流动商贩的分布特征及营业空间界面影响分析——以广州中山大道西路段为例

流动商贩的空间分布有较大的临时性和变化性,但在各种不同因素的影响下,也具有一定的特征性。研究其分布特征和影响因素对从空间上引导该非正规经济的发展具有积极意义,而已有从空间角度出发的非正规经济研究成果较少。本文主要采用实证研究的方法,选取广州中山大道西路段的流动商贩为典型案例,从空间的角度对流动商贩这种非正规经济来进行研究。研究发现,流动商贩的空间分布具有时间、空间和类型构成三个特征。影响其分布特征的空间界面因素包括界面用地性质、权属以及界面空间特征等,揭示流动摊贩空间集聚的根源,为城市的规划管理和建设提供一定参考。     

Local Indicators of Network-Constrained Clusters in Spatial Point Patterns

The detection of clustering in a spatial phenomenon of interest is an important issue in spatial pattern analysis. While traditional methods mostly rely on the planar space assumption, many spatial phenomena defy the logic of this assumption. For instance, certain spatial phenomena related to human activities are inherently constrained by a transportation network because of our strong dependence on the transportation system. This article thus introduces an exploratory spatial data analysis method named l ocal i ndicators of n etwork-constrained c luster s (LINCS), for detecting local-scale clustering in a spatial phenomenon that is constrained by a network space. The LINCS method presented here applies to a set of point events distributed over the network space. It is based on the network K -function, which is designed to determine whether an event distribution has a significant clustering tendency with respect to the network space. First, an incremental K -function is developed so as to identify cluster size more explicitly than the original K -function does. Second, to enable identification of cluster locations, a local K -function is derived by decomposing and modifying the original network K -function. The local K -function LINCS, which is referred to as KLINCS, is tested on the distribution of 1997 highway vehicle crashes in the Buffalo, NY area. Also discussed is an adjustment of the KLINCS method for the nonuniformity of the population at risk over the network. As traffic volume can be seen as a surrogate of the population exposed to a risk of vehicle crashes, the spatial distribution of vehicle crashes is examined in relation to that of traffic volumes on the network. The results of the KLINCS analysis are validated through a comparison with priority investigation locations (PILs) designated by the New York State Department of Transportation.     

New Indices for the Existing City-Centers Streets Network Reliability and Availability Assessment in Earthquake Emergency

During earthquake emergencies in existing city-centers, streets network permits inhabitants to reach safe areas, and rescuers to access damaged zones and help population. However, the network can suffer from blocks due to debris of collapsed or heavily damaged buildings. Understanding urban fabric modifications and classifying elements vulnerability are fundamental steps while dealing with risk-assessment and risk-reduction strategies. This article offers a first quick approach for assessing seismic vulnerability of paths network by considering interferences with building heritage damages. Quick data about existing urban fabric (e.g., buildings typology; streets and buildings geometries) are combined for developing new vulnerability indices for streets network. The earthquake macroseismic intensity is introduced for evaluating probable street blockages and summarizing the overall rating of risks in critical network locations, thus intensity that is not included in other current quick methods for streets-building interference is here taken into account. Risk-reduction strategies based on the proposed indices could minimize the interventions on architectural heritage, maximizing the safety of evacuees. These new indices could be combined with traditional assessment of buildings vulnerability, and evaluations on pedestrians’ and vehicles evacuation flows, for evaluating management strategies.     

西安市交通网络综合通达性研究

以西安市交通网络数据为数据源,利用GIS空间分析技术,选取道路密度、道路服务指数、路网连接度和可达性模型四个指标对西安市交通网络的空间形态、空间分布、距离关系进行多角度分析,并在此基础上,构建了综合评价指标,分析了西安市主城区四级城市道路网络的通达性现状。结果表明:西安市的道路交通网络通达性呈现明显的空间分异,受历史因素、经济政策及自然环境等因素的影响,其通达性空间格局呈现典型的单中心多圈层结构,位于市中心的区域通达性最好,并在北,西,西南,南,东五个方向延展,这五个方向通达性递减幅度较小。研究对西安市交通网络的优化和扩展有一定指导作用,对城市交通网络布局和通达性分析评价进行了一定改进。     

Negotiating "Streets for All" in Urban Transport Planning: The Case for Pedestrians, Cyclists and Street Vendors in Nairobi, Kenya

