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

气候变化提高了大气温度，从而改变了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，比如西弗吉尼亚州，气候在过去一个世纪里已经变暖了0.5摄氏度到1.0华氏度，预计到2100年，气温还会再上升3摄氏度到4华氏度，使溪流和浅层地下水的温度进一步变暖，并影响生活在那里的生物。溪流温度模式提供了对这些溪流和分水岭受气温变暖影响的脆弱性的洞察。然而，目前的模型没有完全考虑到地表和地下水的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、水文学、土地利用和土地覆盖。数据显示，河流温度对气候变化的响应可能(部分)受到地下水排放相对贡献率和温度变化的推动。自1958年以来，西弗吉尼亚州的费诺实验森林(FEF)已经记录了至少10个源头流域的温度数据。利用FEF作为一个控制良好的室外实验室来研究这些温度模式，Riddell将产生更好的模型和对这些系统的更好知识。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相关灾害(如洪水)的反应。这项工作将通过与国家青年科学基金会(NYSF)的合作直接影响西弗吉尼亚州的初中生和高中生。这项拟议的工作是在莫农加赫拉国家森林开展的，自1963年以来，国家青年科学基金会一直在那里举办国家青年科学营。FEF靠近营地和位于西弗吉尼亚州戴维斯的新购买的国家青年科学中心(NYSCenter)。在该项目期间，将与NYSF工作人员合作，在毗邻NYS中心的Blackwater河上安装一个水流量监测站，为西弗吉尼亚州的初中生和高中生提供水文教育。这项合作将支持NYSF的使命，以建立和保持学生对STEM领域的兴趣，并促进高中保留率和对中学后STEM教育的追求。气候变化正在提高大气温度，这改变了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水温记录来辨别。基于正弦波回归的空气-水温配对分析是一种表征气温和地表水温度之间关系的方法，以阐明地下水对流域水力学、冷水栖息地避难所和地下水温度对气候变化的响应。最近的研究侧重于对年度成对的空气/水温信号进行模拟，以评估地下水在将空气温度从分流域传播到大陆尺度上的作用。这些正弦回归研究的结果集中于通过比较气温和水温记录的幅度比(正弦曲线峰值高度)和相位滞后信号(峰值间隔时间)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。深层地下水特征显示年温度变化不大，具有模糊的幅值比和相位滞后，而浅层地下水特征在天的数量级上表现出高的幅值比和可测量的相位滞后。然而，目前的模型没有完全考虑地下水和地表水之间的相互作用，这些相互作用会影响河流的温度。这些过程受含水层特性的支配，例如含水层厚度、孔隙度、水力传导性以及基岩类型和深度。这项研究将利用西弗吉尼亚州的费诺实验森林，通过收集新的地下水温度测量数据，评估同一流域不同基岩地质的影响，并探索这些模型在水文相连的嵌套流域以及存在数十年空气和气流温度记录的流域中的有效性，来提高中小流域的热流模型效率。这项研究将增进对地下水对其排放到的源头流域和中间流域的贡献以及这些流域对气候变化脆弱性的认识。目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和地质对地下水行为以及随后对地表水温模式的影响的重要性。然而，还没有研究深入地描述小流域的地表水文、水文地质和基岩地质，以及所有这些因素对水温模式的贡献。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表面的重要性。该项目由地球科学博士后奖学金计划、已建立的激励竞争性研究计划(EPSCoR)和水文科学计划联合资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.