Investigating the scales of sustainability in groundwater extraction

Katherine H. Markovich被授予NSF EAR博士后奖学金，在亚利桑那大学开展研究和教育计划。研究的主要目的是探讨地下水年龄与可持续性的关系。这两者经常被混为一谈，但目前还没有一项机制研究将抽水井中遇到的地下水年龄分布与从该井中抽取水的可持续性联系起来。这项工作将把图森的利益相关者聚集在一起，如水资源管理者、当地社区、城市居民和行业代表，以建立相互同意的地下水可持续性参数，如可接受的空间和时间透支规模。这种利益相关者参与的结果将使用居住时间估计的年龄追踪器和综合水文建模的组合进行探索。这项研究在利用先进的建模和年龄测定技术将地下水年龄与可持续性联系起来以及促进国民健康和福利方面具有重要意义，因为获得清洁水对于美国半干旱和干旱地区社区的繁荣至关重要。多种年龄示踪剂将与复杂的综合水文模型相关联，以图森地区含水层系统为例，探索地下水开采的流动路径和储存响应的完整时空尺度。将对采出井进行取样，使用常见的年龄测年示踪剂（氚-氦和碳-13）分别估算图森采出井中年轻水和年老水的比例，并使用一种新型示踪剂（氩-39）估算中间年龄比例。这三种示踪剂的结合将揭示出对一口井有贡献的流动路径的更完整分布，从而为区域含水层系统的补给和水文地质特征提供洞见。这些结果将用于通过粒子跟踪代码（EcoSLIM）验证图森地区的综合水文模型（ParFlow-CLM）。这一步骤将产生一个模型，该模型捕获了图森采油井的主要流体系统。后验模型将用于探索地下水年龄与可持续性之间的关系，并在气候变化和人口增长情景下预测这种关系。该结果将填补我们使用非重叠年龄示踪剂对井流路径分布的理解空白，并将这些结果与复杂的区域含水层模型（包括高地补给和贡献区域）联系起来。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。

Katherine H. Markovich has been granted an NSF EAR Postdoctoral Fellowship to carry out research and education plans at the University of Arizona. The key goal of the research is to investigate the relationship of groundwater age and sustainability. The two have often been conflated, but there has yet to be a mechanistic study linking the distributions of groundwater age encountered in a pumping well with the sustainability of extracting water from that well. This work will bring together stakeholders in Tucson such as water managers, native communities, urban residents, and industry representatives to establish mutually agreed upon parameters for groundwater sustainability, such as acceptable spatial and temporal scale of overdraft. The results of this stakeholder engagement will be explored using a combination of age tracers for residence time estimation and integrated hydrologic modeling. The study is important in linking groundwater age to sustainability using advanced modeling and age-dating techniques, as well as to advance national health and welfare, since access to clean water is paramount for the prosperity of communities in semi-arid and arid regions of the United States. Multiple age tracers will be linked with a sophisticated integrated hydrologic model to explore the full spatial and temporal scales of flow path and storage response to groundwater extraction, using the Tucson regional aquifer system as a case study. Extraction wells will be sampled for common age-dating tracers (Tritium-Helium and Carbon-13) to estimate the fraction of young and old water encountered in Tucson extraction wells, respectively, using a novel tracer (Argon-39) to estimate the intermediate age fraction. The integration of these three tracers will reveal a more complete distribution of flow paths contributing to a well, and thus provide insight as to the recharge and hydrogeologic characteristics of the regional aquifer system. These results will be used to validate an integrated hydrologic model (ParFlow-CLM) of the Tucson area via a particle tracking code (EcoSLIM). This step will result in a model that captures the dominant flow systems contributing to Tucson extraction wells. The posterior model will then be used to explore the relationship between groundwater age and sustainability, and project this relationship forward under climate change and population growth scenarios. This result will fill in the gaps in our understanding of flow path distributions to wells using non-overlapping age tracers and link those results to a sophisticated regional aquifer model that includes the upland recharge and contributing areas.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.