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

由于气候变化、人口增长和工业化加剧了水资源短缺的普遍程度，获得清洁饮用水仍然是一个日益令人关切的问题。为了应对地表水供应的减少，许多地区转向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，这些含水层拥有世界上大部分的液态淡水。承压含水层通常很深，压力很大，储存着世界含水层中的大部分淡水。预测承压含水层中的水储存量是否会增加、减少或保持不变，因为人类活动的变化，如抽水和气候变化，对于保护含水层供未来使用至关重要，但估计起来一直很有挑战性。承压含水层储水量的变化通常通过称为储水率的参数来估计，该参数是通过乘以威尔斯中测量的水位变化而获得的。在这个项目中，研究人员将确定储水率如何随空间和时间变化，以及储水率的准确估计如何帮助科学家和工程师准确估计含水层的储水量，并提高我们有效管理地下水使用的能力。在承压含水层中，储水率随时间变化很大，如果假设储水率为常数，则传统地下水模型的预测会不准确。从卫星上可以观测到粘土层的压实，这会引起储气率的变化。如果存在粘土，假设蓄水率恒定，可能导致对含水层补给的估计过于乐观，如果在管理实践中实施，可能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Parowan山谷开发地下水模型，该地区地下水使用受到很好的限制，与世界上其他高使用含水层有相似之处。他们将开发两种类型的模型，（1）传统模型，假设恒定的存储率，（2）更强大的模型，允许存储率随时间变化，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，科学家们将量化时变蓄水率对含水层蓄水的影响，并有助于改善对补给和含水层参数（如导水率）的估计。该奖项反映了NSF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。

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.