城市居住区三维绿色空间影响空气温湿度的机制研究

以郑州市居住区为例,采用手持式路昌LM-8000四合一环境测量仪,对郑州市区中不同方位、不同高度、不同布局形式分类的6个居住区微气候环境进行观测,对气温、相对湿度等气象数据进行分析,并探讨绿色空间布局形式影响空气温湿度的机制。结果表明：居住区白天相对湿度的变化幅度高于温度;测量日内,高层小区和多层小区的温湿度达到最大值的时间不同;在静风条件下,植物蒸散和阴影影响的范围为10~50 m,相对湿度的影响范围为10~50 m;居住区相对湿度最小值、均值分别与测点10 m范围内绿色空间的分形维数有关;相对湿度最大值与50 m范围内绿色空间的形状指数有关;白天时段,湿度的变化与50 m范围内的形状指数和连接度指数有关。     

西江中下游生态公益林小气候特征

对广东省德庆县三叉顶自然保护区的生态公益林气温、相对湿度和太阳辐射进行了定位观测,以空旷地为对照,分析生态公益林的小气候效应.结果表明:在2006年8月和2007年5月典型晴天,生态公益林林地气温平均比空旷地气温分别低1.7和1.6℃,林地相对湿度平均比空旷地相对湿度分别高8.3%和2.2%,2006年8月和2007年5月典型晴天森林平均透射率分别为5.9%和7.7%;空旷地与林内的气温、相对湿度和太阳辐射相关性极显著,相关系数分别为0.979、0.879和0.889.     

Temperature and water-use efficiency by lucerne (Medicago sativa) sheltered by a tree windbreak in Tunisia

Based on the assumption that with unrestricted water availability, temperature will determine the response of sheltered crops, the effects of a Casuarina glauca Sieb. windbreak on the microclimate, water use and biological production of a lucerne crop were investigated. Degree-days (dd) were used to compute an index for the efficiency of the thermal effects of the shelter on a well- watered lucerne, under favourable (10 to 30 °C) and unfavourable (above 30 °C) temperature conditions. Water use efficiency was considered for two contrasting water regimes, with no water stress or with a large water deficit. In June, under favourable temperature and water availability conditions, temperature efficiency of the windbreak was 39 g m−2 dd−1 at a distance of three times the height of the trees compared to an exposed situation, and water use efficiency increased by 7.1 g mm−1. However, the sheltered conditions induced a decrease in above ground biomass production and water use efficiency when a highly restrictive water regime was applied. In July, daytime temperatures were disadvantageous to the lucerne, and even with a high degree of water availability, there were no significant differences between sheltered and unsheltered conditions. This research may help decision makers to manage windbreak systems by designing an appropriate irrigated area according to the shelter and choosing crops that will best benefit from sheltered conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Thermal Comfort Maps to estimate the impact of urban greening on the outdoor human comfort

Outdoor human comfort is an important factor in the evaluation of the liveability of a city as well as for promoting people’s health and well-being. In hot arid climates in particular, urban planning and design can considerably impact the day-to-day thermal comfort of the pedestrians, for better or for worse. Strategies to reduce thermal discomfort include shading structures, water bodies, and the promotion of natural ventilation – and most significantly, green areas. Trees have a major impact on the pedestrians in the built environment as they not only provide shading but also improve the microclimate in urban areas, thereby reducing the time during which discomfort is felt. The objective of this paper is to present a new methodology for dynamically quantifying the impact of different plants in urban areas on outdoor human comfort, through 3D urban energy modelling. The proposed methodology makes use of an urban energy modelling tool, providing a comprehensive view of the city energy fluxes, with a focus on the impact of trees on the human thermal comfort. Outdoor human comfort is assessed using the Index of Thermal Stress for the campus of the Swiss International Scientific School of Dubai (UAE), where “Thermal Comfort Maps” are designed to quantify the pedestrian thermal sensation and its variation in time and space. Additionally, the energy fluxes impinging on the urban pedestrians are quantified, dynamically, in hourly time step, providing an important instrument to understand their thermal stress, and the environmental factors affecting it. Based on the simulations, thanks to native greening, a significant improvement in outdoor comfort conditions was achieved in the campus, reducing the “warm/hot” and “very hot” thermal sensations from 1,291 h (on average over the entire campus) to less than 300 h by planting Ghaf and Acacia trees.     

