| 摘要: |
| 近几十年，全球气候变暖日益加剧，极端气候事件频发，导致区域水文过程和能量平衡发生显著变化，对人类的生存和社会的可持续发展造成极大的威胁。青藏高原湖泊水位变化对人类活动和气候变化响应极为敏感。重建该区湖泊古水位变化，并探究其与气候变化和人类活动的关系，对妥善应对高原地区未来气候变化具有重要意义。本研究以青藏高原西部人类活动遗址边缘的夏达错为研究对象，通过对湖泊沉积物中的甘油二烷基甘油四醚（GDGTs）进行分析，基于%cren重建了夏达错地区晚全新世的古水位波动记录；结合湖芯GDGTs重建的温度记录以及粪甾醇重建的人类活动记录，探究晚全新世夏达错流域水文气候变化对人类活动的影响。结果表明：（1）4700~950 cal yr BP期间，湖泊水位整体呈上升趋势，在2750 cal yr BP、2220 cal yr BP和1000 cal yr BP左右观察到了三个较高的湖平面；950 cal yr BP左右湖水位突然降低并维持在较低水平，在大约300 cal yr BP达到最低值。（2）夏达错地区过去4700年的水文变化主要受控于印度夏季风强度变化，与降水和温度等气候条件密切相关。（3）夏达错地区湖泊水位变化对人类活动产生了较大影响，湖泊水位的急剧上升和频繁波动可能会导致流域人口数量的降低。本研究可以丰富青藏高原西部地区晚全新世气候环境变化的信息资料，为人类有效应对未来气候变化提供经验借鉴。 |
| 关键词: GDGTs 夏达错 晚全新世 古水文 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（41901105）、河南省自然科学基金项目（242300421371）、河南省高等学校青年骨干教师培养计划项目 （2023GGJS096，2020GGJS158）、河南省本科高校研究性教学改革研究与实践项目（2022SYJXLX062）和信阳师范学院“南湖学者奖励计划”青年项目联合资助。 |
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| Late Holocene paleohydrological history of Xiada Co in Nagri Prefecture of Tibetan Plateau revealed by GDGTs |
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Li Xiumei,Wang yun,Fan Baowei,Liu sutao,Wang Mingda
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Xinyang Normal University
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| Abstract: |
| Abstract: Increasing global warming and frequent occurrence of extreme weather and climate events in recent decades have led to significant changes in regional hydrological processes and energy balances, posing a great threat to the survival of human and the sustainable development of societies. Lake level changes in the Tibetan Plateau (TP) are extremely sensitive to human activities and climate change responses. Reconstructing the palaeohydrological changes of lakes in the region and exploring their relationship with climate change and human activities are of great significance for properly addressing future climate[*国家自然科学基金项目（41901105）、河南省自然科学基金项目（242300421371，222300420522）、河南省高等学校青年骨干教师培养计划项目（2023GGJS096）、河南省本科高校研究性教学改革研究与实践项目（2022SYJXLX062）、信阳师范学院“南湖学者奖励计划”青年项目联合资助。
**通信作者; E-mail: lixm@xynu.edu.cn.] change on the TP. In this study, we selected Xiada Co at the edge of human activity relic on the western Tibetan Plateau as the research subject, and we reconstructed record for paleohydrological fluctuations in the Xiada Co based on %cren by analyzing glycerol dialkyl glycerol tetraether lipids (GDGTs) in lake sediments. Combined with the temperature record reconstructed from GDGTs and human activity proxies by analyzing modern fecal stanol compounds, investigating the impacts of late Holocene hydrologic climate change on human activities in the Xiada Co. The main conclusions of this study are as follows: (1) During 4700-950 cal yr BP, Xiada Co have an overall upward trend. There were three higher lake planes observed around 2750 cal yr BP, 2220 cal yr BP, and 1000 cal yr BP. The lake level suddenly lowered around 950 cal yr BP and remained low, reaching a minimum at about 300 cal yr BP. (2) Hydrological variations over the past 4700 years in the Xiada Co has been largely controlled by changes in the intensity of the Indian summer monsoon, which are closely related to climatic conditions such as precipitation and temperature. (3) Lake level changes in the Xiada Co have had a large impact on human activities, and sharp increases and frequent fluctuations in lake levels may lead to a decrease in the number of people in the watershed. This study can enrich the information of the late Holocene climate and environmental changes in the western part of the TP, and provide experience for human beings to effectively respond to future climate change. |
| Key words: GDGTs Xiada Co Late Holocene Paleohydrology |
