夏热冬冷气候城市公共空间热环境季节特征

Seasonal Characteristics of Thermal Environment in Urban Public Space of the Urban in Hot-summer and Cold-winter Region

城市公共空间热环境是影响人们热舒适程度的重要因素。夏热冬冷气候城市公共空间的热环境在一年内会发生很大变化。在长沙市内选择3个典型公共空间(街道、公园和广场)进行长期热环境参数实测实验。通过对不同季节3个实测点的空气温度、相对湿度、黑球温度和风速4个重要热环境参数进行分析,获得夏热冬冷气候城市公共空间的全年热环境特征。研究结果表明:自然气候决定了城市热环境的基本特征,而城市物理结构是引起室外局部热环境发生改变的重要因素;受植物(乔木)和水体(湘江)的影响,沿江街道在全年大部分时间中空气温度显著较低,相对湿度较高,太阳辐射较弱;广场温度较高,太阳辐射较强。

Thermal environment in urban public space is considered as an important factor affecting thermal comfort of human beings. In the whole year, thermal environment in public space of the city in hot-summer and cold-winter zone changes dramatically, which has an effect on human thermal comfort. In this study, three typical public spaces including street, park and square of Changsha were selected for a long-term experiment of thermal environment. Based on the analysis of four significant thermal environment parameters-air temperature, relative humidity, global temperature and wind speed, seasonal characteristics of thermal environment in urban public space were obtained. The results show that the characteristics of urban thermal environment are determined by natural climate, while the physical structure of a city has essential impact on the changes of local outdoor thermal environment. Affected by plants （trees） and water （Xiangjiang river） air temperature of the street along the street is much lower, relative humidity is higher and solar radiation is weaker in most of the year. Compared to the street along the river, air temperature of the square is higher and solar radiation is stronger.