Collaborative Research: Testing Potential of Paired Lakes on the NE Tibetan Plateau for Studying Interaction Between Hydrochemical Evolution and Environmental Change

合作研究：测试青藏高原东北部成对湖泊研究水化学演化与环境变化之间相互作用的潜力

• 批准号: 0518774
• 负责人: Zicheng Yu
• 金额: $ 4.88万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0518774&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Potential; Paired

The evolution of the chemical composition of lake waters is determined by the inflow waters andsubsequent evaporative concentration and the precipitation of minerals. In closed-basin lakes, evaporativeconcentration is mostly determined by changes in aridity, as a result of regional climate change. However,the interactions among lake water and groundwater chemistries, lake sediment geochemistry, andenvironmental change have not been studied over short or long time scales, and seldom usingmultidisciplinary approach.Intellectual merits. This pilot study is to investigate paired chemically-contrasting lakes (fresh andsaline) in the arid northeastern Tibetan Plateau. These lakes are likely to be ideal sites for the study ofwater isotopic and elemental evolution, and the interactions of environmental change and lacustrinegeochemical processes. The overarching objective of the proposed study is to understand hydrochemicalevolution and how it interacts with various environmental controls at different time scales. The addedbonus for undertaking such a study in this climate-sensitive region near the northern limit of the EastAsian monsoon is to improve our ability to read the lacustrine sediment record of this region to betterunderstand the past environmental changes. We propose to use a multidisciplinary approach to investigateat regional and watershed scales, the modern processes in these two lakes, history of solute and water fluxfrom mineralogy and chemical and isotopic composition of authigenic and biogenic minerals, and fromspecies assemblage of ostracodes and the history of climate and environmental change from such recordsof landscape processes as pollen, plant macrofossils, and environmental magnetism.The results from this project will provide insights into understanding the pathways and mechanisms oflake solute evolution and water flux and how they affect the sedimentary record of past environmentalchanges. This is the first study to employ a multidisciplinary approach to address the lake-climateinteractions in Central Asia. A key feature of this project is in its use of paired limnologically- andchemically-contrasting lakes in order to unravel the interactions between lacustrine hydrologic andhydrochemical processes and environmental (and climatic) changes. The study of modern responses ofthe dilute lake (Keluke Lake) with a saline Lake (Toson Lake) will enable comprehensive and robustreconstructions of paleohydrochemistry. Also, the multiple techniques used in the proposed study willprovide independent records of regional climate change, watershed stability and vegetation, as well aschanges in lake chemistry. Integration of these records will allow us to focus on the complex interactionsand feedbacks between these processes at different temporal scales (from present-day to interglacialglacialcycles).Broader impacts. Our interdisciplinary research will advance the understanding of complex interactionsin these systems under different climate regimes. Understanding the lake and watershed responses toclimate change of the past will contribute to our ability to predict the environmental consequences ofclimate (especially monsoon) variations and variability. Our approach of using contrastinghydrochemistries of paired fresh and saline lakes is not commonly employed but we believe is a veryinstructive one with a large pay-off. Understanding the hydrological dynamics will benefit the people inthis remote arid part of China in adapting to the potential future changes in climate and hydrologicalcycles. The results will be compared with the response of lakes in the semi-arid northern Great Plains toclimate and hydrololgic changes and shared with the state geological surveys and water commissions.Once past the pilot-stage, graduate and undergraduate students will be more fully involved in the projectand will benefit from interacting with an international multidisciplinary research team. The project willfacilitate collaborations, especially with our Chinese colleagues, who are having increased impacts in theinternational scene of science and technology.

湖泊沃茨化学成分的演变是由流入的沃茨和随后的蒸发浓缩和矿物沉淀决定的。在封闭流域湖泊中，蒸发浓度主要取决于干旱的变化，这是区域气候变化的结果。然而，湖泊水和地下水化学、湖泊沉积物地球化学以及湖泊环境变化之间的相互作用还没有在短时间或长时间尺度上进行研究，也很少采用多学科的方法。本研究对青藏高原东北部干旱区的淡水和咸水成对湖泊进行了初步研究。这些湖泊可能是研究水体同位素和元素演化以及环境变化与湖泊地球化学过程相互作用的理想场所。拟议研究的首要目标是了解水化学演变以及它如何在不同的时间尺度上与各种环境控制相互作用。在这个靠近东亚季风北方界限的气候敏感地区进行这样一项研究的额外好处是提高我们阅读该地区湖泊沉积物记录的能力，以更好地了解过去的环境变化。我们建议采用多学科的方法，从区域和流域尺度上研究这两个湖泊的现代过程，溶质和水通量的历史，从矿物学和自生矿物和生物矿物的化学和同位素组成，从介形类的物种组合，以及从花粉，植物宏体化石，该项目的研究结果将有助于理解湖泊溶质演化和水通量的途径和机制，以及它们如何影响过去环境变化的沉积记录。这是第一项采用多学科方法来解决中亚湖泊-气候相互作用的研究。该项目的一个主要特点是使用成对的湖沼和化学对比湖泊，以揭示湖泊水文和水化学过程与环境（和气候）变化之间的相互作用。研究稀释湖（克鲁克湖）对盐湖（托克逊湖）的现代响应，将有助于全面而有力地恢复古水化学。此外，在拟议的研究中使用的多种技术将提供区域气候变化，流域稳定性和植被，以及湖泊化学变化的独立记录。这些记录的整合将使我们能够专注于这些过程在不同时间尺度上（从现在到间冰期冰川周期）之间的复杂相互作用和反馈。我们的跨学科研究将推进对这些系统在不同气候条件下复杂相互作用的理解。了解湖泊和流域对过去气候变化的响应将有助于我们预测气候（特别是季风）变化和变率的环境后果。我们使用淡水湖和咸水湖的对比水化学的方法并不常用，但我们相信这是一个非常有指导意义的方法，有很大的回报。了解水文动力学将有利于中国偏远干旱地区的人们适应未来气候和水文循环的潜在变化。研究结果将与半干旱北方大平原湖泊对气候和水文变化的响应进行比较，并与国家地质调查局和水利委员会分享。一旦通过试点阶段，研究生和本科生将更全面地参与该项目，并将从与国际多学科研究团队的互动中受益。该项目将促进合作，特别是与我们的中国同事的合作，他们在国际科学和技术领域的影响越来越大。