Using Californias Drought To Analyze Fractured Groundwater Inputs To High Elevation Meadows

利用加州的干旱来分析从破裂的基岩到阿尔卑斯草甸的地下水输入量化地下水的贡献对于了解干旱和未来气候变化期间的阿尔卑斯山水供应至关重要。过去对高海拔山地草甸的水文研究主要集中在积雪融化、溪流和邻近山坡上的水，以支持高山植被。考虑到加州多年的干旱，人们可以更好地识别地下基岩对高海拔草甸的地下水贡献。该项目将通过化学和同位素手段采样并更好地确定塞拉系统的深层地下水成分。该项目将与国家实验室的科学家建立联系；两名研究生将获得现场经验，学习新的现场方法，并参与实验室分析。内华达山脉国家公园和森林是对普通公众进行自然科学教育的重要户外教室。所有项目成果将提供给国家公园管理局，纳入他们的户外教育计划。这项调查将利用目前的干旱，届时来自深层裂隙基岩流动路径的贡献将产生高保真的地球化学信号，从而能够量化从基岩来源进入草地的地下水的位置和数量。该项目将演示深层基岩地下水和浅层地下水的地球化学反褶积的计算方法，这些信号可以传输到地下水输入一般未被识别的其他高海拔草甸。该项目将调查约塞米蒂地下水井中的一套自然产生的地球化学示踪剂，以确定地下水从裂隙基岩中排放到加利福尼亚州内华达山脉草甸的位置。将开发用于稀有气体和同位素示踪剂的地下水采样的新方法。通过与劳伦斯·利弗莫尔国家实验室的科学家合作，将对地下水和溪水样本进行多种化学成分分析。

Using California's Drought to Analyze Groundwater Inputs from Fractured Bedrock to Alpine MeadowsQuantifying the contribution from groundwater is critical for understanding alpine water supply during both drought and future climate change. Past hydrologic studies in high-elevation mountain meadows have focused on water derived from snowmelt, streams, and adjacent hillslopes to support alpine vegetation. Given California's multi-year drought, one can better identify previously unrecognized groundwater contributions to high-elevation meadows from underlying bedrock. This project will sample and better define the deep groundwater component of the Sierra system through chemical and isotopic means. The project will develop connections to scientists at national labs; and two graduate students will gain field experience, learn new field methods, and participate in laboratory analysis. The Sierra Nevada National Parks and Forests represent an important outdoor classroom for education of the general public in the natural sciences. All project results will be given to the National Park Service for incorporation into their outdoor education programs.This investigation will take advantage of the current drought when contributions from flowpaths in deep fractured bedrock will yield a high-fidelity geochemical signal that will enable quantification of the location and volume of groundwater entering meadows from bedrock sources. This project will demonstrate a computational methodology for geochemical deconvolution of deep bedrock groundwater and shallow groundwater geochemical signals that can be transferred to other high-elevation meadows where groundwater input has generally been unrecognized. This project will investigate a suite of naturally occurring geochemical tracers in Yosemite groundwater wells to identify the locations of groundwater discharge from fractured bedrock contributing to meadows in the Sierra Nevada Mountains of California. New methods of groundwater sampling for noble gas and isotopic tracers will be developed. Samples of groundwater and stream water will be analyzed for multiple chemical constituents through collaboration with the scientists at Lawrence Livermore National Lab.