近40a来长江流域≥10℃积温的时空变化特征

Spatial and Temporal Variation of ≥10℃ Accumulated Temperature in the Yangtze River Basin for the Past 40 Years

基于1970―2013年长江流域131个气象站点的日平均气温数据,采用气候倾向率、累积距平、M-K检验及滑动T检验等方法分析了该区≥10℃积温的时空变化特征。结果表明:1)突变时间较早的区域主要有嘉陵江流域,中游干流区,太湖流域和下游干流区(1997年);而岷江、沱江流域,鄱阳湖流域和洞庭湖流域较晚(2001年);长江源头的金沙江流域最晚(2002年)。2)在区域尺度上,1970年以来,北亚热带、中亚热带和高原气候区日平均气温≥10℃积温的初日分别以-1.25、-1.39、-0.8 d/10 a提前,终日分别以1.52、1.43、1.47 d/10 a推后,持续日数以2.97、2.92、4.62 d/10 a幅度延长。积温总体上分别以113.5、88.8、77.3℃/10 a增加。3)≥10℃积温的年际变化存在明显的空间差异,积温增加幅度较大的地区主要集中在汉中―奉节―五峰―吉首―武冈―道县以东的长江中下游地区以及四川盆地、云贵高原、青海高原的个别站点。

Accumulated temperature is an important indicator of regional thermal resources and it deeply influences the growth of crops. As one of China＇s major grain-producing areas, Yangtze River basin should be closely studied, especially on its spatial and temporal variation of the heat resources for agricultural production. Based on the data of daily average temperature collected from 131 national meteorological stations in Yangtze River basin during the period from 1970 to 2013, the spatial and temporal variation of heat resources（≥10℃） was examined by the linear trend method, cumulative anomaly method, Mann-Kendall（M-K） Test and moving T-test. The results showed that： 1） The stations with earlier time of abrupt change were mainly located in the Midstream River area, the Jialing River basin, the Downstream River area and the Taihu Lake Basin, and the time of abrupt change appeared in 1997; abrupt change in the Minjiang River basin, Tuo River basin, Poyang Lake basin and Dongting Lake basin took place in 2001, the time of abrupt change in the Jinsha River basin was in 2002. 2） The starting date of the daily average temperature（≥10℃） advanced by-1.25,-1.39,-0.8 d/10 a, the ending date of the daily average temperature（≥10℃） delayed by 1.52, 1.43, 1.47 d/10 a, the duration days of the daily average temperature（≥10℃） prolonged by 2.97, 2.92, 4.62 d/10 a, and the accumulated temperature（≥10℃） increased by 113.5, 88.8, 77.3℃/10 a in the northern subtropics zone, mid-subtropical zone and Plateau climate zone, Yangtze River Basin. 3） The annual variations of the accumulated temperature（≥10℃） were differentiated by space. The stations with wider changing range were mainly located in the east side of the line of Hanzhong-Fengjie-Wufeng-Jishou-Wugang, and several individual stations were in the Sichuan Basin, Yunnan-Guizhou Plateau and Qinghai Plateau.