Utilizing Resistivity Soundings and Forensic Geochemistry to Better Understand the Groundwater Contributions and the Interaction with Surface Water in a Streambed in the Texas Gulf Coast Area

Dynamic interactions between surface waters and adjacent aquifers can significantly affect the freshwater quality and quantity in a reservoir. Interactions between groundwater and surface water systems with transient hydraulic conditions, such as changes in groundwater discharge rates, are not well understood. Greater understanding of the groundwater-surface water transition zone is needed to better characterize the spatial and temporal extent of groundwater discharge and the associated impacts to coastal water resources. This study will be utilizing resistivity soundings in order to provide vertical profiles of groundwater seeps and provide a stratigraphic characterization of the bank and streambed transition boundaries. Isotope and other environmental tracers will be used to trace water sources within the transition zone and surface water and to evaluate the degree of mixing. This combination of data products will offer valuable information regarding the hydrogeology of coastal settings for freshwater resource management, sustainability and conservation of the Gulf Coast region of South Texas. The ultimate goal of this research is to find new methods that improve the speed and accuracy of an existing system or technique, or to find information that sheds light on some feature or phenomena that was not previously available. The combination of these methods provides valuable data that can be used to investigate land use/climate change impacts on water temperature, groundwater inflow and the forecasting of surface water availability. Improving our understanding of these water interactions can improve the management of water supplies including groundwater flow to coastal surface waters.