A user‐based method for rating street trees

Responses to questionnaires completed by 1,174 householders who rated characteristics of their street trees were subjected to factor analysis. The most important factors were general benefits, ground disturbance, disease, safety, seasonal marking, droppings and suckers, which became the basis for scales on which each species could be scored. These scales represent an economical and coherent method which can complement simulation and expert rating systems, for describing householder opinion towards street trees.     

Experimental characterization of various scale hydraulic signatures in a flooded branched street network

ABSTRACT

Understanding urban flood flow repartition mechanisms within street network remains challenging. This paper presents an experimental dataset of water depth and velocity profiles in the Icube experimental rig. The spatial variability of discharge along a street is highlighted. Comparing the water depth gradient orientation and the flow repartition promotes for complex repartition mechanisms at small scales. Comparable unit-discharge values are observed in both large and narrow streets. Interestingly, the intensity of the discharge deviation at the crossroad scale is related with the asymmetry of the velocity profile entering a crossroad. Moreover, discharges at the crossroad and the subdistrict scales show that downscaling of the flow repartition relationship is difficult. At real scale, results show that inflow velocity profile asymmetry may persist on a distance of several street widths downstream of a crossroad. Such distances are insufficient to consider disconnected crossroads as done in the literature to establish discharge repartition relationships.     

城市街道视域景观指数与邻里尺度特征效应

城市街道景观指数提取为城市街景研究量化途径之一。结合已有指数,提出用全景静态图的不同数据类型,分类计算视域景观指数的优化方法;提出基于计算机视觉尺度不变特征转换(SIFT)的关键点邻域尺度区间频数;采用层次聚类分析指数不同的邻里尺度最优簇数、贡献度,确定分布特征重要指数组成;探索不同指数作用于不同邻里尺度的特征效应。研究发现视域景观指数具有不同邻里尺度效应。研究指数中城市街道空间的绿视率和天空开阔度(空间组成层面)、关键点邻域尺度(0,10]和(10,20]区间频数(对象尺度层面),以及色彩丰富度指数(颜色层面)是构成城市街道分布特征的重要特征指数。通过确定不同邻里尺度城市街道特征分布,可以为城市街道空间的景观质量提升、量化管理和城市微更新提供参照。     

Experimental insight for flood flow repartition in urban areas

Modeling floods in urban areas remains a challenge. To understand flow patterns in urban geometries better and constrain models, an experimental rig representing a 1/200 scale urban geometry with various street widths and angles is presented. Measurements of hydraulic variables for flow conditions ranging from moderate to extreme flooding were performed. Over this range, accurate inflow and outflow boundary condition measurements allow the geometry effect on inlet–outlet discharge conservation to be studied for each street. Froude numbers are found to be independent of the total flowrate. Interestingly, the flow distribution among all streets remains comparable over the range of boundary conditions. Moreover, three behaviors have been identified depending on street response as a function of the evolution of the upstream discharge distribution. Future measurements with high spatiotemporal sampling would allow possible coupling of flow features and energy dissipation to be studied at various scales and other flow configurations and district geometries to be characterized.     

Street life and the built environment in an auto-oriented US region

Urban planners and designers believe that the built environment at various geographic scales affects pedestrian activity, but have limited empirical evidence at the street scale, to support their claims. We are just beginning to identify and measure the qualities that generate active street life, and this paper builds on the first few studies to do so. This study measures street design qualities and surrounding urban form variables for 881 block faces in Salt Lake County, Utah, and relates them to pedestrian counts. This is the largest such study to date and includes suburbs as well as cities. At the neighborhood scale, we find that D variables – development density, accessibility to destinations, and distance to transit – are significantly associated with the pedestrian activity. At the street scale, we find significant positive relationships between three urban design qualities – imageability, human scale, and complexity – and pedestrian counts, after controlling for neighborhood-scale variables. Finally, we find that pedestrian counts are positively associated with seven of twenty streetscape features – historic buildings, outdoor dining, buildings with identifiers, less sky view, street furniture, active uses, and accent building colors. This study provides implications for streetscape projects that aim to create walkable places in typical auto-oriented, medium-sized cities.     

