青海湖水位波动对气候暖湿化情景的响应及其机理研究

利用1961—2015年青海湖水位资料及其流域气温、降水量、蒸发量等气象观测资料,高原季风、西风环流气候等指数及植被数据,分析青海湖水位波动的基本特征,揭示高原季风、西风环流、植被覆盖、径流以及冻土退化对湖泊水位波动的影响机理,建立基于水量平衡的青海湖水位变化的定量评估模型。研究表明：2004年前后,青海湖水位出现由降到升的突变,自2005年以来持续回升;水位波动具有8 a和21 a的显著性周期;全球变暖背景下高原季风增强、西风环流趋弱、气候趋于暖湿、流域植被恢复、冻土退化和径流量显著增大,引起了2005年以来青海湖水位的持续回升。基于湖泊水量平衡原理建立的气候变化对青海湖水位影响定量评估模型,能够客观反映青海湖流域上年及当年降水量、流量和蒸发量对湖泊水位的效应。

Response of water level fluctuation to climate warming and wetting scenarios and its mechanism on Qinghai Lake

In the context of water level data of Qinghai Lake, meteorological observational data including temperature, precipitation and evaporation in its basin and climate indexes such as plateau monsoon and westerly circulation from 1961 to 2015, the characteristics of water level fluctuation of Qinghai Lake were analyzed, influence mechanism of plateau monsoon, westerly circulation, vegetation cover, runoff and permafrost degradation on water level fluctuation of lake level were revealed, the quantitative evaluation model on water level changes of Qinghai Lake were established. The water level in Qinghai Lake showed a mutation from descending to rising in 2004 and a continuous rising for 11 years after 2005. The fluctuation of water level had 8 years and 21 years significant periods. Plateau monsoon enhancement and westerly circulation weakening, climate warming and wetting, vegetation restoration, permafrost degradation and runoff increasing, all brought about water level rising continuously after 2005. Quantitative evaluation model based on water balance principle can reflect the influential effect on water level fluctuation caused by precipitation, runoff and evaporation in the previous and current year objectively.