Groundwater Flow Dynamics at the Hubbard Brook Experimental Forest, NH (2018 – Current)
Advisers: Madeline Schreiber (VT), Kevin McGuire (VT), Scott Bailey (USFS)
Groundwater response to precipitation and snow melt events is an important mechanism for the generation of surface runoff. In this study we investigate the development of shallow water tables across three different hill-slope transects with the goal of quantifying subsurface hydrologic fluxes, temporal changes in groundwater flow direction, and water table peak lag-times between different hill-slope positions. The estimation of hydrologic fluxes will be used to support the over-arching project of investigating lateral weathering gradients in glaciated catchments.
Variations in Discharge and Chemistry of Cave Drips in Grand Caverns, VA (2015-Current)
Adviser: Daniel Doctor (USGS)
Caves are useful access points for the sampling and monitoring of vadose waters in karst terrains. The physical and chemical characteristics of drip waters can provide us with insight into the mechanisms controlling recharge to the underlying water table. In this study, we monitored two cave drips for changes in flow rate, major ion concentration, specific conductance, & stable isotope composition (δ2H , δ18O , & δ13C). We also monitored cave air CO2 concentration, measured soil moisture above the cave, and collected precipitation at the surface. Results showed a cool-season bias towards recharge waters when compared to the isotopic composition of meteoric waters collected above the cave. The two drip sites had markedly different flow rates and response to recharge events despite being located a short distance apart within the same chamber.
Dissolved Nutrient (Nitrogen and Carbon) Concentrations Across Land Use Gradients in Sinking Streams at Clover Hollow, VA (2018 – 2019)
Advisers: Wil Orndorff (DCR), Durelle Scott (VT)
An excess amount of dissolved nutrients (in the form of Nitrogen and Phosphorous) are the primary cause of eutrophication in surface water bodies such as rivers, lakes, and estuaries. We are currently investigating spatial and temporal changes in the concentration of total dissolved nitrogen and organic carbon in karst streams that cross significant gradients in land-use, elevation, and bedrock geology. We are then comparing nutrient loads in surface streams with those in the cave environment to observe any consumption or production of nutrients in the subsurface.