Can street segments indexed for accessibility form the basis for housing submarket delineation?

We test an approach to spatial housing submarket delineation using street segment as the spatial unit and using finely grained measures of accessibility derived from spatial network analysis. The underlying idea is that street segment connectivity captures fine variations in homebuyers’ preferences for the location. The advantage of the approach is that it is spatially fine grained; it uses the street segment, intuitively the most fundamental spatial unit for spatial housing market analysis; it allows the use of statistical tests to optimize within-submarket similarities, identifying spatial groups of street segments with the most similar accessibility features; it avoids the predefined arbitrary geographic boundaries usually used in spatial submarket delineation; it increases the variability of accessibility information in submarket delineation, accessibility being the principal spatial determinant of housing price; and it allows for normalized measures of accessibility at different spatial scales making it appropriate for comparative analysis across cities and across time. Using a case study of Cardiff, UK, we compare the results with a market segmentation scheme based on prior-knowledge, notably one relying on building-type classification. We conclude that street layout can be used to efficiently delineate housing submarkets, and that the estimation is very close to the scheme requiring prior-knowledge. It has advantages, however, that make it worthy of further investigation, namely its adaptability, scale-specificity and lower reliance on local knowledge of housing market culture and data.     

健康城市环境测度方法与尺度的差异性研究——以大连市为例

环境与健康日益受到关注,但获取环境要素的方法没有明确的界定。通过不同的测度方法和尺度(400m、800m、1200m和1600m)获取物理环境特征(土地利用、密度、街道连接、可达性、坡度、建设环境、步行道环境、美观与安全)和社会环境(社交活动和社会交往),以及人群健康结果(体力活动、心理和生理层面健康)。通过回归模型探索环境对健康结果的影响,以及不同测量方式间的差异,同时以社会环境为调节变量,控制人口特征。结果显示,在400m尺度下呈现显著结果的建成环境要素最多,但主观和客观测量方式之间关联度并不高。建成环境要素以相同的测量方式在不同的尺度下测量有不同的结果,在相同的尺度下通过不同的方式测量亦会有不同的结果。     

上海市行道树土壤理化性质与树木健康的相关性研究

以上海市70条代表性道路的行道树为研究对象,开展行道树健康评价,并分析土壤理化性质与行道树健康的相关性.结果 表明:大多数行道树处于基本健康状态,20％存在较严重的健康问题;土壤物理性质与行道树健康密切相关,其中行道树健康与土壤容重、砂粒含量极显著负相关,与土壤含水量、总孔隙度、黏粒、粉粒含量等极显著正相关;多数化学性...     

浅议街墙表情的类型

针对现阶段我国城市街道盲目建设引起街道空间特色丧失的现状,从对街道的体验和心理感受出发,研究了街道两侧建筑的表现性,即街墙表情,根据风格分类法,对街墙表情的类型进行了分类研究,对塑造富有魅力的城市街道环境具有指导意义。     

街谷行道树种植对环境热舒适度的影响及适应性设计研究 进展

行道树种植通常被作为改善城市街谷 近地微气候的重要策略,如何发挥行道树对街 谷热舒适度的提升潜力受到诸多学者的广泛关 注。近年来“行道树种植与街谷热舒适度”相关 研究获得了丰硕成果，通过总结梳理可将其归 纳为行道树树木个体形态对热舒适度的调控、 行道树绿带空间配置与街谷热舒适度整体提升 的关联性、适应不同街谷空间形态的行道树种 植设计策略等三个研究主题。在深入分析既有 研究成果基础上，提出了一套改善热舒适度的 街谷行道树种植设计方案技术框架。最后，分 别从建立响应地域气候特征的街谷行道树种植 设计模式、构建街谷环境热舒适度模拟评估导 则、制定街谷环境热舒适度评价标准等方面开展深入讨论，以期为后续城市街谷绿化提升热环境的研究提供思路和借鉴。     

