Cities under Siege: Urban Planning and the Threat of Infectious Disease

Many analysts argue that the potential for a natural, accidental, or nefarious infectious disease event to have a dramatic impact on urban areas in the United States and abroad is growing. After reviewing the justification for this position, this article considers what cities should do to prepare for a major disease event. Recognizing that prevention and preparation receive insufficient attention, we recommend that planners seek out and work with both public and private sector groups with roles in disaster planning; design land and transportation planning information systems to aid and support decision makers during crises; encourage greater self-sufficiency in food production and consumption; assist in the design of humane, realistic evacuation strategies and routes; and consider the effects of their day-to-day recommendations on disease risk and response.     

Lowering the outdoor temperature in high-rise high-density residential developments of coastal Hong Kong: The vegetation influence

This paper investigates the impact of on-site variables on the influence of vegetation in lowering outdoor temperature. The study uses six critical on-site variables such as surface albedo, sky view factor, altitude, shrub cover, tree cover and average height to floor area ratio to carry out analysis in five data sets. The climatic parameters and physical characteristics were measured and surveyed, respectively in 216 stations in high-rise high-density residential developments of coastal Hong Kong. The data set is mainly categorised into peak summer clear sky days (PSCS-days), peak summer partially cloudy days (PSPC-days) and late summer days to address the issues related to cloudy sky conditions in Hong Kong. The trend analysis shows that at a lower sky view factor, ranging from 0.1 to 0.25, shrub cover as low as 10–15% in a 1000 m² open area is more effective in reducing outdoor temperature than the same level of tree cover in a location with a higher sky view factor (0.4 or above). The regression models used in this study were able to explain the influence of on-site variables on vegetation in lowering the outdoor temperature within the respective urban settings. In high-rise high-density environments, on-site variables such as sky view factor and altitude have a substantial impact on the influence of vegetation in lowering outdoor temperature. However, off-site variables such as high urban density and anthropogenic heat could negate the behaviour of sky view factor and altitude. The study suggests that increasing the tree cover from 25% to 40% in the pocket parks in coastal area residential developments of Hong Kong could reduce daytime urban heat island intensity (UHI) by further 0.5 °C.     

局地气候区与昼夜城市热岛效应的耦合关系研究

针对局地气候区框架下城市地表热环境昼夜差异研究的不足,本文基于机载LiDAR、IKONOS-2等多源遥感数据实现了局地气候区分类,重点分析了局地气候区与城市地表温度之间的响应关系及其昼夜差异.研究结果表明局地气候区类型地表温度存在显著的昼夜差异.在白天,大型低层建筑区LCZ 8地表温度最高,水体LCZ G地表温度最低.在夜间,裸土／沙土LCZ F为最冷的局地气候区,而水体LCZ G呈现了最高的地表温度.随建筑高度的升高,紧凑建筑类型区和开敞建筑类型区白天地表温度呈现下降的趋势,而夜间则表现出相反的规律.局地气候区类型的热属性在夜间(85.8％)比白天(79.5％)更容易区分.不论白天与夜间,开敞高层建筑区LCZ 4和水体LCZ G分别为建筑类型区和土地覆盖类型区中与其他局地气候区地表温度区分更明显的类型.     

城市热岛作用下办公建筑冷负荷的影响因素分析

通过对收集布置在天津市市区的5个温度监测点和位于市郊的西青气象站2003年夏季的气象资料进行分析比较。发现天津市区的平均热岛强度在3-5℃左右。利用能耗模拟软件EnergyPlus分析了建筑热敏感性以及夏季室内设计温度不同时城市热岛(UHI)对办公建筑冷负荷的影响。结果表明，敏感建筑加大了热岛对建筑冷负荷的影响，热岛强度每增加1℃，敏感建筑冷负荷增加2．01％，不敏感建筑增加1．6％：而室内设计温度Tn从24℃变化到28℃时，城市热岛对建筑冷负荷的影响更加显著。     

热岛强度对办公楼空调采暖能耗的影响

城市热岛效应带来的城市温升影响着建筑物的空调和采暖能耗。利用Dest—C软件对武汉某办公楼全年冷热工况进行了模拟分析,并且得出：虽然热岛强度和空调能耗或采暖能耗影响呈线性关系,但是热岛强度对全年能耗的影响关系是呈抛物线趋势上升的。由此可以看出,办公楼全年能耗随着热岛强度的增加而以更大幅度的趋势增加。     