南方地区新型羊舍环境评价及对山羊日增重的影响

为了研究新型羊舍夏季小气候环境以及设计合理的饲养密度，在夏季检测了新型羊舍和西南地区常见的双坡顶漏缝地板有窗封闭式羊舍的空气环境参数，同时测定了不同饲养密度羊舍对羊体增重的影响。结果表明：①新型羊舍日平均温度和日最高温度极显著低于有窗封闭羊舍（P＜0.01）；有窗封闭羊舍与新型羊舍相比，相对湿度显著较高（P＜0.05），同时羊舍内湿度极显著高于外界湿度（P＜0.01）；②通过称重比较，试验期间低密度组羊只的体增重极显著高于中密度组和高密度组，当饲养密度增加一倍时，羊只的体增重极显著降低（P＜0.01）。综合分析认为，新型羊舍夏季小气候环境明显优于有窗封闭羊舍；在合适的饲养密度下，羊舍羊群增重效果好，羊群发病率低。     

福州高架桥下植物景观空间微气候舒适度评价

文章采用不同舒适性指标探究植物景观对福州高架桥下空间微气候舒适度的影响,结果表明,代表舒适性指标的典型变量V1主要受S指标(综合舒适度指数)的影响;代表微气候因子的典型变量W1主要受空气温度、环境平均辐射温度、相对湿度的影响;太阳辐射强度、空气温度、环境平均辐射温度与舒适性指标呈正相关,相对湿度、风速与舒适性指标呈负相关;S指标是较好的舒适性指标;乔灌草是桥下空间最佳的植物景观类型,降温幅度在1℃~2℃。该结果可为福州市高架桥桥下植物景观空间的热舒适环境提供评判依据。     

新型连栋日光能温室小气候初探

【目的】研究新型连栋日光能温室室内小气候的分布特点,分析其在长江流域的实用性和可行性,为长江流域地区温室的结构设计和生产管理提供理论依据。【方法】分别于夏季(2017年6―7月)和冬季(2017年1月和12月以及2018年1月),在新型连栋日光能温室的前跨、后跨、室外设置不同传感器,测定了温室室内和室外气温、相对湿度、辐照度、曝辐量和薄膜热通量等,分析温室气温、相对湿度、气候因子均匀度变化和冬季温室内光照分布的特点。【结果】夏季温室前跨气温日平均值、日最高值与日较差分别为26.84,32.77和9.64℃,比后跨分别高0.53,1.41和1.30℃,但二者以上指标间均无显著差异;后跨相对湿度的日平均值、日最低值及日较差分别为88.05%,69.89%和29.48%,日平均值和日最低值显著高于前跨,而日较差显著低于前跨。冬季前跨日最高气温为22.98℃,较后跨提高了2.35℃;后跨日最低气温为7.18℃,分别比室外和前跨增加了8.26和2.95℃。光照分布上,晴天和阴天前跨的采光时长均显著高于后跨。晴天前跨与后跨日平均辐照度和平均日曝辐量无显著差异,而阴天前跨的日平均辐照度与平均日曝辐量显著高于后跨。晴天和阴天温室前跨日平均透光率均高于后跨。日间温室前跨向后跨传热约56 MJ,夜间后跨向前跨传热约43.27 MJ。【结论】探明了连栋日光能温室小气候变化规律,为其在长江流域地区的周年生产提供了参考。     

午潮山常绿阔叶林小气侯特征的初步研究

应用杭州午潮山１９８８～１９９０年的气象观测资料，阐述杭州午潮山常绿阔叶林林内、林外的小气候特征以及小气候差异。     

冬季温控床垫对人体热舒适的影响机理

为研究温控床垫的不同温控条件对人体冬季热舒适和睡眠质量的影响,以及获得适宜的被褥微环境温度,研制了基于水管和水垫调温的温控床垫,调控的温度分别为29和32℃。通过睡眠实验,测试并记录睡眠过程中人 床界面温度、被褥微环境温度与睡眠各个阶段时间,以及睡前和醒后的主观热反应调查。结果表明,在受试者睡眠期间,受温控条件水垫29℃影响的人 床界面与被褥微环境的温度值最低,热感觉处于稍凉水平,导致睡眠效率较低。水管29℃热感觉处于适中水平,水垫32℃与水管32℃处于稍暖水平,二者之间受试者热感觉差异不显著,而与水垫29℃差异显著。同时,适中或偏暖被褥微环境在人体热舒适和热可接受度方面表现最佳,也实现了较高的睡眠效率。基于睡眠效率、被褥微环境的温度及整体热感觉,得出适宜的被褥微环境温度范围为31.45~32.50℃,受试者的满意率可达85%以上。此外,睡眠时被褥微环境的整体热感觉与各睡眠参数之间显著相关,稍暖或稍凉的热感觉会显著影响人的睡眠质量。     

Heat damage in tree seedlings and its prevention

Tree seedlings start to suffer stem damage or tissue death when the temperature at the soil surface reaches approximately 52°C. Seedling mortality rate accelerates as temperatures increase. Resistance to heat damage increases with size as the ability of a seedling to shade its base increase. Small newly germinated seedlings are at risk in late spring and early summer, while larger nursery-grown seedlings are at risk in mid to late summer, especially on soils with low heat capacity or conductivity, or with surfaces that are dry, dark colored or covered with organic matter. Heat damage to natural and planted seedlings usually occurs on flat or south-facing sites in regions with hot dry summers and clear skies, but can also occur in wetter regions under dry clear conditions. Shading only the basal portion of the stem appears to be as effective in preventing heat damage as shadingthe entire stem and some foliage, which can also reduce transpiration. Overhead shade and shade from live plants can reduce growth and survival.