Chris Barton (Committee Member), David Dominic (Committee Member), Robert Ritzi (Advisor)
Master of Science (MS)
The temperature of groundwater in aquifers is relatively stable when compared to the water temperature in surface-water bodies. However, in aquifers that are hydraulically connected to rivers that have water flux into the aquifer, the local aquifer temperature can show seasonal variation. This project focused on the thermally-altered, near-river zone of such an aquifer, and used numerical methods to examine the extent of seasonal variation in temperature into the aquifer, and the attenuation and phase shift of the signal with distance from the river. The results show that the extent of alteration by diffusive heat flow is negligible compared to the advective component of heat flow. Therefore, because heat transport is driven primarily by advection, the extent of seasonal variation in temperature into the aquifer, as well as the attenuation and phase lag of the signal are significantly dependent on the hydraulic gradient between the river and aquifer. Furthermore, the extent, attenuation, and phase lag of seasonal variation in temperature within the aquifer was found to be strongly dependent on heterogeneity. Considerable differences in the expression of the seasonally varying temperature signal were found to occur as a result of the local presence of high and/or low hydraulic conductivity material. Finally, for the Miami Valley aquifer (which the models used in this study were based upon), seasonal variation in groundwater temperature is expected only within a lateral distance of about 135 meters from the river and there only within a depth of about 25 meters.
Department or Program
Department of Earth and Environmental Sciences
Year Degree Awarded
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