Developing a Novel Approach for Identifying Geologic Controls on Groundwater Flow

地下水为世界上近一半的人口服务，灌溉着38%的农业用地，地下水资源的压力越来越大。在美国，对成千上万受污染的地下水场地进行更有效的管理和补救是至关重要的。负责任地、经济有效地管理这些地点，需要准确地描述水文地层学，它描述了地下不同沉积物和岩石的分布对地下水流动的控制。这项研究将开发一种新的方法，该方法依赖于收集井中的水位，结合使用领先的地下水监测技术来表征水文地层学。新方法将在一个地下水被有机化学混合物污染的现场进行测试。学员将练习技术技能、科学交流、项目管理技能，并学习将研究成果应用于现场决策。这项研究的地下水监测技术将被转移到一个户外教学设施，为爱荷华大学的学生提供在他们的课程和本科研究中使用该技术的机会。本研究的目标是开发一种利用直接水力数据集（即井中的水位）阐明地下水文地层单位的方法。水位数据将每10秒收集一次，从地下10到15个不同深度的每个监测点使用称为多级系统的井。这些数据将显示在雨水渗透和/或抽水变化期间，水位对垂直地下水流量变化的响应。响应数据将突出显示不同水文地层单元的边界和厚度。其他补充数据集和计算机模型将用于评估使用这种新方法确定的水文地层学和使用标准方法开发的水文地层学的准确性。其结果将是创造一种改进的方法来描述适用于所有地下水环境的水文地层学特征。这一发现将减少地下水流动和污染物迁移模拟中的不确定性，并为随着对地下水资源需求的增加而管理受污染场地提供更好的基础。该项目由水文科学计划、刺激竞争性研究的既定计划（EPSCoR）和地球科学仪器和设施计划共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Groundwater serves almost half the world’s population and irrigates 38% of agricultural land and there is increased strain on groundwater resource. In the United States, more effective management and remediation of the thousands of polluted groundwater sites will be critical. Managing these sites, responsibly and cost effectively, requires accurate description of the hydrostratigraphy, which describes the control that the distribution of different sediments and rocks in the subsurface has on groundwater flow. This research will develop a new approach that relies on collecting water levels in wells using a combination of leading-edge groundwater monitoring technologies to characterize hydrostratigraphy. The new approach will be tested at a field site where groundwater is contaminated by a mixture of organic chemicals. Student trainees will practice technical skills, science communication, project management skills, and learn to apply research results to inform site decisions. The groundwater monitoring technology from this research will be transferred to an outdoor teaching facility to provide students across the University of Iowa the opportunity to use the technology in their courses and undergraduate research. The goal of this research is to develop an approach to elucidate hydrostratigraphic units in the subsurface using a direct hydraulic dataset (i.e., water levels in wells). Water level data will be collected every 10 seconds from 10 to 15 distinct depths in the subsurface at every monitoring location using wells called multilevel systems. These data will show the response of water levels to changes in vertical groundwater flow during rainwater infiltration and/or changes in pumping. The response data will highlight the boundaries and thicknesses of distinct hydrostratigraphic units. Other complementary data sets and a computer model will be used to evaluate the accuracy of the hydrostratigraphy determined using this new approach and hydrostratigraphy developed using standard methods. The outcome will be the creation of an improved approach to characterizing hydrostratigraphy that is applicable to all groundwater settings. The findings will reduce uncertainty in simulations of groundwater flow and contaminant migration and provide a better basis for managing contaminated sites as demands on groundwater resources increase. This project is jointly funded by Hydrologic Sciences program, the Established Program to Stimulate Competitive Research (EPSCoR), and the Earth Sciences Instrumentation and Facilities 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.