ANALYSIS OF TIME-SERIES MEASUREMENTS OF SEDIMENT TEMPERATURE FOR IDENTIFICATION OF GAINING VS LOSING PORTIONS OF JUDAY-CREEK, INDIANA

Identifying locations at which groundwater and surface water interact can be important in a variety of contexts including the development of water budgets, the determination of migration pathways for nutrients and contaminants, and the estimation of thermal budgets along small wa ter bodies. Some difficulty has been experienced in identifying locati ons of inflows over large regions when detailed groundwater informatio n is not known. A method is suggested herein for the identification of the location of inflows-outflows in both creeks and streams. This met hod, applied to a small creek in northern Indiana, involves measuremen t over time of both the sediment temperature and the temperature at th e base of the overlying water column. The results are used to define r eaches along the creek which are gaining and reaches along the creek w hich are losing. These results are supported by independent measuremen ts of groundwater elevations at several points along the stream. It is argued that this method provides an excellent screening tool for the identification of gaining and losing reaches of small waterways.