EAR-PF: Constraining Paired Air-Water Temperature Models' Efficacy In Head and Intermediate Watersheds With Groundwater and Bedrock Assessment and Multi-Decade Temperature Records

气候变化导致大气温度升高，从而改变地下水和溪流的温度模式，导致水质和生态多样性下降。在美国东部的部分地区，如西弗吉尼亚州，气候在上个世纪已经变暖了 0.5° – 1.0°F，预计到 2100 年气温将再上升 3° – 4°F，进一步变暖溪流和浅层地下水温度并影响生活在那里的生物。河流温度模式可以让我们深入了解这些河流和流域对气温升高的脆弱性。然而，当前的模型并没有完全考虑地表和地下水相互作用引起的温度变化。气候变化中地下水和地表水温度的模型预测必须考虑影响热信号的因素，包括气候、地质、水文、土地利用和土地覆盖。数据显示，因气候变化而导致的河流温度变化可能（部分）是由地下水排放的相对贡献和温度的变化驱动的。自 1958 年以来，西弗吉尼亚州的费尔诺实验森林 (FEF) 一直在记录至少 10 个源头流域的温度数据。Riddell 将使用 FEF 作为控制良好的室外实验室来研究这些温度模式，从而生成改进的模型并更好地了解这些系统。改进的模型可用于估计流域对干旱或高强度降水事件以及洪水等相关灾害的反应。通过与国家青年科学基金会（NYSF）的合作，这项工作将直接影响西弗吉尼亚州的初中和高中学生。这项拟议的工作位于莫农加希拉国家森林，国家青年科学基金会自 1963 年以来一直在这里举办国家青年科学营。FEF 靠近该营地和新购买的位于西弗吉尼亚州戴维斯的国家青年科学中心 (NYSCenter)。在该项目期间，与 NYSF 工作人员的合作将在黑水河上安装一个流量计监测站，该监测站毗邻 NYSCenter，为西弗吉尼亚州的中学生和高中生提供水文教育。此次合作将支持 NYSF 的使命，即培养和保持学生对 STEM 领域的兴趣，提高高中保留率和追求中学后 STEM 教育。气候变化导致大气温度升高，从而改变地下水和溪流的热模式，导致水质和生态多样性下降。地表水中的热状况很大程度上受到地下水及其与地表的连通性的影响，这可以通过比较空气和溪流温度记录来辨别。通过正弦波回归进行配对空气-水温分析是一种表征气温与地表水温之间关系的方法，可阐明地下水对流域水力学、冷水栖息地以及地下水温度对气候变化的响应的贡献。最近的研究重点是对年度配对空气/水温信号进行建模，以评估地下水在将空气温度传播到从次流域到大陆尺度的水流中的作用。这些正弦回归研究的结果侧重于通过比较空气和水温记录的振幅比（正弦曲线峰值高度）和相位滞后信号（峰值之间的时间）来确定地下水对地表水的输入以及地表水对气候变化的最终响应。较深的地下水特征显示年温度变化很小，并且具有不明确的振幅比和相位滞后，而浅层地下水特征显示出高振幅比和可测量的天量级相位滞后。然而，当前的模型并未完全考虑影响河流温度的地下水与地表水的相互作用。这些过程受含水层特征的控制，例如含水层厚度、孔隙度、导水率以及基岩类型和深度。本研究将利用西弗吉尼亚州的 Fernow 实验森林，通过收集新的地下水温度测量值，评估同一流域中不同基岩地质的影响，并探索这些模型在水文相连、嵌套流域以及空气和河流温度记录存在数十年的流域中的有效性，来提高中小型流域的热流模型功效。这项研究将增进人们对地下水对源头流域和流入的中间流域的贡献以及这些流域对气候变化的脆弱性的了解。当前应用于大型大陆流域的模型（正弦回归）认识到当地水文地质学和地质学对地下水行为以及随后对地表河流温度模式的影响的重要性。然而，目前还没有研究深入描述小流域的地表水文学、水文地质学和基岩地质学以及所有这些因素对河流温度模式的贡献。这项研究将填补这一空白，并强调在对地表进行预测时表征地下特征的重要性。该项目由地球科学博士后奖学金计划、刺激竞争研究既定计划 (EPSCoR) 和水文科学计划共同资助。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。

Climate change increases atmospheric temperatures, which alters temperature patterns in groundwater and streams and results in reduced water quality and ecological diversity. In parts of the eastern United States, like West Virginia, climate has already warmed 0.5º – 1.0º F over the last century and temperatures are expected to rise another 3º – 4º F by the year 2100, further warming stream and shallow groundwater temperatures and affecting the organisms that live there. Stream temperature patterns provide insight into the vulnerability of these streams and watersheds to warming temperatures. However, current models do not fully account for temperature changes caused by interactions of water on the surface and underground. Model predictions of ground and surface water temperatures in a changing climate must be informed by the factors that influence thermal signals, including climate, geology, hydrology, land use, and land cover. Data show stream temperature changes in response to changing climate are likely driven (in part) by changes in relative contributions and temperatures of discharging groundwater. The Fernow Experimental Forest (FEF) in West Virginia has been recording temperature data in at least ten headwater watersheds since 1958. Using the FEF as a well-controlled outdoor laboratory to study these temperature patterns, Riddell will generate improved models and better knowledge of these systems. Improved models can be used to estimate watershed responses to drought or high intensity precipitation events, and associated disasters such as flooding. This work will directly impact middle and high school high school students in WV through collaboration with the National Youth Science Foundation (NYSF). This proposed work is in the Monongahela National Forest where the National Youth Science Foundation has hosted its National Youth Science Camp since 1963. The FEF is close to the camp