近50年来石羊河流域气候变化趋势分析

采用Mann-Kendall及Meyer小波分析法,对石羊河流域乌鞘岭、武威、永昌、民勤气象站近50年来气温、降水逐月观测资料进行了分析.结果表明,石羊河流域气温总体呈上升趋势,尤其1987年以后,气温升幅显著;受全球气候变化的影响,流域中游武威、永昌地区近年来一直处于降水偏多时期,在20世纪90年代以后波动上升更为突出.石羊河流域各站点年平均气温和年降水量的变化周期基本一致,其中年平均气温普遍存在约28年、24～26年、19～20年和14年以及9～11年的中长周期以及7年左右和2～3年的短周期;而年降水量存在约28年、25年和22年的中长周期以及10年左右的较短周期,并且还存在4～6年和2～4年的短周期.

Analysis on the Climate Change in the Shiyang River Basin since Resent 50 Years

In this study,the data of monthly air temperature and precipitation,observed by the Wushaoling,Wuwei,Yongchang and Minqin meteorological stations,are used to analyze the climate change in the Shiyang River Basin since resent 50 years using Mann-Kendall method and Meyer wavelet analysis.The results are as follows:(1) Generally,the mean annual air temperature in the drainage basin is significantly increased,especially since the 1990s,which accords with the trend of global temperature increase;(2) Annual precipitation in the drainage basin is also increased in varying degrees under the background of global climate change,and it is increased all along in the Wuwei and Yongchang regions in the middle reaches of the Shiyang River Basin since recent years,especially since the 1990s;(3) The periodical change of air temperature and precipitation is basically consentaneous at all the meteorological stations in the drainage basin,there are the long-and moderate-term temperature fluctuation periods,such as the 28-year,24~26-year,19~20-year,14-year and 9~11-year periods,and the short-term ones,such as the 7-year and 2~3-year periods;there are also the long-and moderate-term precipitation fluctuation periods,such as the 28-year,25-year,22-year and 10-year periods,and the short-term ones,such as the 4~6-year and 2~3-year periods.Such periodical change is possibly related to the movement of celestial bodies,such as solar activities,and is also affected by other factors,such as land use/cover change and human activities.