Groundwater Discharges, Nutrient Transport and Bluff Erosion in Lake Erie
We are spinning up a new Pennsylvania Sea Grant funded project to look at the role of groundwater in coastal erosion and nutrient transport in Lake Erie. We will install groundwater wells at the Lake Erie Grape Research and Extension Center to monitor groundwater levels and nutrient concentrations in the surficial aquifer. We will use the observational data to construct a numerical model to simulate groundwater flow and transport in the study area. The observational data and numerical model results will be used to estimate groundwater and nutrient fluxes being exported to Lake Erie, evaluate whether groundwater is a driver of bluff erosion, and develop curricula to meet new Science, Technology & Engineering, Environmental Literacy and Sustainability (STEELS) standards at local middle and high schools.
Ocean Surge-Driven Salinization of Delaware Inland Bays
Coastal communities around the world face an increasing risk from surge-driven inundation because of rising sea levels and intensifying storm conditions. During storm surges, inland propagation of ocean water drives infiltration of saltwater into the fresh groundwater, jeopardizing coastal water resources. The magnitude, shape, and duration of these ocean surges vary both between storm events and spatially during a given storm, resulting from differences in bathymetry, coastline shape, and the path and characteristics of the storm. This project used a coupled surface water-groundwater model (Hydrogeosphere) to study how these temporal and spatial variabilities in ocean surge affect groundwater salinization and recovery in the Delaware (DE) Inland Bays.
Feedbacks Between Land-use Changes, Subsidence and Hydrology in Karst Settings
InSAR analysis of the State College area has revealed that portions of the Blue & White Golf Courses are subsiding at rates of up to 4 cm/yr, substantially faster than the surrounding area. This project investigates how land use, changes in land management, and hydrologic variability interact with the underlying geology to drive this localized subsidence. Remote sensing observations are being combined with field-based geophysical surveys and hydrologic monitoring to characterize subsurface conditions, track changes in water movement, and identify potential mechanisms responsible for the observed deformation. By integrating measurements across multiple spatial and temporal scales, this work aims to better understand why the golf course is sinking so rapidly and how human activities and hydrologic change influence subsidence in karst landscapes
Effects of Sea-level Rise and Groundwater Pumping on Salinization in Coastal Aquifers
Water security has become a global concern as climate change progresses and rising populations increase stress on freshwater resources. Coastal communities face an additional level of risk of contamination from saltwater intrusion (SWI) driven by rising sea levels and groundwater pumping. In Dover, DE there is competition for groundwater from the surficial aquifer between the City of Dover and irrigating farmers. A field-based numerical model (SEAWAT), which includes included salinized marshland and tidal streams, along with irrigation and municipal pumping wells was applied to test various pumping reduction and redistribution approaches to determine the most effective SWI mitigation strategies.
Hydrology and Geochemistry of Shallow Wastewater Injection in a Coastal Carbonate Aquifer
Our research in Marathon, Florida, examines how treated wastewater injected into the highly permeable Key Largo Limestone aquifer moves and ultimately discharges into surrounding coastal waters. We collected carbonate cores from the Key Largo Limestone and established a network of groundwater monitoring wells near the Marathon wastewater treatment facility. The cores preserve sections of the aquifer that have experienced different salinity regimes and degrees of secondary porosity, providing material for mineralogical and geochemical analyses focused on how wastewater-derived phosphorus is stored within the carbonate aquifer. Monitoring wells have been instrumented with conductivity, temperature, and water-level sensors to track changes in groundwater flow and salinity over time. Together, the core and monitoring datasets provide a framework for linking aquifer geology and geochemistry with groundwater conditions and will allow us to evaluate how the system responds when shallow wastewater injection ends
Barrier Island Groundwater Dynamics
Nearly 1.5 million people inhabit barrier islands along the U.S. Atlantic and Gulf Coasts and coastal groundwater dynamics influence the availability of freshwater, ecosystem health, pollutant transport, and flooding in these densely populated communities. However, groundwater dynamics, including the aquifer head distribution and subsurface salinity structure, in coastal aquifers are affected by multiple environmental forcings, such as waves, tides, storm surges, and precipitation that act on a variety of spatial and temporal scales, making coastal groundwater dynamics complex and difficult to predict. In this project, we used 3-years of groundwater observations and community science data to:
Characterize ocean-aquifer-sound exchanges and the evolution of the upper saline plum during storms
Characterize the difference in the propagation of water table fluctuations driven by tides and ocean surges
Predict the timing and location of groundwater-driven flooding along the Outer Banks