Doctoral Dissertation Research: Modeling Basin-Scale Snow Water Equivalent: Present Day and Projected Future Impacts on Stream Flow in the Oregon Cascades

以融雪为主的喀斯喀特山脉为农业、生态系统和市政当局提供了至关重要的供水。在整个太平洋西北地区，预测气候变化影响的分析表明，气温上升导致积雪减少，预计这将导致夏季河流流量下降。麦肯齐河流域位于俄勒冈州喀斯喀特山脉的中西部，具有美国西部许多河流系统的典型特征。在这个流域，农民、鱼类、水电和市政用户争夺有限的供水，特别是在夏季，当河流内流量达到最低时。未来的气候预估预计冬季会更温暖、更潮湿，夏季会更长、更干燥，但这些区域预估的流域尺度影响尚未得到很好的理解。虽然几十年来一直在局部尺度上测量积雪量，但目前还没有对整个流域的积雪量进行精确测量。由于缺乏流域尺度的供水预测，水资源管理者在面对气候变化时缺乏有效规划的决策支持工具。本博士论文研究项目将采用定量和定性相结合的研究方法(1)量化麦肯齐河流域的全流域雪水当量分布和未来潜在气候情景的年代际水当量项目分布；(2)在年代际尺度上量化麦肯齐河流域上游积雪对河流流量的贡献和项目对河流流量的影响；(3)设计并测试由用户输入形成的“水文仪表板”的有效性，以向广泛的利益相关者传播科学信息。该研究项目将提供俄勒冈瀑布空间分布雪水当量的第一个定量表示。它将预测未来雪水当量的分布，并预测这些影响将如何影响河流流量。由于图形水文仪表板的开发将由利益相关者（包括联邦、州和地方机构、公用事业和非营利组织）的投入驱动，这个决策支持工具应该提高研究的可及性和显著性，并为水资源管理者提供有价值的信息。该项目还应帮助科学家学习如何更好地传播他们的研究成果。作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立研究生涯。

The snowmelt-dominated Cascade Mountains provide critical water supply for agriculture, ecosystems, and municipalities. Throughout the Pacific Northwest, analyses of projected climate change impacts show rising temperatures resulting in diminished snowpacks, which is expected to lead to declines in summertime in-stream flow. The McKenzie River basin, which is located in the central western Cascades of Oregon, exhibits characteristics typical of many river systems in the western United States. In this watershed, farmers, fish, hydropower, and municipal users compete for a limited supply of water, especially in summer when in-stream flows reach a minimum. Future climate projections anticipate warmer but wetter winters and longer, drier summers, but watershed-scale impacts of these regional projections are not well understood. While snowpack has been measured at the local scale for decades, accurate basin-wide measurements of snowpack do not exist. The lack of basin-scale water supply projections leave water resource managers without decision-support tools to plan effectively in the face of climate change. This doctoral dissertation research project will use a mix of quantitative and qualitative research methods (1) to quantify the basin-wide distribution of snow-water equivalent for the McKenzie River watershed and project distributions of -water equivalent for potential future climate scenarios on the decadal scale; (2) quantify snowpack contributions to streamflow in the upper reaches of the McKenzie River watershed and project impacts on stream flow for potential future climate scenarios on the decadal scale; and (3) design and test the effectiveness of a "hydrologic dashboard" shaped by user input to disseminate scientific information to a broad base of stakeholders.This research project will provide the first quantitative representation of spatially distributed snow-water equivalent in the Oregon Cascades. It will project future distributions of snow-water equivalent and predict how these impacts will affect stream flow. Because the development of the graphical hydrologic dashboard will be driven by stakeholder input (including federal, state, and local agencies; public utilities; and non-profit organizations), this decision-support tool should improve the accessibility and saliency of the research and provide water resource managers with valuable information. The project should also assist scientists in learning how to better disseminate their research results. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.