The building blocks of walkability: Pedestrian activity in Abu Dhabi city center

This study develops an empirical approach that underlines the effect of land use mix and development grain on pedestrian movement in the streets and public spaces of urban neighborhoods. The study begins with the end in mind; it compares two urban sectors in Abu Dhabi city with broadly recognized contrasting levels of pedestrian movement. The research works backward to identify the combination of built environment attributes that result in differing levels of pedestrian activity between the eastern and western sectors of Abu Dhabi city center. Using Geographic Information Systems maps/data files, direct observations, and field metrics, the study computes various indices related to land use mix, density, and street connectivity for Abu Dhabi central business district. The findings of this study highlight the land use, spatial and street network configurations that enhance pedestrian activity in urban centers. From a local perspective, the research outcome would inform future visions aimed at transforming the city of Abu Dhabi into a global metropolis that provides its citizens and visitors with unique and vibrant urban settings conducive to intra- and inter-neighborhood walkability.     

Space syntax analysis of tourists’ movement patterns in the historical district of Kuala Lumpur,Malaysia

Although many researchers study the walkable environment and physical activities, very few studies demonstrate the important functions of walkable places on tourists’ walking experiences, particularly in Southeast Asian cities. This article evaluates pedestrian networks’ connectivity in Kuala Lumpur’s historic district to support pedestrian tourists’ movement patterns. The methods used in this study are gate observation and space syntax (integration value) analysis. The results indicate that pedestrian movement in the study areas is oriented more to land uses and elements of attractors than to connectivity of walkways. The findings suggest that pedestrian-oriented environments could contribute to the walkability of city centers through the integration of diverse place uses and street activities. The findings can be a useful reference for future urban studies and urban design of walkability to regenerate historical city centers that have lost their importance for tourists.     

Sustainability-oriented configurational analysis of the street network of China's superblocks: Beyond Marshall's model

The duality in China's traffic planning has given rise to the basic unit of urban form and function called the superblock, which is defined and bound by an arterial street network. The street network of China's superblock underpins the coexistence and interaction of global and local movement, the public and daily space, and affects place diversity and local characteristics. However, its configuration remains to be articulated because of the lack of a systematic representation method, and the associations between configuration and performance, cognition and design cannot be determined. This study proposes an improved representation method for the street network of China's superblocks based on Marshall's route structure analysis to explore the configurational characteristics and sustainability of the network. To fit local conditions, this study improves Marshall's route structure analysis from four perspectives, namely, the judgement of relative hierarchy, the node construction principle, and the deletion and addition of the original indicators. The improved method is then applied to calculate and compare the depth, connectivity, and complexity of the street networks of 10 sample superblocks in Nanjing, which are classified into six types by construction backgrounds, each having two scenarios differing by the level of publicity. Results indicate that the types formed in accordance with the “The Capital Plan” of the Republic of China, which presents a combination of fine orthogonal grids and radiations, and by the renewal of the traditional street-and-lane network, which has the “characteristic structure” defined by Marshall, perform best in terms of configurational sustainability. The analysis also reveals that the addition of semipublic streets formed mainly from the bottom up narrows the sustainability gap among the samples. This study provides a tool for elaborate urban study and design and provides insights into the cognitive and practical aspects of China's urban planning and design.     

地块肌理 ——土地划分的形态学

地块肌理是城市土地划分形态的表达。它作为街道肌理与建筑肌理的联系中介,是城市肌理的重要组成部分。本文在明确定义城市肌理与地块肌理的基础上,分析了地块肌理在街块、地块格局和地块三个层次上与建筑肌理、街道肌理的关系,并探讨了增强街道与建筑、建筑与建筑空间关联性的土地划分基本原则。     

中国城市形态与相关城市法规的关联性研究——以南京市为例

城市形态被描述为在特定的地方,受到社会、经济、政治、环境等因素综合影响的产物,尤其受到来自于内外部经济发展动力和城市法规的影响与控制。聚焦中国城市法规,以南京市为例,本研究首先梳理了国家、省级及地方城市的相关法规条文,对涉及城市形态的划分为直接相关、间接相关和不相关三类,并总结出这些条文中对城市形态的规定,包括土地使用、建筑布局等强制性规定和城市景观组织等引导性规定。最后通过案例验证,在建立形态法规理论模型和空间关联评价图表的基础上,采用对比分析法,从城市街区平面形态、地块建筑布局形态及街道界面形态等方面,对案例的实际现状与符合法规的理论模型进行图示比较,并结合关联评价图表分析城市形态和法规的关联性。本文研究验证了城市法规对城市形态的关联影响,不仅对我国相关城市法规和城市设计规定的修订具有参考价值,而且对提升城市环境质量具有理论与现实意义。     

