效的变化趋势。然后考虑城市经济发展、规模发展和私家车竞争等外部因素,利用Tobit模型分析其对城市地铁运营绩效的影响。基于2018—2021年我国31个城市的面板数据,采用含非期望产出的SBM模型测度各城市各年份的地铁运营绩效,发现规模大、客流强度高的城市地铁运营绩效通常更高;除2020年受疫情影响外,其余年份城市地铁运营综合技术效率和规模效率逐年上升,但纯技术效率逐年下降,对现有投入资源的利用率降低。地铁运营无效的城市主要表现为公交客流下降严重,亟须强化地铁与公交的融合发展。采用GML指数测算相邻年份间各城市地铁运营绩效的动态变化特性,发现我国城市地铁运营全要素生产率年均下降2.8%,主要归因于疫情阶段放缓了技术进步。Tobit模型进一步发现城市建成区面积对城市地铁运营绩效具有显著的正向作用。研究结果可在地铁与公交融合的背景下全面定位城市地铁的发展瓶颈,为提升轨道交通在城市公共交通中的引领及促进作用提供理论与方法基础。