RAPID: Managed Groundwater Recharge (MAR) in a year of exceptional precipitation: Evaluating the impact of dry-well versus on-farm recharge on water quality

地下水是一种重要资源，为地球上25亿人提供饮用水，约占灌溉用水的43%。许多地区在过去几十年中经历了地下水资源的严重枯竭。地下水枯竭的加剧促使地下水含水层有意补充多余的地表水。有意地下水补给，也称为管理含水层补给（MAR）有许多好处。它可以增加地下水储存量，减少地面沉降，减轻洪水风险，防止海水入侵，帮助调节干旱季节的河流流量和河流温度，并提高整体水安全。本研究将调查两种MAR策略之间的地下水质量差异，这两种策略用于将地表水引入加利福尼亚州中央山谷的两个相邻地点的地下水系统。他们的发现将有助于未来实施有意的地下水补给策略，以改善社区的地下水质量。在加利福尼亚异常潮湿的一年，积雪和降雨的降雨量超过了正常降雨量的300%，导致了大范围的洪水，研究人员将研究利用洪水补给含水层对地下水质量的影响，在两个地点进行两种不同的MAR策略。MAR的策略是干井注入和农田地面驱油。研究人员将调查人为和地质污染物（如硝酸盐、砷、铀、铬、其他农药和大肠菌群指标）的发生、分布和浓度变化。研究人员将量化每种补给策略向地下水释放的污染物，并评估污染物动员过程与影响动员的水文地球化学条件之间的联系。本研究的结果将提高对不同含水层补给管理策略影响的理解，并为未来水管理实践中补给过程中处理和减排方案的未来发展提供信息。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 is a vital resource that provides drinking water to 2.5 billion people on earth and accounts for about 43% of the water used for irrigation. Many regions have experienced significant depletion in groundwater resources over the last decades. Increased groundwater depletion has motivated the intentional recharge of groundwater aquifers with excess surface water. Intentional groundwater recharge, also called managed aquifer recharge (MAR) has many benefits. It can increase groundwater storage, decrease land subsidence, mitigate flood risk, starve-off sea water intrusion, help regulate streamflow and stream temperature during dry seasons, and improve overall water security. This research will investigate the difference in groundwater quality between two MAR strategies that are used to introduce surface floodwaters into the groundwater system at two side-by-site locations in Central Valley California. Their findings will future implementation of intentional groundwater recharge strategies that improve groundwater quality for communities. Following the exceptionally wet year in California that recorded over 300% of its normal precipitation in snowpack and rainfall, resulting in widespread flooding, researchers will study the effect of using the floodwater to recharge aquifers, at two sites undergoing two different MAR strategies, on the quality of groundwater. The MAR strategies are drywells injection and surface flooding of farm fields. The researchers will investigate the occurrence, distribution, and changes in the concentrations of anthropogenic and geogenic contaminants such as nitrate, arsenic, uranium, chromium, other pesticides, and indicators of coliform bacteria. Investigators will quantify the release of contaminants to groundwater from each recharge strategy and assess the links between contaminant mobilization processes to hydrogeochemical conditions that affect the mobilization. The findings from this research will improve understanding of the effect of different managed aquifer recharge strategies and inform the future development of treatment and abatement options during the recharge process for future water management practices.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.