NSF Award
2500969
Hurricane Helene made landfall as a Category 4 storm on September 26, 2024, delivering 12-16 inches of rainfall and a 9-foot storm surge to Florida’s Gulf Coast karstic coastlines. During hurricanes, the combined effects of intense rainfall, storm surge, and flooding can enhance groundwater recharge and discharge, intensify aquifer salinization, mobilize contaminants, and deteriorate both groundwater and surface water quality. For example, sudden discharges of nutrient-rich groundwater following extreme precipitation events have been associated with phenomena like planktonic blooms and red tides. Although groundwater-surface water interactions and aquifer salinization in coastal areas are widely studied, most research were conducted during regular weather conditions, potentially underestimating the magnitude of extreme events on coastal aquifer dynamics. Therefore, this study aims to assess both the immediate and long-term effects of hurricanes on hydrogeology and nutrient geochemistry in karstic aquifers. The findings will inform coastal management strategies and improve hydrogeological model predictions, helping to mitigate hurricane-induced impacts on coastal ecosystems and water resources. This project will foster collaboration between two early-career researchers and actively involve undergraduate and graduate students, including those from underrepresented minorities, with results integrated into Texas A&M University at Galveston and Florida Atlantic University courses.<br/><br/>This project will employ interdisciplinary hydrological, geophysical, and geochemical methods to: (1) Evaluate the degree of aquifer salinization and its effects on nutrient speciation, and (2) Quantify groundwater discharge and nutrient fluxes. Electrical resistivity tomography (ERT) will be used to assess aquifer salinization, while radon-222 will be utilized to quantify groundwater discharge. Nutrients and major ion concentrations will be measured from groundwater and surface water samples, with analyses focused on how hydrochemical patterns affect nutrient speciation. The research will be conducted post-hurricane and during baseflow conditions, enabling an assessment of the hydrological disturbances caused by the hurricane on aquifer salinization, groundwater-surface water interactions, and nutrient geochemistry, as well as tracking their progression over time. Additionally, the project will build on previously collected post-storm data from Alabama and Texas, allowing for a comparative analysis of groundwater system responses across different aquifer types (porous and karstic) in the Gulf Coast. This is especially relevant, given that the region is among the most vulnerable in the U.S. to the impacts of extreme weather events and climate change.<br/><br/>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.
