城市化对宁波地区极端气温及人体舒适度的影响

利用浙江省沿海宁波市鄞州站(城区)和石浦站(海岛)1956—2018年逐日最高气温、最低气温、相对湿度和风速资料,结合宁波1978—2017年城市化进程参数,研究城市化进程对人体舒适度气象指数(BCMI)及相关气象要素的影响。结果表明:(1)宁波沿海城市城区和海岛年平均最高气温、最低气温均呈增高趋势,城市化进程对城区最高气温、最低气温增幅的贡献率分别为32.3%、48.8%;(2)城市化导致城区年平均相对湿度呈减小趋势,海岛站相对湿度变化不明显;(3)城区和海岛年平均风速均呈减小趋势,城区风速突变年份相对更早,但风速的减小主要是气候自然变化所致,与城市化进程关系不大;(4)气温对人体舒适度指数BCMI的影响最大,城区夏季和冬季极端气温下的BCMI均表现出增大趋势,夏季往炎热不舒适方向发展,冬季则往舒适方向发展;(5)宁波城市化进程参数K与城区BCMI表现出明显的正相关性,城市化进程对城区夏季最高气温和冬季最低气温增幅的贡献率分别为57.8%和46.1%。

Impact of Urbanization on Extreme Temperature and Human Comfort Degree in Ningbo City

Based on the daily data of maximum and minimum temperatures,relative humidity and wind speed at Yinzhou station(urban area)and Shipu station(island)of Ningbo in coastal areas of Zhejiang Province during 1956-2018,combined with the urbanization process parameters of Ningbo during 1978-2017,the body comfort meteorology index(BCMI)and related meteorological factors during the urbanization process were studied.The results are as follows:(1)The annual mean maximum and minimum temperatures of urban areas and islands in Ningbo coast both exhibited increasing trend,and the contribution rates of urbanization to the increase of maximum and minimum temperatures in urban areas were 32.3%and 48.8%,respectively.(2)Urbanization resulted in decreasing trend of annual mean relative humidity in urban areas,while relative humidity of island stations didn’t change obviously.(3)The annual mean wind speed of the urban areas and islands had a decrease trend,while the abrupt changing year appeared earlier in the urban areas.The natural climate change mostly resulted in decrease of wind speed in urban areas.(4)Temperature had the greatest impact on BCMI.The BCMI under extreme temperatures in summer and winter in urban areas exhibited an increasing trend.It was going hot and uncomfortable in summer while moving toward comfort in winter.(5)The urbanization process parameter(K)of Ningbo was significantly and positively correlated with BCMI in the urban areas.The contribution rates of urbanization to increase of maximum temperature in summer and minimum temperature in winter were 57.8%and 46.1%,respectively.