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选取青海东部农业区的西宁、大通、互助、乐都、民和、湟源、湟中、循化、化隆、贵德和尖扎11个站及柴达木盆地的都兰、诺木洪、大柴旦、格尔木、德令哈、冷湖、天峻、小灶火、茶卡9个站,用1961～2010年逐日最低气温资料,分2、0、-2℃3个温度等级,分析50年来初、终霜冻日及无霜期的变化趋势和年代际变化特征及分布规律。结果表明,20世纪80年代以后初霜冻日逐年推迟、终霜冻日逐年提前,无霜期延长,东部农业区进入21世纪这种情况最为明显,而柴达木盆地80年代最为明显;与60年代相比,21世纪以来初霜冻日推迟,终霜冻日提前,无霜期东部农业区延长20 d,柴达木盆地延长32 d,柴达木盆地初、终霜冻历年变化比东部农业区大,无霜期较东部农业区延长明显。
Select 11 stations of Xining, Chaotian, Mutual Aid, Lidu, Minhe, Langyuan, Langzhong, Xunhua, Hualong, Youde and Jianza in the eastern agricultural area of Qinghai Province and Dulan, Nuohuhong , Dachaidan, Golmud, Delingha, Lenghu, Tianjun, small stove fire, tea card 9 stations, with the daily minimum temperature data from 1961 to 2010, points 2, 2, -2 ℃ 3 temperature class, analysis of 50 The beginning and the end of the year, the final frost date and the frost-free period and the decadal variation characteristics and distribution rules. The results show that the early frost days are postponed year by year since the 1980s, the last frost days are advanced year by year, the frost-free period is prolonged, and the eastern agricultural area is most obvious in the 21st century, while the Qaidam Basin was the most obvious in the 1980s. Compared with the 1960s , The early frost date was postponed since the 21 st century and the final frost date was advanced. In the frost-free period, the eastern agricultural area was lengthened by 20 days and the Qaidam basin was lengthened by 32 days. The changes of primary and final frost in the Qaidam basin were much larger than those in the eastern agricultural area during the frost-free period, District extended significantly.