近40年青海浅层地温的变化特征

Variation Characteristics of Shallow Soil Temperature in Qinghai Province in Last 40 Years

利用1971-2010年青海25个观测站5-20cm土层的逐月平均地温资料,采用气候统计诊断分析方法,对近40a青海年、季平均地温的气候变化趋势及突变特点进行研究。结果表明,近40a青海5-20cm土层年平均地温呈上升趋势,大柴旦升温幅度最大,为0.79℃/10a(P<0.01)。5、10、15、20cm 4个土层年平均地温均呈上升趋势,升幅最大值为0.77～0.82℃/10a(P<0.01),均以大柴旦升温幅度最大,10cm土层自1981年以来增温尤为明显。近40a四季平均浅层地温均呈上升趋势,增幅为0.30～0.53℃/10a(P<0.05),以夏季增幅最大,冬季最小。1971-2010年大部站点各层在1997年发生了气候突变,浅层地温与地表温度和气温均呈明显的正相关,气温、地表温度的显著升高在很大程度上解释了浅层地温呈明显升高趋势的原因。研究结果对合理利用气候资源,调整农作物种植结构并合理安排农业生产布局具有参考价值。

The annual and seasonal climate change tendency and climate abrupt change of average soil temperature in latest 40 years were analyzed, by using climate statistical diagnosis analysis method, based on the monthly average soil temperature data of 5 -20cm from 25 observation stations in Qinghai that the annual average soil temperature of 5 -20cm increased in last province from 1971 to 2010. The results showed 40 years, the max increasing found in Dachaidan region at the rate of 0. 79℃/10y （P 〈 0.01 ）. The annual average soil temperature in levels of 5cm, 10cm, 15cm ,20cm also showed rising trend,which ranged from 0. 77℃/10y to 0. 82℃/10y（ P 〈0. 01 ）. The max increasing also found in Dachaidan, and the trend was obviously from 1981 in 10cm soil level. The average seasonal shallow soil temperature in last 40 years increased at the rate of 0.30＇-0.53℃/10y（ P 〈0. 05） ,the max increasing found in summer and the min increasing found in winter. Climate abrupt change occurred in 1997 for most stations, and there was a clear positive correlation between shallow soil temperature, surface temperature and air temperature. The air temperature and surface temperature rising might resulted in the ahallow soil temperature increasing. The results could provide references to optimal utilize climate resources and to adjust agricultural structure.