最近几十年的全球升温和城市化导致了城市地区热环境的持续恶化。由于建筑物密集、绿化少、人口多等原因，城中村的热环境恶化现象更为明显。近年来对城中村的热环境问题的研究，以定性讨论的多，定量的研究少，其主要原因是缺乏系统的观测数据。以地处亚热带的特大城市深圳市为例，选取平山村及绿地为研究对象，通过一年的运动样带观测，分析对比了晴天和极端高温条件下城中村和绿地的热环境特征、热岛强度和热环境舒适度，探讨了影响城中村热环境的主要因素。结果表明：深圳城中村热岛效应明显，月份间的热岛强度关系为：降雨量少的月份热岛更强；一天中各时段的热岛强度变化特征为：热岛强度在日落之后逐渐加强，在20：00至24：00间达到最大值，在午夜后逐渐减弱，最强热岛强度出现于2月份的20：00时，达3.95℃。5月至9月深圳的热环境特征为炎热潮湿，热环境极不舒适，城中村与绿地夜间温湿指数差异明显，城中村较绿地热环境不舒适性增加一个等级，夜间为城中村居民室外活动最为频繁的时候，因而对城中村居民带来不舒适的直接感受，进入后半夜之后会进而影响居民的休息，增加空调等的使用，高极端高温天气条件下，城中村与绿地的热环境较普通夏季平均值更为不舒适，容易引发中暑等危害。城中村人工下垫面较自然下垫面占比大，改变原有的水热平衡且引入更多的人为热排放，是引起热岛效应及热环境不舒适的主要原因。这些研究结果可以为城市规划设计提供理论依据。%Climate change and urbanization lead to worse thermal environment in urban area. Urban village is an endemism in China, with dense buildings and few vegetation, resulting in terrible thermal environment. The research focuses on Pingshan Village of Shenzhen, a typical urban village in Pearl River Delta Region. According to air temperature and relative humidity data obtained by mobile traverses from November 2011 to October 2012, the research analyzed the characteristic of urban heat island intensities in fine weather days, extreme hot days, together with thermal comfort index of urban village comparing to those of green space. Shenzhen was affected by tropical monsoon climate of South Asia, with summertime lasting for half a year, with highest air temperature of 30℃ and highest relative humidity of 90%. The results showed that urban heat island intensities during dry months were stronger than those of wet months. Urban heat island intensity of urban village usually increased after sunset and decreased after midnight, with highest value occurred in the time between 20:00 and 24:00, reaching 3.95℃ at 20:00 of February. Shenzhen experiences summertime from May to September, with hot and humid weather. During this period of time, the Average urban heat island intensity was 1.71℃ from 18:00 to 24:00, when residents returned to urban village, making an uncomfortable environment for them. Moreover, the research calculated thermal humidity index (THI) to figure out the differences of thermal environment situation between urban village and green space. The thermal environment was terrible during June to August of both areas, while THI of urban village was higher than reference green space, meaning worse thermal environment, especially during nighttime. The thermal environment got worse during extremely hot days in urban village, leading to higher urban heat island intensities and higher THI, resulting in more terrible thermal environment. The terrible thermal environment of urban village was ascribed to changing of underlying surface from natural land to artificial land, leading to changes of heat balance and water balance.
展开▼