Abstract:  This paper uses the concept of "streets for all" as the analytical basis to critique the neglect of pedestrians, cyclists and street vendors in transport policy and practice in the city of Nairobi. The paper shows that transport planning in Nairobi has not adequately taken care of informal economy and non-motorized transport such as walking and cycling. This has resulted in competing use of pavements and roads, exposing pedestrians, cyclists and street vendors to insecurity and harassment. The paper calls for inclusive transport planning for multiple street activities, which requires implementing a "streets for all" policy. Such a policy needs to be critically pursued at the level of dealing with the institutional and structural bias in urban transport planning towards motorized traffic and the overall urban development that does not adequately consider the spatio-temporal activity pattern and the life of pedestrians, cyclists and vendors on the streets.     

Exploring patterns of movement suspension in pedestrian mobility

One of the main tasks in analyzing pedestrian movement is to detect places where pedestrians stop, as those places usually are associated with specific human activities, and they can allow us to understand pedestrian movement behavior. Very few approaches have been proposed to detect the locations of stops in positioning data sets, and they often are based on selecting the location of candidate stops as well as potential spatial and temporal thresholds according to different application requirements. However, these approaches are not suitable for analyzing the slow movement of pedestrians where the inaccuracy of a nondifferential global positioning system commonly used for movement tracking is so significant that it can hinder the selection of adequate thresholds. In this article, we propose an exploratory statistical approach to detect patterns of movement suspension using a local indicator of spatial association (LISA) in a vector space representation. Two different positioning data sets are used to evaluate our approach in terms of exploring movement suspension patterns that can be related to different landscapes: players of an urban outdoor mobile game and visitors of a natural park. The results of both experiments show that patterns of movement suspension were located at places such as checkpoints in the game and different attractions and facilities in the park. Based on these results, we conclude that using LISA is a reliable approach for exploring movement suspension patterns that represent the places where the movement of pedestrians is temporally suspended by physical restrictions (e.g., checkpoints of a mobile game and the route choosing points of a park).     

国内外城市职住空间匹配研究综述

职住空间组织是城市内部空间结构的重要组成部分,二者的空间匹配关系对城市空间布局的合理性和城市运行的低碳性具有重大影响。本文从国外和国内两个方面回顾了城市职住空间匹配研究的主要内容及进展,并从基础理论研究、研究内容、研究方法等方面对国内外相关研究进行了对比分析,指出当前国内研究存在的问题和缺陷以及进一步深入研究的方向。     

基于街道尺度的南京市老年人口空间分布演变研究

基于南京市第五次和第六次人口普查分乡镇、街道数据,通过街道和圈层双尺度分析了人口老龄化的程度差异、空间差异以及空间相关性,探讨南京市街道老年人口的空间分布格局,采用热点区演化分析了街道老年人口的时空演变特征。结果显示:①近10年南京市街道老龄化系数总体上呈现"跨越式"圈层蔓延扩散的空间分布特征,处于老年人口成长阶段的街道由分布在中心城区和主城区的交界地带转变为向主城区蔓延的趋势,轻度老龄化的街道分布在中心城区,中度老龄化阶段的街道集中分布在主城区和郊区,重度老龄化阶段的街道以郊区为主。②街道老年人口密度类型为密集区,密度最高的区域位于中心城区,郊区次之,主城区内密度最低。③南京市街道人口老龄化率呈现显著的空间正相关,随着时间的推移,街道人口老龄化在空间上的差异增大,集聚效应减弱,空间上的发展渐趋不均衡。热点区分布呈现"冷-次冷-次热-热"的圈层式空间分布格局。④从历史因素、人口生命周期、城市变迁三个角度分析了影响南京市老年人口分布和演变的主要因素。     

Optimal Sampling Design for Variables with Varying Spatial Importance

It is often desirable to sample in those locations where uncertainty associated with a variable is highest. However, the importance of knowing the variable's value may vary across space. We are interested in the spatial distribution of Received Signal Strength Indicator (RSSI), a measure of the signal strength from a cell tower received at a particular location. It is crucial to estimate RSSI values accurately in order to evaluate the effectiveness of mayday systems designed for rapid emergency notification following vehicle crashes. RSSI estimation is less important for locations where the probability of a crash is low and where the likelihood of call completion is either close to zero or one. We develop a method for augmenting an initial spatial sample of RSSI values to achieve a high‐precision estimate of the probability of call completion following a crash. We illustrate the approach using data on RSSI and vehicle crashes in Erie County, NY.     

