Collaborative Research: Scales of Hydrologic Transients in Holocene Lake Records: Ostracodes, Groundwater Flow, and Paleochemistry

该方案解决了在全新世期间确定地下水湖泊对气候变化的水化学响应的问题。我们打算确定地下水和地表水输入麋鹿湖，格兰特公司，明尼苏达州的相对重要性。我们将检查和比较从介形类（甲壳类）物种分布、介形类外壳化学和描述水化学反应和地下水流动的模型中获得的信息。拟议的研究将提供一种独立的方法来确定湖泊在过去气候变化的特定时期如何与地下水相互作用，并深入了解湖泊-地下水系统如何对未来的气候变化作出反应。我们的方法是：1)确定目前流入麋鹿湖的地下水水源；2)从湖泊中恢复完整的全新世岩心；3)利用介形虫种类分布、微量元素和稳定同位素分析重建溶质历史；4)验证两个关于全新世地下水输入和湖泊化学的假设。该研究将为重建地表水文响应气候变化的区域变化提供新的途径，在水文气候学领域具有广泛的应用价值。这些结果对于研究地表水-地下水相互作用的水文学家，以及对气候模式验证和气候引起的水文变化预测感兴趣的气候学家应该具有实用价值。

This proposal addresses the problem of determining the hydrochemical response of a groundwater-fed lake to climate change over Holocene time. We intend to determine the relative importance of ground water and surface water input to Elk Lake, Grant Co., Minnesota. We will examine and compare information obtained from ostracode (Crustacea) species distributions, ostracode shell chemistry, and models that describe hydrochemical reactions and groundwater flow. The proposed research will provide an independent means of determining how a lake interacted with groundwater during specific times of past climate change, as well as insight into how lake-groundwater systems can react to future climate change. Our approach will be 1) define the ground water source(s) flowing into Elk Lake at present; 2) recover a complete Holocene core from the lake; 3) reconstruct the solute history using ostracode species distributions, trace-elements, and stable isotope analyses; and 4) test two hypotheses concerning the groundwater input and resultant lake chemistry through Holocene time. This study will provide a new way of reconstructing regional changes in surface hydrology as it responds to climate change and has wide application to the field of hydrology and climatology. The results should be of practical value to hydrologists concerned with surface water-groundwater interactions, and to climatologists interested in climate model validation and forecasting of climate- induced hydrologic changes.