Investigating Groundwater Flow and Aquifer Recharge in a Karstic Aquifer Considering the Potentiometric Surface-A Research Prospectus

摘要

Surface-subsurface hydrologic interactions and groundwater flow in karstic terrain are poorly understood due to the spatial complexity of carbonate limestone influencing water bodies and soil-stored water. The goal of this study is to investigate therelationship between surface water and groundwater, specifically aquifer recharge, and better understand groundwater flow direction on the 12,000 ha Ichauway property managed by the Joseph W. Jones Ecological Research Center in Baker County, Georgia. Nested observational wells will be installed near streams and inside wetlands to investigate vertical and horizontal gradients. Odyssey water level capacitance dataloggers will measure fluctuations in the water table over time. A flow direction map of the residuum layer will be generated based on the surficial hydrologic data gathered from this study and previous studies on site. Groundwater flow direction will also be investigated by analyzing the potentiometric surface of the Upper Floridan Aquifer (UFA)generated by a USGS regional model of the Dougherty Plain. Household wells accessing the UFA will compliment the regional model to improve the resolution of the local domain. The successful completion of this project will improve understanding of subsurface hydrology in low sloping karstic terrain and could aid future best management practices on site by recognizing locations of hydrologic entry and exit. Furthermore, results will highlight the influence of regional groundwater irrigation on aquatic and terrestrial ecosystems in the Apalachicola River, Chattahoochee River, Flint River Basin by outlining the connected nature between surface water and groundwater in karstic areas. The large question of interest is that of ho w much pumping off-site canoccur before water levels on site drop to levels causing ecological damage.