Collaborative Research: Biogeochemical and Hydrologic Controls on Solutes and Flowpaths in Alpine Watersheds

这项研究将阐明在高山盆地分水岭尺度上重要的地球化学和生物地球化学过程。它将使用一种多学科方法来审查这些过程，该方法结合了稳定和放射性同位素示踪剂、情节水平实验、过程水平模拟和实地研究，以限制模拟结果。新的同位素工具将与水质和水量的实地测量相结合，以分离溪水中大气和土壤来源的硝酸盐的相对贡献，增加我们对控制碱度的生物地球化学反应的理解，并提供对硫沉积动力学的洞察。一个关键目标是根据基本原则建立一个强有力的溶质运移模型，以预测各种化学成分在许多地点和各种条件下的命运。相关的地球化学、生物地球化学和水文过程在分水岭尺度上是相互关联的，因此必须共同研究。用于这个基于物理的数学模型的算法提供了一种集成的方法来模拟季节性积雪覆盖的高山盆地的水文和生物地球化学，模型开发和野外工作密不可分。这项研究将有助于更好地从根本上理解生物地球化学和地球化学过程，这些过程可以用来响应人为扰动。这个多学科研究团队得到了美国国家生物服务局、美国地质调查局、国家公园管理局和长期生态研究计划的合作支持。这两个研究区域是位于科罗拉多州前缘山脉东坡的尼沃特岭/绿色湖谷和洛克谷流域。

This research will elucidate geochemical and biogeochemical processes that are important at the watershed scale in alpine basins. It will examine these processes using a multidisciplinary approach that combines stable and radiogenic isotopic tracers, plot level experiments, process-level modeling, and field research to constrain the modeling results. New isotopic tools will be used in combination with field measurements of water quality and quantity to separate the relative contributions of atmospheric and soil-derived sources of nitrate in streamwaters, increase our understanding of the biogeochemical reactions controlling alkalinity, and provide insights into the dynamics of sulfur deposition. A key objective is the development of a robust model for solute transport built on fundamental principles to predict the fate of a variety of chemical constituents at many sites and under a variety of conditions. The relevant geochemical, biogeochemical and hydrologic processes are interconnected at the watershed scale and therefore must be studied together. The algorithms used for this ph ysically-based mathematical model provide an integrated approach to modeling the hydrology and biogeochemistry of seasonally snow-covered alpine basins with model development and field work inextricably linked. This research will contribute to a better fundamental understanding of the biogeochemical and geochemical processes, which can be used in responding to anthropogenic perturbations. The multidisciplinary research team has cooperative support from the National Biological Service, U.S. Geological Survey, the National Park Service, and the Long-Term Ecological Research Program. The two study areas are Niwot Ridge/Green Lakes Valley and Lock Vale Watershed, which lie on the east slope of the Colorado Front Range.