Collaborative Research: The role of temporally varying specific storage on confined aquifer dynamics

随着气候变化、人口增长和工业化加剧缺水现象，获得清洁饮用水仍然是一个日益令人关切的问题。为了应对日益减少的地表水供应，许多地区转向了来自多孔岩石或沉积物的水，这些岩石或沉积物被称为含水层，拥有世界上大部分液态淡水。承压含水层通常很深，压力很大，世界含水层中的大部分淡水都来自承压含水层。鉴于抽水和气候变化等人类活动的变化，预测承压含水层的储水量是增加、减少还是保持不变，对于保护含水层以供未来使用至关重要，但估计一直具有挑战性。承压含水层储水量的变化通常由一个被称为储水量的参数来估计，该参数是通过乘以在井中测量的水位的变化而获得的。在这个项目中，研究人员将确定储水量如何随空间和时间变化，以及储水量的准确估计如何帮助科学家和工程师准确估计含水层储量，并提高我们有效管理地下水使用的能力。在承压含水层中，储水量可能随着时间的推移而显著变化，如果假定储水量不变，则导致传统地下水模型中的预测不准确。从卫星上可以观察到的粘土层的紧实度会导致储藏性的变化。如果存在粘土，假设储水量是恒定的，可能会导致对含水层补给的过于乐观的估计，如果在管理实践中实施，可能会导致含水层迅速枯竭。在这项研究中，研究人员将为犹他州的帕罗文山谷开发地下水模型，该地区的地下水使用受到很好的限制，与世界上其他高使用率的含水层有相似之处。他们将开发两种类型的模型，(1)假设储存量恒定的传统模型，以及(2)允许储存量随时间变化的更健壮的模型，并将模型性能与油井测量和卫星数据进行比较。通过这项研究，科学家将量化随时间变化的储水量对含水层储存的影响，并有助于改进对补给量和含水层参数(如水力传导性)的估计。在项目期间，他们将与社区利益攸关方合作，并在研究和科学交流方面培训研究生和本科生。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。

Access to clean drinking water continues to be a growing concern as climate change, population growth and industrialization increase the prevalence of water scarcity. In response to dwindling surface water supply, many regions turn to water from porous rocks or sediments known as aquifers that hold most of the world’s liquid freshwater. Confined aquifers, which are typically deep and pressurized, hold the majority of freshwater in the world’s aquifers. Predicting whether water storage in a confined aquifer will increase, decrease, or remain constant given variations in human activity such as pumping, and climate change is critical for preserving aquifers for future use, but has been challenging to estimate. Changes in confined aquifer storage are typically estimated by a parameter known as storativity, which is obtained by multiplying changes in water levels measured in wells. In this project, the researchers will determine how storativity changes over space and time, and how accurate estimation of storativity can help scientists and engineers to accurately estimate aquifer storage, and improve our ability to effectively manage groundwater use. In confined aquifers, storativity can vary significantly over time, leading to inaccurate predictions in traditional groundwater models if the storativity is assumed constant. The compaction of clay layers, which can be observed from satellites, causes changes in storativity. If clays are present, assuming that storativity is constant can lead to overly optimistic estimates of aquifer recharge which, if implemented in management practices, could result in rapid aquifer depletion. In this research, the investigators will develop groundwater models for the Parowan Valley in Utah, a region with well-constrained groundwater use, and that shares similarities with other high-use aquifers of the world. They will develop two types of models, (1) traditional models that assume constant storativity, and (2) more robust models that allow storativity to vary with time and compare the model performance against well measurements and satellite data. Through this research, scientists will quantify the effect that time-varying storativity has on aquifer storage, and contribute to improving estimates of recharge and aquifer parameters such as hydraulic conductivity. During the project, they will collaborate and work with community stakeholders, and train graduate and undergraduate students in both research and science communication.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.