高密度沿海地区洪涝风险评价与适应性规划策略 ——以深圳湾地区为例

气候变化背景下，高密度沿海城市受 到风暴潮和极端降雨引起的洪涝灾害冲击。文 章基于韧性理论构建城市空间洪涝风险指标 体系，制定该评价框架的实施路径；基于水文 软件Mike21、GIS平台及其空间网络分析插件 sDNA，复合“天鸽”台风风暴潮与极端降雨情 景，整合深圳湾地区的路网和土地利用进行危 险性、暴露度、脆弱性和适应能力等多源数据； 通过GIS栅格计算得到各要素层分析及洪涝风 险评价可视化地图，结果显示，潮、洪、涝突破 刚性标准加剧了危险性，高密度城市环境增大了 危险区域的暴露度，路网和土地利用布局具有 一定脆弱性，需完善应急疏散和避难场所规划以增强适应能力；根据评价地图识别高风险片区，从路网和土地利用等城市空间物质要素出发， 提出应对洪涝灾害的适应性规划策略。     

基于凸边形地图与轴线地图的城市公园空间组织分析

城市公园空间组织关系极大地影响着公园中的游人分布与使用者的游憩体验。城市公园空间组织相关研究能为城市公园设计、游憩活动与设施布局及游人量管理提供依据与直接指导。但现有研究多在局部层面与定性层面讨论公园的空间组织特征,缺少全局层面与定量层面的思考。基于空间句法理论的凸边形地图与轴线地图分析方法,文章探索了城市公园空间组织关系的分析方法。并以上海黄兴公园为例,计算了其整合度与连接度数值。     

Experimental investigations of the indoor natural ventilation for different building configurations and incidences

This paper presents an experimental investigation of the indoor natural ventilation in terms of wind pressures on the surfaces of cubic buildings of a street located within a high density urban area. Wind tunnel tests over 1:100 scale models for four typical building patterns of a highly populated urban area have been carried out. The variables of the experiments were the building configurations and the incident wind direction. The experimental data are presented in terms of wind pressure coefficient measured on the surfaces of the buildings. The study results gave the evidence that buildings configuration and wind direction are very important factors in determining the induced natural ventilation within urban domains since they characteristically influence the flow yielding differences in wind pressures.     

Economic Basis for Linking Jobs and Housing in San Francisco

Although many have written about urban sprawl, few have sought to measure it. In this article, we present several quantitative measures of urban form and compute these for neighborhoods of varying age in Washington County, the western portion of the Portland, Oregon, metropolitan area. Our results suggest (1) neighborhoods in Washington County have increased in single-family dwelling unit density since the 1960s; (2) internal street connectivity and pedestrian access to commercial areas and bus stops have improved since the early 1990s; (3) external connectivity continues to decline; and (4) the mixing of land uses remains limited. We conclude that while several measures appear to be improving, Portland's war on sprawl is not yet won.     

In-between spaces and social interaction: a morphological analysis of Izmir using space syntax

This research tackles the intermediate spaces between buildings and the street, by examining the definition and importance of spatial configuration in relation to urban morphology and social relations. It also analyses how the organisation of in-between space affects social interaction in different urban forms. To understand the complex relations and socio-spatial structure of the city, it is important to use mixed methods. This research utilises various methods to focus on three dissimilar urban morphologies in Izmir, Turkey. Two inner city quarters and one modern housing estate of middle- and high-income groups are compared using space syntax analysis and snapshot observations. These neighbourhoods are selected according to their syntax measures from more integrated to segregated neighbourhoods in the axial analysis. And for a detailed zoomed-in analysis, similar diameter areas are covered for observations. Subsequently, activity patterns are observed at different times of the day, one weekday and one Sunday in three cases. In each neighbourhood, syntactic measures of all selected streets are correlated with these recorded activities. This study reveals that connectivity of streets is important for supplying niches that trigger long-duration activities and social interaction. In modern estates, stationary activities are not correlated strong enough with movement as it is in inner city neighbourhoods. Additionally, in-between spaces increase the frequency of social interaction and co-presence of people particularly in more integrated areas. However, this is only one element in developing sense of community. Further research is needed especially in correlating space syntax with environmental issues, as well as people’s behaviour.     

