湖泊是地表水循环的重要环节。青藏高原内陆湖泊众多，湖面变化是对其面积和水量变化的综合与直接反应，敏感地反映了气候与环境变化。对近40年来的湖面与气候变化研究已经取得较大进展，但对历史时期的湖面变化研究依然薄弱。末次冰消期以来气候变化经历了快速变暖的过程，青藏高原内陆湖泊也经历着西风季风相互作用的影响。阐明该时段的湖面变化及其反映的气候环境，对理解气候变化的地表过程影响非常重要。介形类组合与壳体同位素对于湖泊水深重建与湖泊补给过程分析是一类成熟的环境代用指标。本项目拟通过对西风季风影响过渡区色林错表层沉积物、钻孔沉积物中的介形类以及壳体微量元素、稳定同位素等指标进行综合分析，试图厘清色林错地区现代介形类分布特征以及与其宿生环境因子的关系；通过钻孔中介形类组合与介壳同位素指标，重建色林错的水深变化历史，并探讨其补给过程，分析该地区晚冰期以来湖面变化历史以及环境变化影响机制。

Lake is an important part of the terrestrial water cycle. There are many inland closed lakes in the Tibetan Plateau. The change of the lake level is a direct and comprehensive response to the change of its area and water quantity, which sensitively reflects the climate and environment changes. Great progress has been achieved in the study of lake level and climatic changes for recent 40 years, but the study of lake level change in historical period is still weak. Since the last glacial epoch, the climate change has experienced a rapid warming process, and the inland closed lakes of the Tibetan Plateau have also experienced the interactions between the westerly and India monsoon. It is very important, for understanding the land surface response to climatic change, to clarify the lake level changes during this period and their implied climatic environment. Ostracods assemblages and their shell isotopes have been successfully used for lake water depth reconstruction and lake supplies analysis. The proposed project will comprehensively analyze the ostracods, as well as the microelements and stable isotopes of the shell, in the lake surface sediments and borehole sediments which are taken from the Selin Co in the transition areas affected by the westerly and India monsoon. An attempt was made to clarify the distribution characteristics of modern ostracods and their relationship with their living environmental factors in the Selin Co. We will reconstruct the history of water depth variation of Selin Co by means of the combination of ostracods assemblages and their shell isotopes, and analyze the recharge process of the lake. The history of lake level change and the mechanism of environmental change since the late glacial epoch in this area have been analyzed.