交通路网中心性对土地利用强度的影响研究——以青岛市中心城区为例

采取青岛市交通路网矢量数据和 POI 数据，综合运用核密度估计法、地理加权回归模型和多中心性评价模型，从中心性角度解析了青岛市中心城区交通路网与土地利用强度的相关关系。研究表明：青岛市中心城区交通路网的临近中心性与直线中心性结构呈现“中心—外围”模式，中介中心性具有显著的点轴模式；商业、公共服务以及居住用地布局均呈现多中心结构；交通路网中心性与土地利用强度具有较强的相关性且相关关系具有空间异质性；商业用地和公共服务用地与交通路网中心性的相关性高于居住用地。研究揭示了交通路网与土地利用强度之间具有较强的依赖性，为城市规划提供可靠的理论依据，有助于进一步优化城市空间布局。     

从地理空间到复合式空间——信息网络影响下的城市空间

分析了城市在地理空间、网络空间上存在的相互依赖关系以及这二者之间复杂作用关系,说明网络空间并非地理上城市空间功能的简单延伸,也并非现实空间的简单镜像;信息社会的城市空间是一种地理空间与网络空间相互依存、相互交织的复合式空间。城市空间仍然具有重要的地理学意义,地缘上的差异以新的方式体现出来。     

基于GIS的徐州市城乡交通基础设施通达性研究

以徐州市城乡交通网络数据为数据源,利用GIS空间分析技术,选取长度-半径维数、分枝维数、距离可达性、时间可达性和可达性系数5个指标对该区交通网络的空间形态、空间分布、距离关系、时间关系等进行多角度分析。结果表明,徐州市城乡交通网络长度-半径维数呈现明显的空间分异,徐州市区及周边地区交通网络密度最大,其次是东部,西北部县域交通网络密度最小,分枝维数和长度-半径维数的空间分布基本一致。区内各节点的时间和距离可达性均随距离徐州市区的增大而增大,通达性高于全区平均水平的节点有徐州市辖区各节点,接近全区平均水平的节点有邳州市、沛县和睢宁县,而丰县和新沂市的通达性水平则低于全区平均通达性水平。     

我国城市街区单元平面形态的演替:现状、动因及规律

论文基于相关城市的土地利用数据对城市街区单元平面形态的变化规律进行理论模拟和定量分析。研究结果表明,在外向型城市扩张模式或内向型城市更新模式下,城市街区单元的空间尺度都有明显的增大趋向,区域范围内街区单元的数量也相应减少。造成这一趋势的主要原因在于在经济和社会需求驱动下的建设模式,以房地产企业为代表的社会力量成为城市街区成型的主导力量,基于成本-收益等经济利益考虑,企业倾向于扩大开发项目的空间体量,从而造成了城市街区单元尺度的增大;这一变化本身也深刻影响了城市的居民生活和产业活动。     

基于高速公路交通流的江苏省城市空间关联特征

在江苏省高速公路网络2012年12月OD流量数据和通行时间数据支撑下,本文从县市尺度出发,在对城市空间关联的节点、路径和组团等要素分析基础上,尝试勾绘关联特征的基本图示。结论如下:①城市节点分布有一定的等级性,且节点重要性本身与其社会经济发展状况或在高速公路的功能定位有关。②单一组团或近邻组团以"中心城市+关联节点"进行关联,且城市间的通行时间基本在1小时内,而中长距离的双核心或多核心的组团则以中心城市作为联系基轴建构,且通行时间在1-3小时之间。③综合节点、路径和组团等要素勾绘的城市关联特征模式包含苏北系统、跨江系统和苏南系统,且该模式昭示以"多板块协同发展"的思路规划区域发展战略可作为优先考虑的方案。     

基于POI大数据的资源型城市功能区识别方法与实证——以辽宁省本溪市为例

精准识别城市功能区对于优化协调城市人地系统，完善城市规划及促进城市可持续发展具有重要意义。选取公众认知度和地物一般面积对行业POI数据核密度进行加权，构建城市功能区定量识别方法，以本溪为例，输出城市功能区分布图并开展分析。结果表明：①考虑公众认识度与一般面积的核密度加权方法具有更高的实际性和准确性；②本溪市中心城区受地块大小、交通等因素影响，形成“多中心”组团、“单一-混合”功能区协同发展的空间格局。应进一步完善本溪新城区公共服务体系、优化旅游业产业链条，推进资源型城市转型进程。     

