不同时间尺度青藏高原湖泊水位变化影响因素分析

Analysis of the influencing factors on lake levels on different time scales on the Tibetan Plateau

使用能够指示年代际尺度及千年尺度水位变化的水位、面积和其他代用指标数据,采用经验正交分解法,研究不同时间尺度青藏高原地区湖泊水位变化规律及影响因素.结果显示:在年代际尺度上,青藏高原地区湖泊水位整体呈上升趋势,在千年尺度上,青藏高原地区湖泊水位整体呈下降趋势.不同区域湖泊水位的影响因素不同,降水和蒸发作为两大主要影响因素,在不同时间尺度上对青藏高原地区湖泊水位变化影响不同.在年代际尺度上,蒸散发在青藏高原地区湖泊水位变化影响因素中发挥主导作用,降水发挥次要作用,同时湖泊水位变化与气候、地形、风速以及温度等要素存在一定的联系;在千年尺度上,青藏高原地区湖泊水位变化主要受控于降水,其次受控于蒸散发.

A data synthesis was presented of the lake level,lake area,δ18O,total organic carbon and stalagmite,along with empirical orthogonal function to study the influencing factors on lake levels on different time scales in the Tibetan Plateau.The results showed that the lake levels exhibited an overall increasing trend on the decadal scale;on the contrary,the lake levels presented a decreasing trend on the millennial scale.These apparent differences were closely related to various driving factors on different time scales,and the evaporation and precipitation were the most important factors among them.Evaporation was recognized as a major driving force for lake levels on the decadal scale,and the precipitation played a secondary role.Lake levels were also relative to topography,climate,wind velocity and temperature shift.On the millennial scale,the changes in lake levels in the Tibetan Plateau were mainly controlled by precipitation,and then driven by evaporation.