[关键词]
[摘要]
布哈河是青海湖最重要的径流补给河流,其流域水资源气候演变分析对于青海湖生态安全有重要意义。本文通过天骏、刚察、茶卡气象站长系列气温、降水数据分析布哈河流域气候变化特征。结果表明,近50年来,流域内气温均显著升高,海拔越高升温越明显,冬季升温较其它季节明显。采用Mann-Kendall趋势分析法和累计距平曲线对各时段的升温趋势变化进行了分析,升温自1986年开始至1997年有一个10年左右的波动期,随后在1997出现显著的突变过程,在与青藏高原整体趋势一致的基础上表现出区域自身的增温特点。降水呈增加趋势,但不如温度明显。海拔越高降水增加越明显,夏季降水增加较其它季节明显。根据气温和可利用降水变化特征,流域20世纪80年代开始进入增温增湿期,在20世纪90年代进入相对暖干期,本世纪前10年复转为暖湿期。
[Key word]
[Abstract]
Buha River is the most important recharging source for Qinghai Lake. Analysis of the evolution of climate characteristics in Buha River basin has important significance to the ecological safety of Qinghai Lake. Based on the long series of temperature and precipitation data at Tianjun, Gangcha and Chaka stations, the climate characteristics in the river basin were analyzed. The results showed that the annual mean temperature continues to rise significantly at all the three stations. At Tianjun the highest station, the annual mean temperature has increased the most. Among the four seasons, the temperature increases the most in winter. Mann-Kendall trend analysis method and cumulative anomalies were used to analyze the temperature change over the time. The temperature rise had a 10-year fluctuation period from 1986 to 1997, and then went through a significantly abrupt change in 1997. This coincides with the variation trend of temperature and precipitation on Qinghai-Tibet Plateau over the years. The annual precipitation also has increased, but not so significantly as the annual mean temperature. The increase is more significant at the higher station. Among the four seasons, the annual precipitation increases the most in summer. According to the temperature and the available precipitation, the basin is going through a continuous warm and wet period since the 1980’s. It was relatively warm and dry in the 1990’s, and then became warm and wet again in the first decade of this century.
[中图分类号]
[基金项目]
国家自然科学基金项目(51309247)