Postdoctoral Fellowship: EAR-PF: Feedbacks Between Controls of Stream Dry-Down Responses at the Rain-Snow Transition

博士后奖学金：EAR-PF：雨雪转变时河流干涸响应控制之间的反馈

• 批准号: 2305601
• 负责人: Maggi Kraft
• 金额: $ 18万
• 依托单位: Kraft, Maggi A
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2305601&HistoricalAwards=false
• 关键词: Postdoctoral; Fellowship; EAR; PF; Feedbacks

Dr. Maggi Kraft has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out research and professional development activities under the mentorship of Dr. Sarah Godsey at Idaho State University. The western United States relies on snow for water resources. In the same region, the majority of streams fed by snowmelt and rain are non-perennial with streamflow disappearing for at least a portion of the year. Warming global temperatures are shifting the precipitation phase from snow to rain, but the impacts of shifting snowfall fraction in non-perennial streams are not clear. This research will merge concepts of snowmelt processes, vegetation dynamics, and soil properties across three watersheds spanning the rain-snow transition to understand how precipitation phase affects stream wetting and drying. These interactions are particularly important in controlling streamflow responses across the rain-snow transition where vegetation, snow, and soils are interrelated and sensitive to changing temperatures. While these concepts have been evaluated in a piecewise manner, they have not yet been integrated to allow us to accurately predict non-perennial streamflow response to changing snow inputs. This research will advance the science of non-perennial stream ecosystems and provide relevant information for managing natural resources. Additionally, this project will develop two education and outreach opportunities via developing and leading a workshop focused on the analysis of streamflow presence-absence data and mentoring an undergraduate student to develop, implement and present an interdisciplinary research project. Non-perennial streamflow response to shifts in snow represents a fundamental gap in our understanding of hydrologic behavior. Watersheds spanning the rain-snow transition, where precipitation shifts phase between snow and rain, provide an ideal location to study streamflow response to the shifting precipitation phase. Across the rain-snow transition feedbacks between vegetation, snow, and soil are interrelated thus, evaluation of coupled observations is needed to accurately predict streamflow response to changing snow water availability. However, there is a lack of integrated studies linking daily signals of snowmelt, transpiration, and soil moisture in non-perennial watersheds. The focus of this research is to study the response of non-perennial stream dry-down and wet-up to interactions between snow, rain, vegetation, and soils. This research will be carried out in three watersheds spanning the rain-snow transition in the semi-arid western U.S. using measurements of snow depth, sap flux, stream water presence-absence, soil moisture, and high-resolution satellite imagery. The satellite-derived and ground-based snowmelt, transpiration, and soil moisture observations will be compared to the annual and diel stream wet-dry cycle response. High-resolution soil depth maps will be created to evaluate how soil water capacity, snow storage, and vegetation modulate rain or snow water inputs and non-perennial streamflow. This research will advance the science of non-perennial stream ecosystems and provide relevant information for managing natural resources.This project is jointly funded by the Division of Earth Science Postdoctoral Fellowship Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Maggi Kraft 博士获得了 NSF 地球科学博士后奖学金，在爱达荷州立大学 Sarah Godsey 博士的指导下开展研究和专业发展活动。美国西部依靠雪来获取水资源。在同一地区，大部分由融雪和雨水注入的溪流都是非常年溪流，一年中至少有一段时间水流消失。全球气温变暖正在将降水阶段从雪转变为雨，但非常年溪流降雪比例变化的影响尚不清楚。这项研究将融合跨越雨雪过渡的三个流域的融雪过程、植被动态和土壤特性的概念，以了解降水阶段如何影响河流的湿润和干燥。这些相互作用对于控制雨雪过渡期间的水流响应特别重要，在雨雪过渡期间，植被、雪和土壤相互关联并对温度变化敏感。虽然这些概念已经以分段的方式进行了评估，但它们还没有被整合起来，使我们能够准确预测非常年径流对变化的雪输入的响应。这项研究将推进非常年河流生态系统的科学发展，并为管理自然资源提供相关信息。此外，该项目还将通过开发和领导一个研讨会来开发两个教育和推广机会，该研讨会的重点是分析流流存在-缺席数据，并指导本科生开发、实施和展示跨学科研究项目。非常年径流对雪变化的响应代表了我们对水文行为理解的根本差距。跨越雨雪过渡的流域，降水在雪和雨之间变换相位，为研究水流对变换的降水相位的响应提供了理想的位置。在雨雪转变过程中，植被、雪和土壤之间的反馈是相互关联的，因此需要对耦合观测进行评估，以准确预测水流对雪水可用性变化的响应。然而，缺乏将非常年流域的每日融雪、蒸腾和土壤湿度信号联系起来的综合研究。这项研究的重点是研究非常年河流干涸和湿润对雪、雨、植被和土壤之间相互作用的响应。这项研究将在美国半干旱西部跨越雨雪过渡期的三个流域进行，利用雪深、树液通量、溪流水存在与否、土壤湿度和高分辨率卫星图像的测量。卫星和地面的融雪、蒸腾和土壤湿度观测结果将与年度和昼流干湿循环响应进行比较。将创建高分辨率土壤深度图，以评估土壤水容量、积雪和植被如何调节雨雪水输入和非常年水流。这项研究将推进非常年河流生态系统的科学发展，并为管理自然资源提供相关信息。该项目由地球科学部博士后奖学金计划和刺激竞争性研究既定计划（EPSCoR）共同资助。该奖项反映了通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。