Sense and the city: exploring the embodied geographies of urban walking

Within UK pedestrian policy, walking is promoted as a sustainable mode of transport that benefits both the body and mind. However, much policy discussion assumes all walking to be the same and a largely self-evident means of transport, whilst many academic engagements with walking are highly abstract theorisations that lack any systematic empirical exploration of actual pedestrian practices. As such, there is little that unpacks the experiences of those who navigate, negotiate, and traverse the city streets in their day-to-day lives. In contrast, this paper aims to situate and understand the practice of everyday walking in the unfolding experiences of urban pedestrians. Walking is positioned and understood as a socio-technical assemblage that enables specific attention to be drawn to the embodied, material and technological relations and their significance for engaging with everyday urban movements on foot. The analysis draws upon in-depth interview and walking photo diary data from participants in the inner London boroughs of Islington and Hackney. Particular analytic attention to the different styles and conventions of urban walking and how these are intimately linked to bodily senses and the materiality of the city provides an opportunity for creating an increased engagement between urban and pedestrian policy and urban and social theory.     

城市犯罪中的公共空间盲区及其综合治理

发生在城市公共空间的犯罪案件,数量大、类型多,造成的危害往往波及整个城市社会和公众,对公共空间盲区的综合治理委实是城市犯罪防控的一项十分重要的社会工程。本文分析了城市公共空间的各种空间特性,指出公共空间功能面向的广泛性、人员物资的流动性、空间结构的开放性和空间归属的无主性等是造成大量空间盲区的重要原因。根据外部形态和内部结构的不同,本文将公共空间分为封闭型、相对封闭型和非封闭型等3种类型,并分门别类地阐述了综合治理各种公共空间盲区的主要措施和工作重点。     

基于道路网络的犯罪空间聚集特征研究

由于目前犯罪空间聚集特征研究的单元主要是地点、街区、巡逻区等,但是许多警务工作是沿道路网络开展的,因此有必要研究犯罪在道路网络上的空间聚集特征。本文以路段为分析单元对浙江省某地2011-2014年发生的16787起盗窃类犯罪进行了研究。通过分析,发现:1在道路网络中存在犯罪热点路段;2犯罪在路段上具有聚集性,少部分犯罪热点路段聚集了大部分犯罪,如19.86%的犯罪热点路段聚集了53.42%的犯罪;3犯罪热点路段在道路网络中也具有空间聚集性,主要聚集在类型为住宅区、大学、商业区等7个区域。根据犯罪在道路网络上的聚集特征,警察部门能优化相关警务工作,科学分配警力资源,从而提高治安防控、犯罪预防、侦查破案等能力和效率。     

贵阳市道路拥堵状态时空分布规律研究——基于出租车GPS大数据

利用贵阳市出租车GPS数据,建立ArcGIS空间模型计算路段平均行程速度,以空间数据库和ArcGIS空间分析为技术支撑,分析道路拥堵状态的时空演化规律。结果表明：①路网平均行程速度的时间分布特征具有高度相似性,且工作日与休息日分布差异大;②工作日高峰时段拥堵区域分布主要以老城区为主。休息日总体上呈现离散分布趋势,且晚高峰时段交通状况比早高峰更拥堵;③工作日早高峰交通拥堵路段呈由中心核心区逐渐向外围扩散的趋势,晚高峰呈由外围向中心核心区聚拢趋势。休息日早高峰不明显,晚高峰呈现由外围区域向内聚拢趋势。基于上述时空演化规律,从城市功能分散、城市道路网、城市空间发展、城市公交系统等方面讨论了贵阳市城市道路交通优化调整对策。     

城市规划视角下西安市主城区住宅空间结构演变研究

近年来,住宅市场的空间分异逐渐受到学界关注。本文以西安市主城区为研究区域,以2003年至2009年区内住宅资料为基础数据,分析了西安市主城区住宅空间结构的动态演变规律,并从城市规划视角对住宅空间结构演变机制做以探究。结果认为:西安市主城区内住宅空间结构呈现出数量上向轴线和板块集聚、价格上向多核均衡演变的趋势。住宅空间结构的演变受城市规划的空间战略、产业布局、交通建设和设施配套等影响较大。科学的城市规划能够引导住宅结构逐步优化,使之从单一极化结构向多极多层次的网络化均衡结构演变。