武汉市主城区热岛空间格局及其影响因素研究

城市空间形态对城市微气候环境的影响一直受到学界及规划管理部门的关注。以武汉市主城区589个控规管理单元为样本,运用RSGIS的技术方法识别热岛空间格局,采用多元线性回归模型揭示热岛空间分布的影响要素。研究发现:武汉主城区地表温度由中心向外围存在规律性起伏,呈现"双U"型结构;高温区团块集中、沿主干路分布,低温区在大尺度水体周边集中分布;热岛空间格局受"大江大湖"的生态格局以及大规模集中工业用地的显著影响,并与公共中心体系相关。为降低热岛效应,城市空间布局应采取相应对策。     

Hydrogen fuel cell heavy-duty trucks: Review of main research topics

Road transportation is a significant source of CO₂ emissions and energy demand. Consequently, initiatives are being promoted to decrease the sector's emissions and comply with the Paris agreement. This article synthesizes the available information about heavy-duty fuel cell trucks as their deployment needs to be considered a complementary solution to decreasing CO₂ emissions alongside battery electric vehicles. A thorough evaluation of 95 relevant documents determines that the main research topics in the past ten years converge on public policies, hydrogen supply chain, environmental impact, drivetrain technology, fuel cell, and storage tank applications. The identified research gaps relate to expanding collaboration between institutions and governments in developing joint green macro policies focused on hydrogen heavy-duty trucks, scarce research about hydrogen production energy sources, low interest in documenting hydrogen pilot projects, and minimal involvement of logistic companies, which need to plan their diesel freight's conversion as soon as possible.     

试议"凉爽城市"的建设

城市热岛效应带来一系列的负面影响对于城市正常生活的干扰日趋严重.随着生活水平的提高,人们对于夏季舒适程度的要求越来越高,而缓解城市热岛现象、创造可持续发展的"凉爽城市",需要多方面多层次的参与,因此城市管理部门的协调工作就显得至关重要.从城市、建筑、制冷设备节能等几个环节来探讨缓解热岛强度、节约能源的方法和策略,并根据这些方法、策略,从国家和地方两个层次提出创建"凉爽城市"的着手点,从而为城市管理者采取适当手段改善城市微气候提供参考和依据.     

缓解城市热岛效应的硬质景观设计方法研究综述

在城市环境中,硬质景观具有表面温度高、显热通量大的特点,对城市的小气候条件、整体的绿地品质、居民的游憩质量和热舒适度有着一定的负面影响,在一定程度上加剧了城市热岛(UHI)效应。因此,对城市硬质景观的设计优化十分重要。通过文献梳理对近年来国内外相关研究进行了系统回顾,总结了减轻UHI效应不利影响的四大硬质景观设计方法,包括空间几何形态设计、使用凉爽材料、搭配软质景观、外部机械降温。并针对以上方法的降温机制、环境适用条件、现状研究缺陷和未来发展方向进行了探讨,旨在厘清硬质景观的热效应研究进展,为城市微气候环境的改善和可持续城市景观的设计提供参考。     

减弱热岛强度的城市形态布局关键参数与响应机制

基于天津市1992-2013年7景夏季TM遥感影像,分别提取城市形态与反演城市热岛强度,利用ArcGIS与MATLAB等大数据分析计算软件,定量研究城市形态布局与热岛强度的响应机制与参数曲线,提出了热岛强度双指标测度的概念算法,即最高热岛升温和热岛升温总量.结果表明:热岛强度随着城市形态面积的增大而上升,总体上城市形态总面积与最高热岛升温、热岛升温总量都呈线性关系;城市形态离散度和临近度,与最高热岛升温不存在明显相关性,而与热岛升温总量呈线性关系;斑块面积与热岛强度呈正相关,50 km2以上的斑块,面积与最高热岛升温呈线性关系,与热岛升温总量呈二次曲线关系;周长面积比与热岛强度呈负相关,与最高热岛升温成S曲线关系,当介于[0.005,0.04]时则与最高热岛升温呈四次曲线关系;斑块分维数与热岛强度呈正相关关系,与最高热岛升温呈线性关系,与热岛升温总量呈三次曲线关系.