地域特色的现代商业步行街界面设计

阐述了界面在商业步行街中的功能及重要性,探讨了延续地域特色的现代商业步行街界面设计策略,在此基础上,结合西藏山南地区泽当镇商业步行街设计实例分析,指出处于地域文化环境中的商业街界面设计应当继承当地历史文脉,突出地方建筑的艺术特色。     

浅析商业步行街环境景观设计

针对国内商业步行街与国外相比的差距,介绍了当前我国商业步行街的景观现状及存在的问题,并对其进行了分析和探讨,从场所精神、夜景照明、街具小品三方面提出了对策与建议,以期提高城市的整体景观质量。     

人性化商业街空间尺度探讨

结合街道尺度的基本理论、空间错视学的理论,研究了国内外经典商业街案例,结合四川自贡市核心商业街的实例探讨了人性化商业街的尺度关系,为营造人性化的商业街区奠定了基础。     

城市街道活力的营造

在现代功能主义规划思想的主导下,城市的活力正逐渐丧失,城市街道作为城市重要的公共生活场所,是城市活力的发生容器.因此,建立形态良好的街道空间,营造具有品质的街道氛围,开展丰富的街道生活,能创造出人们渴望的街道活力.进而给城市带来生机和活力,增加城市的魅力.     

太阳能路灯的最佳设计方法与工程实践

本文研究了太阳能路灯的最佳设计方法,并结合工程阐述了施工应该注意的要点,对指导太阳能路灯工程设计与施工具有较好的参考价值。     

谈浙江水乡街道建筑形式的空间关系

主要论述浙江水乡五种不同的街道形式，即旱街、一河两街、一河一街、有河无街、前街后河，并通过街道形式阐述浙江水乡建筑、街道、河流之间的空间关系，以促进浙江水乡空间结构的发展。     

从前门大栅栏谈传统商业步行街设计要点

本文通过对北京前门大栅栏的商业步行街改造更新为例,对传统商业步行街的市场定位与设计要点之间进行了有机的联系,指出传统商业步行街的市场定位的重要性,以及在此基础上,提出传统步行街设计的要点。     

基于TracePro软件的多曲面路灯反射器设计

设计了一种新型多曲面路灯反射器,运用AutoCAD软件生成多曲面路灯反射器模型,然后运用最优化理论和TracePro光学软件进行模拟仿真,得到优化的多曲面路灯反射器,并通过Matlab软件对后期光场分布的合理性进行计算,结论为:多曲面路灯反射器的光场分布相对合理,光能利用充分,节约能源,有传统路灯反射器无法比拟的优点。     

Ventilation efficiency of void space surrounded by buildings with wind blowing over built-up urban area

This paper outlines methods for evaluating wind-induced ventilation efficiency in void spaces in built-up urban areas. The indices of ventilation efficiency express quantitatively the ability to deliver fresh upper-tier wind to the lower tiers of void spaces and dilute pollutants emitted therein. The evaluation of ventilation efficiency is based on detailed flow analysis. The scales for ventilation efficiency, (SVEs l, 2, 3, and 6) were originally derived by the authors for room air ventilation and are also useful when applied to the exchange of air in void spaces in built-up urban areas. The other scales, namely local purging flow rate (L-PRF), visitation frequency (VF), and residence time (RT), were also re-defined by the authors for room air ventilation and had been applied for urban street canyons. They are based on detailed flow analysis and can be evaluated more easily with computational fluid dynamics (CFD) than flow modeling experiments. CFD simulation example is used to illustrate the concept of the proposed method and it is not meant to indicate the level of CFD set up for urban flow calculations. The effectiveness of the proposed method will be demonstrated more in future study.