1958—2017年太湖流域气温及降水变化研究

太湖流域位于我国长江中下游平原河网地区,是受全球气候变化和人类活动影响最显著的地区之一。该文利用太湖流域范围内的21个气象站点的长期观测资料,运用趋势系数、气候倾向率等方法分析了该区域的气候时空变化规律。结果表明,1958—2017年该区气温有显著上升趋势,平均气温以0.293℃/10a幅度升高。各月气温均呈上升趋势,但是冬、春季升温最为剧烈,达0.362℃/10a;夏、秋季最弱,为0.222℃/10a。由于最冷月平均温度升高比最热月大,所以导致气温年较差减少。气温升高存在显著的区域差异,东部地区增温剧烈,气温倾向率大于0.4℃/10a;最小的气温倾向率位于西南部地区,小于0.25℃/10a。流域降水总体呈增加趋势,平均年降水量倾向率为3.026mm/10a,东部地区和无锡、常州地区降水增加显著。全球变化及城市化的影响是导致流域气温和降水地区差异的主要原因。

Study on the change of air temperature and rainfall in the last 60 years in the Taihu watershed

In the past 60 years,Taihu watershed has tremendously gone through global climate and human activities.Based on the monthly data of air temperature and rainfall in these years from 21 meteorological stations in the Taihu watershed,the climatic variations and tendencies were analyzed by calculating climate trend coefficient and climate tendency ratio.The result showed that from 1958 to 2017,there was an increase of 0.293℃/10 a in the annual mean air temperature.Monthly air temperatures were all tending to rise while increase of air temperature in the winter and spring is higher(0.14℃/10 a)than those in summer and autumn.Rise of air temperature in the cold season was higher than that in hot season,so the yearly range of the air temperature was tending to decrease.The rise in temperature was regionally different.East area had the higher rising degree(>0.4℃/10 a)while the west and south margin areas had the lowest rising degree(<0.25℃/10 a).Tendency of rainfall was increasing and the tendency ratio was 3.026 mm/10 a,most obvious in eastern areas,Wuxi and Changzhou.Global changes and the impact of urbanization were the main reasons for regional differences in air temperature and rainfall.