Concentration and flow distributions in urban street canyons: wind tunnel and computational data

The goal of this paper is to present bluff body flow and transport from steady point sources of pollutants, or chemical and biological agents in an idealized urban environment This paper includes ventilation behavior in different street canyon configurations. To evaluate dispersion in a model urban street canyon, a series of tests with various street canyon aspect ratios (B/H) are presented. Both open-country roughness and urban roughness cases are considered. The flow and dispersion of gases emitted by a point source located between two buildings inside an urban street canyon were determined by the prognostic model FLUENT using four different RANS turbulent closure approximations and in the model fire dynamics simulator using a large eddy simulation methodology. Calculations are compared against fluid modeling in the Industrial Meteorological Wind Tunnel at Colorado State University. A basic building shape, the Wind Engineering Research Field Laboratory building (WERFL) at Texas Tech University, was used for this study. The urban street canyon was represented by a 1:50 scale WERFL model surrounded by models of similar dimensions. These buildings were arranged in various symmetric configurations with different separation distances and different numbers of up- or downwind buildings. Measurements and calculations reveal the dispersion of gases within the urban environment are essentially unsteady, and they are not always well predicted by the use of steady-state prediction methodologies.     

充分利用规划土地资源，塑造特色城市景观——以《烟台经济技术开发区“海视角”规划》为例

在当前土地宏观调控的背景下,如何利用数量不多的土地资源,塑造独特而富有魅力的城市景观是许多城市在思索的问题。结合烟台经济技术开发区海滨地区的规划实践,通过城市特征控制、活动引导、商业业态引导、街道空间控制等方面的研究,整合滨海岸线资源,寻找在当地现有资源条件下打造城市滨海景观特色体系的途径,塑造独特的“海视角”城市景观,构筑个性化城市滨海轮廓线。     

基于GIS和CFD的城市街道通风廊道研究——以武汉为例

改善通风的城市形态因素可以分为建筑和道路2个方面。建筑形态的通风评价主要采取综合迎风面积密度方法,将城市建筑环境转化为具有数值属性的栅格,从而提取城市建成区的通风廊道,但是该方法忽略了城市重要的通风路径——城市街道。以街道的朝向为主要评价对象,挖掘线状要素城市道路的通风廊道,作为建筑形态通风廊道划分方法的补充。根据通风潜力随夹角的变化规律,利用地理信息系统(GIS)的空间分析技术进行街道的通风潜力评价,在综合迎风面积密度密集的区域,存在通风潜力较高的城市街道。     

Overcoming flaws in permeability measures: modified route directness

Increased levels of walking have been associated with a range of individual and societal benefits, including reductions in energy use and greenhouse gas emissions, and improved public health. Recent scholarship has sought to provide evidence that good street connectivity encourages walking, and though some correlation is evident, the statistical significance of these studies is generally weak. This paper asserts that the most commonly used methods to measure street connectivity, intersection density and block length, are weakened by random variation, and more significantly, utterly fail to detect street patterns. An alternative measure, modified route directness, is introduced, and shown to be capable of measuring the impact of street pattern on permeability. A more effective measure of connectivity could help demonstrate the correlation between street connectivity and walking, enabling stronger arguments for changes regulatory activity and public investment that supports improved connectivity.     

A simple method for designation of urban ventilation corridors and its application to urban heat island analysis

This paper describes urban wind ventilation mapping, using the concept of “building frontal area index”, and uses the Kowloon peninsula of Hong Kong as an example of a dense, sub-tropical urban environment where ventilation is critical for human health. The frontal area index is calculated for uniform 100 m grid cells, based on three dimensional buildings in each cell, for eight different wind directions. The frontal area index is then correlated with a land use map, and the results indicate that high density commercial and industrial areas with large building footprints had higher values than other urban land use types. Using the map of frontal area index, the main ventilation pathways across the urban area are located using least cost path analysis in a raster GIS. Field measurements of urban winds confirmed the significance and functionality of these modelled ventilation paths. Comparison of the pathways with a map of the urban heat island suggests that ventilation is a key parameter in mitigating heat island formation in the study area. Planning and environmental authorities may use the derived frontal area index and ventilation maps as objective measures of environmental quality within a city, especially when temperatures in the inner city are a major concern.     