and the newly purchased National Youth Science Center (NYSCenter) in Davis, WV. During this project, collaboration with NYSF staff will result in the installation of a stream gage monitoring station on the Blackwater River, which is adjacent to the NYSCenter to deliver hydrology education to middle and high school students in WV. This collaboration will support the NYSF mission to build and maintain student interest in STEM fields and promote high school retention rates and the pursuance of post-secondary STEM education.Climate change is increasing atmospheric temperatures which alters thermal patterns in groundwater and streams, resulting in reduced water quality and ecological diversity. Thermal regimes in surface waters are highly influenced by groundwater and its connectivity to the surface, which may be discerned by comparing air and stream temperature records. Paired air-water temperature analysis via sine wave regression is a way to characterize the relationship between air temperature and surface water temperature to elucidate the groundwater contributions to watershed hydraulics, cold-water habitat refugia, and groundwater temperature response to climate change. Recent research has focused on modeling annual paired-air/water temperature signals to assess the role of groundwater in propagating air temperature to stream water from sub-watershed to continental scales. Results of these sine regression studies are focused on determining the inputs of groundwater to surface water and the eventual response of surface water to climate change by comparing the amplitude ratios (sine curve peak height) and phase lag signals (time between peaks) of air and water temperature records. Deeper groundwater signatures show little variation in annual temperature and have ambiguous amplitude ratio and phase lag whereas shallow groundwater signatures show high amplitude ratios and measurable phase lag on the order of days. However, current models do not fully account for groundwater – surface water interactions that influence stream temperatures. These processes are governed by aquifer characteristics such as aquifer thickness, porosity, hydraulic conductivity, and bedrock type and depth. This study will utilize the Fernow Experimental Forest in WV to improve thermal stream model efficacy in small and intermediate watersheds by collecting new groundwater temperature measurements, assessing the influence of differing bedrock geology in the same watershed, and exploring the efficacy of these models in hydrologically connected, nested watersheds and in watersheds in which air and stream temperature records exist across multiple decades. This study will advance the knowledge of groundwater contributions to headwater watersheds and intermediate watersheds into which they discharge and to the vulnerability of these watersheds to climate change. The current models (sine regression) being applied to large, continental size watersheds recognize the importance of local hydrogeology and geology on groundwater behavior and the subsequent effects on surface stream temperature patterns. However, no study has yet to intensively characterize the surface hydrology, hydrogeology, and bedrock geology of small watersheds and the contribution of all these factors on stream temperature patterns. This study will fill that gap and highlight the importance of characterizing the subsurface when making predictions about the surface. This project is jointly funded by the Earth Sciences Postdoctoral Fellowship program, the Established Program to Stimulate Competitive Research (EPSCoR) and the Hydrologic Sciences program.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.