1981—2010年台湾热不适指数之时空特征

Trend Analysis of Thermal Discomfort Index in Taiwan during 1981 and 2010

本研究分析1981—2010年间台湾地区生物气象不适指数(Discomfort Index,DI)在空间上的分布及时间上变化的趋势,结果显示不适指数的区域差异及时间上变化和趋势均相当明显。以月平均来看,台湾主要都市有将近半年的不舒适时间(DI≥24),而夏季7—8月份主要都市地区更达到极度不舒适的程度(DI≥27)。海拔>600 m的山区全年的生物气象环境皆属于舒适的范围。1981—2010年全年DI≥24及DI≥27日数的分析结果显示,30年间台湾中南部都市不舒适和极端不舒适日数皆有显著增加的趋势,北部的都市则没有明显的变化,东部地区几个都市则没有一致的结果。夏季7—8月份每日主要都市气候极端不舒适(DI≥27)的状况由8:00开始一直持续至晚上18:00,而12:00—13:00甚至接近热逆压(DI≥29)的等级,对人体健康可能造成危害。此外30年间大多数测站从夜间至清晨,不适指数皆呈现上升的趋势,使得夏季的不舒适的时间延长同时不舒适的程度加剧。气候变迁可能导致人类生物气象环境的变化,对处于热带及副热带气候交界,且有剧烈地形变化的台湾,持续观察环境舒适程度的变动,以及在数据可获得条件下再深入比较不同指数的应用性,是极具潜力而值得努力的研究方向。

We analyzed temporal and spatial patterns of thermal discomfort index（DI） in Taiwan between 1981 and 2010.The results indicated substantial variation among regions and significant temporal changes in DI.As for monthly mean DI values,all major cities in Taiwan experienced six months of thermal discomfort（DI≥24） and reached extremely discomfort（DI≥27） in midsummer（July and August） in major metropolis.In contrast,all stations with elevation higher than 600 m were in comfort condition throughout the year.The annual number of days with DI≥24 and 27 increased significantly in central and southern Taiwan.There were no significant change trends in northern Taiwan and the trends were inconsistent in eastern Taiwan.The period with hourly DI≥27,or extremely discomfort condition,in July and August began at 8：00 and last through 18：00 in major metropolis.Thermal condition reaching heat stress condition（DI ≥29） could adversely affect human health at12：00 and 13：00.There were increasing trends of hourly DI between dawn and early morning for most stations.The increasing trends lead to the extension of duration of thermal discomfort in the summer.Climate change could alter human biometeorological environment,especially for regions such as Taiwan located in the junction between tropical and subtropical climate and has dramatic topographic variation.Continuously monitoring changes in environment discomfort pattern and further exploration of the applicability of various discomfort index have high research potential and should be of high research priority.