城市空间易行性及其对老年友好城市建设的启示:以香港为例

城市空间易行性是建设老年人友好城市必须考虑的环境指标。易行空间促进步行和体能活动,对老年人的身心健康有益。本文选取居住区密度、道路联通性和用地混合性三个指标测度香港城市空间的易行性,发现城市中心区(港岛和九龙)的空间易行性明显高于新界。相关性分析指出易行性与人口密度和第三产业就业率存在正相关,与家庭收入和地块面积存在负相关。通过专家访谈,本文分析了不同空间易行性背后的规划思路。早期城市规划推崇的小地块发展模式使中心区地块面积细碎、街道狭小,促进了居住密度和用地混合度,这是造成易行性高的主要原因。然而,这同时造成了环境污染和公共卫生隐患,对老年人身心健康不利。文章指出,未来城市规划要在地块划分的面积与多样性之间求得平衡。定量测度需结合其他研究方法探讨完善步行空间、提高宜居性与老年人幸福感的对策。     

基于空间句法的江南古镇步行空问结构解析——以同里为例

运用空间句法理论分析江南古镇同里的步行空间结构及演变过程,探讨古镇空间形态的自组织法则对土地使用和步行活动的影响。研究发现:(1)外围交通环境的变迁是影响古镇步行空间结构演化的重要因素;(2)步行网络的整合度与外来游客步行通行活动的相关性总体上大于本地居民,不规则的步行网络和层次分明的街巷模式对观光路径选择仍发挥着积极作用;(3)步行网络的整合度与本地居民逗留活动的相关性总体上大于外来游客,居民的户外交往活动受空间可达性影响,并与游客观光活动之间存在着既相互吸引又相互排斥的复杂互动过程。     

城市建设强度与热岛的相关性——以重庆市开州区为例

城市建设强度是城市热岛形成与演变的主要驱动因素,为了揭示两者之间的量化关系,以重庆市开州区为例,在用地地块、规则网格和建筑斑块3个空间尺度上,使用ArcGIS提取地表温度(LST)与建设强度指标,利用SPSS分析其相关性并构建多元回归模型。结果表明:用地地块尺度上,LST与绿化率、建筑密度和容积率之间均呈现显著的负相关,与建筑底面积和总建筑面积之间均呈现显著的正相关。规则网格尺度序列上,LST与建设强度各指标之间的相关性系数随网格面积的增大而增大,在840m网格时达到最大值;总体上LST与绿化率之间呈显著的负相关,与建筑密度和容积率之间呈显著的正相关。建筑斑块的尺度上,LST与建筑层数之间有显著的负相关关系,与总建筑面积之间有显著的正相关关系。城市建设强度直接或间接影响了城市热岛的形成与演变,而相关分析发现,建设强度指标并非都与LST之间呈正相关关系,这表明城市热岛除受建设强度的影响外,还受区域气候、城市形态、城市性质、交通方式以及建筑材质与色彩等多种因素的协同影响,是一个非线性的复杂过程。     

关于澳门建筑条例对住宅可建面积及建筑形态制约的分析

澳门人多地少,新建住宅量少,增加建筑面积是社会上对住宅的实际需求。虽然澳门在规划和建筑管理中没有设定具体建筑面积指标,但是建筑条例对住宅可建面积的设定有一系列严格的控制。文章通过阐述澳门住宅建筑面积的形成机制、高度等级、地段种类、街影条例、76°角面限制等,分析控制建筑面积的关键要素;并通过举例分析关键指标之间的关系和对建筑面积、形态的影响,提出修订建筑法规、采取低覆盖率高地积比、适当拓宽街道等合理增加澳门住宅面积的思路和建议,力求为建筑和规划专业人士、城市开发和管理者提供参考信息和思考空间。     

Fragmentation and internal disturbance of native vegetation reserves in the Perth metropolitan area, Western Australia

Remnant vegetation in metropolitan areas tends to be highly fragmented and affected by disturbances from the urban environment. A rapid survey in 71 nature reserves in the metropolitan of Perth noted surrounding land uses, types of disturbances, rated the level of weeds, rubbish, formal and informal walking paths and fire influence, and estimated vegetation condition. These data were analysed against information on reserve area and shape, connectivity to other native vegetation, period of patch encapsulation, distance from the city centre and local population density to reveal patterns of fragmentation and disturbance in the metropolitan area.Smaller reserves occurred in the highly populated inner metropolitan area, and these reserves displayed high levels of fragmentation, higher levels of weed infestation and path density and low vegetation condition. Reserves were larger, with high levels of connectivity and with less weed cover and higher vegetation condition in the outer metropolitan area. The research highlighted that whilst reserve attributes are largely set in inner urban areas, planning is required in outer metropolitan areas to ensure patches remain well connected and of optimal size and shape. Inner metropolitan reserves should also be preserved and managed, as they are highly valuable for representing the vegetation types that once occurred there, and for providing natural areas for inner city residents.