The influence of hierarchical and multiscale river morphology and sediment heterogeneity on hyporheic exchange processes

当河水和地下水混合时，溶质、热量和其他溶解成分沿河流沿着相互作用，通常称为潜流交换。潜流区内的过程有可能减轻河流中的污染物负荷并改善水质。这些过程取决于河道的形状和沉积物类型的分布，因此在空间和时间上各不相同。该项目将把联合收割机创新的实地测量与先进的计算机模型相结合，以深入了解沉积物异质性和河道形态对溶质通量和养分循环的影响。这项研究的结果将在水资源管理中得到实际应用，并将指导优化地表水和地下水质量的战略。该项目将使用位于辛辛那提大学的Theis环境监测和建模站点。现场的实践活动将激发学生的兴趣，并为与水有关的STEM职业做好准备。一组不同的K-12学生将通过与辛辛那提博物馆中心合作开发的水项目获得实践经验，该项目的目标是提供多尺度沉积物异质性和河道形态如何控制潜流交换过程的见解，并提高数值模型预测潜流通量，溶质停留时间和由此产生的非地球化学转化的空间模式的能力。该项目将利用创新的实地观测来开发和验证多尺度数值模型。该项目的主要目标是：（1）量化多尺度河流形态和相关的地层结构对潜流通量和溶质停留时间的控制影响，并确定尺度的相关性：（2）确定多尺度河流形态和地层结构如何影响潜流带内的地球化学反应动力学;以及（3）确定哪些异质性和形态属性对于理解和准确预测潜流交换过程是最重要的。该奖项反映了NSF的法定使命，并通过利用基金会的智力价值进行评估而被认为值得支持和更广泛的影响审查标准。

Solutes, heat, and other dissolved constituents interact along rivers as river water and groundwater mix, often referred to as hyporheic exchange. Processes within the hyporheic zone have the potential to mitigate contaminant loads in rivers and improve water quality. These processes depend on the shape of the channel and the distribution of sediment types and thus vary across space and time. This project will combine innovative field measurements with advanced computer models to provide insights into the influence of sediment heterogeneity and river channel morphology on solute fluxes and nutrient cycling. Results of this research will have practical applications in water resource management, and will guide strategies to optimize both surface water and groundwater quality. The project will use the Theis Environmental Monitoring and Modeling Site at the University of Cincinnati. Hands-on activities at the site will stimulate student interest, and prepare them for water-related STEM careers. A diverse group of K-12 students will receive hands-on experience through a water program developed in partnership with the Cincinnati Museum Center.The project goal is to provide insights into how multiscale sediment heterogeneity and river channel morphology control hyporheic exchange processes, and to improve the capacity of numerical models to predict spatial patterns of hyporheic flux, solute residence times, and resulting biogeochemical transformations. The project will utilize innovative field observations to develop and validate multiscale numerical models. The project will address several primary goals: (1) quantify the controlling influence of multiscale fluvial forms and associated stratal architecture on hyporheic flux and solute residence times, and determine the relevance of scales; (2) determine how multiscale fluvial forms and stratal architecture influence biogeochemical reaction dynamics within the hyporheic zone; and (3) identify which heterogeneity and morphologic attributes are most essential for understanding and accurately predicting hyporheic exchange processes.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.