黄河源头地区湖泊沉积物记录的全新世温度变化及水热关系

The headwater areas of Yellow River, located on the northeastern Tibetan Plateau, is one of the major water resources for west China and even large part of north China. On the background of global warming, the increased temperature and its effect on hydrological variation in rivers and lakes for the upper Yellow River has been widely carried out. However, the knowledge about the hydrological variation in rivers (runoff) and lakes, and their responses to climate change might be nit comprehensive because the instrumental records is very limited and shorter in this region. The study like this on the long time scale is very necessary. Therefore, our study is aimed to respectively quantity variation in temperature and qualitatively reconstruct river runoff changes in using clumped isotope and oxygen isotope of carbonates in sedimentary core from Lake Erling covering the Holocene on the upper reaches of Yellow River. On this base, the varied characteristic of temperature and river runoff (precipitation) should be examined to evaluate characteristic of varied temperature and river runoff, their differences, relationship and driving mechanism in warm periods like climatic optimum in the Holocene and Medieval Warm Period in the upper reaches of Yellow River. The result of this study should provide very important clue to study the evolution of precipitation or river runoff on the background of global warming, and also provide scientific reference for water resources optimal allocation on this region.

黄河源头位于青藏高原东部边缘地带，是我国西北乃至华北地区重要的水资源中心。在全球持续增温背景下，该区河流径流和湖泊水文对温度变化的响应引起研究者的广泛关注。受气象-水文站点较少和器测资料过短等因素的制约，该区河流和湖泊水文变化对气候响应的认识可能不尽全面，有必要进行更长时间尺度上深入研究。本项目选取黄河上游过水湖泊-鄂陵湖为研究区域，以该湖全新世以来的沉积物为研究对象。分析沉积物岩心中碳酸盐耦合同位素组成和氧同位素组成，分别建立黄河源头地区全新世以来的温度序列和黄河源头径流量的变化序列。通过分析黄河源头全新世以来的温度和黄河径流量（降水）特征，探讨黄河源头地区全新世大暖期和中世纪暖期温度和黄河径流量的变化特征、差异、相互关系和驱动机制，有望为全球变暖条件下该区降水或黄河径流量演化研究提供重要的、关键性证据，同时为该区可持续发展要求的水资源配置规划提供科学依据。

国家自然科学基金面上项目“黄河源头地区湖泊沉积物记录的全新世温度变化及水热关系”（批准号：41672163）以黄河上游过水湖泊-鄂陵湖为研究区域，以该湖全新世以来的沉积物为研究对象，分析沉积物岩心中碳酸盐团簇同位素组成和氧同位素组成，分别建立黄河源头地区全新世以来的温度序列和黄河源头径流量的变化序列。通过分析黄河源头全新世以来的温度和黄河径流量（降水）特征，探讨黄源头地区全新世大暖期和中世纪暖期温度和黄河径流量的变化特征、差异、相互关系和驱动机制，为全球变暖条件下该区降水或黄河径流量演化研究提供重要的关键性证据。项目开展以来，我们紧密围绕这些目标开展工作，2017年在扎陵湖和鄂陵湖以及周边湖泊开展了岩心获取工作，并开展了湖泊原位观测和沉积物捕获器的布置，针对获取的样品开展了年代学测定和相关地球化学指标的测试工作。初步获得了扎陵湖和鄂陵湖沉积物岩心的年代学框架以及基于GDGTs的温度变化序列。同时我们还初步获得了青藏高原湖泊介形类及细粒碳酸盐的Δ47数据，对湖泊碳酸盐团簇同位素用于古温度定量重建进行了初步验证，限于测试方法的局限，目前还没有测定钻孔岩心的Δ47。在该基金资助下已经发表SCI论文6篇，其中项目负责人均为第一作者或通讯作者。