Doctoral Dissertation Research: Understanding Intermittent Water Sources and Impacts on Fish to Design Optimal Water Conservation Strategies

博士论文研究：了解间歇性水源及其对鱼类的影响，以设计最佳节水策略

• 批准号: 1434309
• 负责人: Laurel Larsen
• 金额: $ 1.6万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2017-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1434309&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Understanding; Intermittent

A major question in water resources is how to provide water for human uses while maintaining streamflow that sustains riverine ecosystems and fisheries. Intermittent streams, which provide habitat for salmonid fishes and water resources for agriculture, dry up into a series of disconnected pools in the late summer. To alleviate pressure on rivers and conserve habitat for juvenile salmon on the brink of extinction, communities are increasingly examining water conservation alternatives such as rainwater harvesting and groundwater recharge. Recent pilot projects provide a timely and unprecedented opportunity to address interdisciplinary questions about linkages among environmental variables, ecosystem services, and optimal management of increasingly scarce water resources. This project is expected to produce novel contributions to fundamental science, including understanding processes related to fish survival and the interactions among carbon decomposition, streamflow, and sediment transport in intermittent streams. By relating salmonid survival to predictable environmental characteristics and creating a better understanding of these critical variables, the research findings are likely to have applicability to seasonally dry watersheds region-and nation-wide. The project will facilitate mutually beneficial interactions between scientists and multiple stakeholder groups, who will also benefit from new e-tools for managing their natural resources. Findings will be disseminated through scholarly publications and at regional symposia as well as through documents developed for stakeholders and a citizen science web portal.This project specifically addresses a fundamental knowledge gap: what habitat conditions cause salmonids to disappear from some pools during the summer dry period? This project builds on a two-year field study in two tributaries of Salmon Creek (Sonoma Co., CA): Tannery Creek, which flows throughout the summer, and Fay Creek, which tends to dry into a series of isolated pools. Through extensive sampling in these adjacent streams, this research will test the hypothesis that accumulation of organic material in poorly flushed pools drives declining dissolved oxygen associated with a subsequent loss of salmonids. Fish surveys in the two tributaries will be paired with measurements of temperature, dissolved oxygen, water depth and velocity, pool volume, and organic carbon concentrations and quality. More intensive studies, focused on monitoring how these attributes change as the stream dries and determining which aquifers sustain sanctuary pools, will be conducted in four study river segments. Using linear mixing models, this research will quantify groundwater contributions and flowpaths to pools that provide critical refugia for salmon, and identify aquifers that should be targeted for enhanced infiltration. This work will also evaluate how rainwater harvesting will impact salmonid habitat with and without managed groundwater recharge. As a Doctoral Dissertation Research Improvement award, this project will provide support to enable a promising student to establish an independent research career. Increased understanding of interactions between groundwater and streamflow will enable residents and resource conservation districts to target water conservation and rainwater harvesting projects where they will yield the greatest benefit to stream ecosystems. Scientists working on salmonid recovery will benefit from increased access to local knowledge and observations via facilitated collaborative workshops and project-developed citizen science dissemination tools.

水资源的一个主要问题是如何为人类提供水，同时维持维持河流生态系统和渔业的水流。断断续续的溪流为鲑科鱼类提供了栖息地，也为农业提供了水资源，但在夏末，它们会干涸，形成一系列互不相连的水池。为了减轻河流的压力并保护濒临灭绝的幼鲑鱼的栖息地，社区越来越多地研究节水替代方案，例如雨水收集和地下水补给。最近的试点项目提供了一个及时且前所未有的机会来解决有关环境变量、生态系统服务和日益稀缺的水资源的优化管理之间的联系的跨学科问题。该项目预计将为基础科学做出新的贡献，包括了解与鱼类生存相关的过程以及间歇性溪流中碳分解、水流和沉积物运输之间的相互作用。通过将鲑鱼的生存与可预测的环境特征联系起来，并更好地了解这些关键变量，研究结果可能适用于区域和全国范围内的季节性干旱流域。该项目将促进科学家和多个利益相关群体之间的互利互动，他们也将受益于管理自然资源的新电子工具。研究结果将通过学术出版物和区域研讨会以及为利益相关者和公民科学门户网站编写的文件进行传播。该项目专门解决了一个基本知识差距：什么栖息地条件导致鲑科鱼在夏季干旱期间从一些水池中消失？该项目建立在对鲑鱼溪（加利福尼亚州索诺玛县）两条支流进行的为期两年的实地研究的基础上：坦纳里溪（Tannery Creek）在整个夏季流动，费伊溪（Fay Creek）往往干涸成一系列孤立的水池。通过对这些邻近溪流进行广泛采样，这项研究将检验以下假设：冲洗不良的水池中有机物质的积累会导致溶解氧下降，进而导致鲑科鱼的损失。两条支流的鱼类调查将与温度、溶解氧、水深和流速、水池容量以及有机碳浓度和质量的测量相结合。将在四个研究河段进行更深入的研究，重点是监测这些属性随着河流干涸如何变化，并确定哪些含水层维持保护区水池。这项研究将使用线性混合模型来量化地下水的贡献和为鲑鱼提供关键栖息地的水池的流动路径，并确定应加强渗透的目标含水层。这项工作还将评估在有或没有管理地下水补给的情况下，雨水收集将如何影响鲑鱼栖息地。作为博士论文研究改进奖，该项目将为有前途的学生建立独立的研究生涯提供支持。加深对地下水和溪流之间相互作用的了解将使居民和资源保护区能够针对水源保护和雨水收集项目，为溪流生态系统带来最大的效益。通过促进合作研讨会和项目开发的公民科学传播工具，致力于鲑鱼恢复的科学家将受益于更多地获取当地知识和观察结果。