Heat, Chloride, and Specific Conductance as Ground Water Tracers near Streams

Abstract

Commonly measured water quality parameters were compared to heat as tracers of stream water exchange with ground water. Temperature, specific conductance, and chloride were sampled at various frequencies in the stream and adjacent wells over a 2-year period. Strong seasonal variations in stream water were observed for temperature and specific conductance. In observation wells where the temperature response correlated to stream water, chloride and specific conductance values were similar to stream water values as well, indicating significant stream water exchange with ground water. At sites where ground water temperature fluctuations were negligible, chloride and/or specific conductance values did not correlate to stream water values, indicating that ground water was not significantly influenced by exchange with stream water. Best-fit simulation modeling was performed at two sites to derive temperature-based estimates of hydraulic conductivities of the alluvial sediments between the stream and wells. These estimates were used in solute transport simulations for a comparison of measured and simulated values for chloride and specific conductance. Simulation results showed that hydraulic conductivities vary seasonally and annually. This variability was a result of seasonal changes in temperature-dependent hydraulic conductivity and scouring or clogging of the streambed. Specific conductance fits were good, while chloride data were difficult to fit due to the infrequent (quarterly) stream water chloride measurements during the study period. Combined analyses of temperature, chloride, and specific conductance led to improved quantification of the spatial and temporal variability of stream water exchange with shallow ground water in an alluvial system.

Investigating the spatio-temporal variability in groundwater and surface water interactions: a multi-technique approach

“…Furthermore, by conducting the study on two rivers in the same catchment, controls on the gaining and losing behaviour of neighbouring rivers can be investigated. Studies that employ multiple techniques for such investigations have been historically less common than research focussed on one or two methods, and can provide additional and more robust information for groundwater-surface water studies (Cox et al, 2007).…”

Linking Spatial Patterns of Groundwater Table Dynamics and Streamflow Generation Processes in a Small Developed Catchment

“…While multi-method approaches have historically been less common, they can overcome the large uncertainties that are attributed to single method applications and provide additional and more robust information for example in groundwater-surface water interactions [3][4][5] to obtain unequivocal results [6]. Moreover, by combining methods in different compartments of the hydrological cycle or different scales within the catchment (plot-, reach-scale) long time series are not necessarily needed to understand catchment reaction or the contribution of runoff components during varying saturation conditions (floods or low flow) in small and meso-scale catchments [7][8][9][10].…”

Streambed exchanges along tributary streams in humid watersheds

“…Universally heterogeneity in streambed hydraulic conductivities leads to streambed exchanges in all three orientations, plan view [e.g., Conant, 2004], cross section, and longitudinal to stream [e.g., Becker et al, 2004;Essaid et al, 2006]. For significant hydraulic gradients, Su et al [2004] portrayed the influence of variable hydraulic conductivities on the complexity of streambed flow patterns, and Cox et al [2007] showed the impacts of gradual downstream changes in both hydraulic gradients and hydraulic conductivities on crosssection streambed exchange patterns. On a larger spatial scale, combined seasonal variability in near-stream and regional groundwater flow patterns combined with reach-specific streambed geomorphology has been shown to result in both spatial and temporal variability in streambed exchanges along tributary streams [e.g., Niswonger and Prudic, 2003;Stonestrom et al, 2007].…”