【作者】 王琪；

【导师】 赵敬源；

【作者基本信息】 长安大学 ， 建筑技术科学， 2010， 硕士

【摘要】 城市绿化是城市建设的一个重要组成部分。作为改善城市热环境最经济、最有效的手段之一,绿化对室外热环境的作用,表现在改善区域微气候、缓解城市热岛效应、平衡城市生态系统和提高城市居民生活环境质量等多个方面。本文分析了绿化对室外热环境影响研究领域的现状,总结了目前在研究方法及应用领域存在的不足,并针对这些问题,以夏季西安地区常见城市绿化乔木为例,开展了以下研究：第一,分析了绿化影响热环境的作用机理和作用方式,从热环境作用的角度对植株进行了分类,特别分析了计算机模拟无法显示的不同植株生物物性因素在不同气候条件下对城市热环境的影响方式,将目前城市常用绿化树种的不同物性组合分成五种典型形态,为绿化设计植株的选择提供了依据。第二,以西安市为例,优选了不同形态的代表树种,并对所选研究对象进行各项物理特性参数的实际测量,得到了不同乔木的热环境指标数据和变化规律曲线图,分析了不同物理特性的乔木对室外热环境的影响程度。并选择湿黑球温度WBGT作为评价室外热环境舒适度指标,对不同乔木进行热舒适评价。实验表明乔木对改善微气候的作用优于草坪,其中得到高杆乔木周围风速大于低杆乔木,LAI值大的乔木对温度影响程度大于LAI值小的乔木,倒圆锥形树冠对热环境改良的影响面积较其他冠形略大的结论。第三,分析了计算机模拟同实验研究之间的相关性,通过实验验证了计算机模拟的理论趋势,分析了计算机模拟的缺陷所在,从目前实测结果和模拟结果的对比分析来看,从宏观角度,比如绿化形式的比较、绿量的比较等方面,两者的研究结论基本上是一致的；但从生物性方面,比如城市绿化树形的比较、树冠的比较等方面,模拟研究还无法深入,仍应以实测研究的结论作为参考依据。本论文利用实测的方法研究了城市绿化对城市热环境的影响方式和影响程度,从数据出发归纳出植被对环境的作用规律,为科学合理地优化城市绿化设计改善户外环境提供了理论基础。更多还原

【Abstract】 Urban greening is an important part of urban construction. Greening, as one of the most economical and effective means to improve urban thermal environment, can take effect on urban thermal environment in improving regional micro-climate, easing the urban heat island effect, balancing urban ecosystem and improving the urban living environment and so on. This article analyzed the status of the impact of greening on outdoor thermal environment and summarized the disadvantages of the research methods and applications, To solve these problems, the report, taking the Xi’an city green tree in summer as an example, studied and carried out:Firstly, the paper analyzed the theory and mode about the influences of the green on thermal environment, classified the plants from the perspective of the thermal environment, and especially analyzed of effects on the urban thermal environment on different plant biological factors in the different climatic conditions which the computer simulation can’t display. In this research, the common city trees could be divided into five typical patterns, which may provide the basis of options for the green design.Secondly, taking Xi’an City as a case, the study selected optimized representative species in different forms, measured physical parameters of selected subjects in practice, and obtained thermal environmental indicators data and change curve of different trees, analyzed the influence of outdoor thermal environment by the different physical characteristics of trees. The study selected the wet globe temperature WBGT as the evaluation index of outdoor thermal comfort and evaluated thermal comfort of different trees. The experiments showed that the trees improve micro-climate better than the grasses; the wind speed around the tall trees is higher than it with the low trees; the trees of large LAI affect the temperature greater than the trees with small LAI, reversed pyramid-type crown improves more areas for thermal environment than other bigger crowns.Thirdly, the study analyzed the correlation between computer simulation and experimental research. Experimental results showed the theoretical trends in the computer simulation and shortcomings of computer simulation. Compared with experimental and simulation results, both got a basically same conclusion, from a macro point of view, such as comparison of greening forms, green biomass and so on; The simulation can’t study in-depth, from the biological viewpoint, such as comparison of urban green trees and crown, so it should take experimental results of the study as a reference.This thesis studied the forms and extent of effects on urban thermal environment by the urban greening by measurement, summarized the pattern of the trees impacting on thermal environment from the data, and provided a theoretical basis for improving urban green design and outdoor environment scientifically and rationally.更多还原