Quantifying Ephemeral Streambed Infiltration from Downhole Temperature Measurements Collected Before and After Streamflow

Abstract

mentation in the streambed that could be removed by flood waters, or in-stream monitoring, which can present A constant flux infiltration experiment was conducted to determine significant safety concerns. Solute tracer tests generally the feasibility of using downhole temperature measurements to estiare labor intensive and costly because they require mate infiltration flux. Temperatures measured using a downhole chemical analyses and controlled addition of tracer soluthermistor within a 15.4-m-deep borehole compare well with temperatures measured with buried thermocouples in an adjacent borehole tions. As a result, there is a need for an alternative to 5 m depth. Numerical forward model simulations were conducted method to determine the infiltration rate beneath an using VS2DI. A numerical sensitivity analysis showed that the temperephemeral stream that does not rely on measurements ature profile was most sensitive to the average temperature of the made during streamflow. Furthermore, it would be adinfiltrating water, the infiltration flux, and the specific heat capacity vantageous if this method were applicable in deep vaof dry soil. The high sensitivity of these variables allows for a simple dose zones that commonly are associated with arid and sequential optimization to be used to estimate the average temperasemiarid environments and if measurements could be ture of the infiltrating water, the water flux, and the specific heat made in existing wells. capacity of dry soil from numerical inversion of temperature measure-The use of heat as a tracer to monitor subsurface ments. Downhole temperature measurements could be a useful comwater flow has been shown to be a promising alternative plement to shallow streambed temperature methods, allowing for better quantification of the contribution of streambed infiltration to to water content or water pressure monitoring and basin-scale recharge.

Water Flow Behavior and Storage Potential of the Semi-Arid Ephemeral River System in the Mara Basin of Kenya

“…These techniques can broadly be classified into three main clusters. The first cluster entails methods -such as monitoring fluctuations in water content, controlled infiltration experiments and use of heat as a tracer -to monitor infiltration through the river bed providing point estimates of infiltration and transmission losses (Parissopoulos and Wheater, 1992;Dunkerley and Brown, 1999;Stewart-deaker et al, 2000;Dahan et al, 2008;Dunkerley, 2008;Batlle-Aguilar and Cook, 2012;Dowman et al, 2013). Although measurements of water content allow for a rapid detection of vertical infiltration rates, it is not possible to determine flux changes once stream bed sediments are saturated.…”

“…Further, alteration of channel geometry makes it difficult to adequately parameterize over a long stretch of reaches for accurate simulation of key hydrological processes using existing models. The third group of approaches involves monitoring groundwater storage dynamics in the alluvium before, during and after flow events providing information on actual recharge into the alluvial deposits (Freyberg, 1983;Sorman and Abdulrazzak, 1993;Abdulrazzak and Sorman, 2006;Christiansen et al, 2011;Dowman et al, 2013). Application of groundwater mounding to estimate direct recharge in ERS relies on numerous assumptions, in particular, homogeneity in the porous medium and uniformity in the geological properties in the longitudinal direction (Hantush, 1967;Goodrich et al, 2013).…”

Estimating Surface Water Presence and Infiltration in Ephemeral to Intermittent Streams in the Southwestern US

“…However, stream channel recharge estimates in intermittent systems can be poorly constrained due to the scarcity of streamflow and stream water presence measurements. Methodologies used to assess intermittent stream infiltration and recharge in arid and semi-arid systems include geochemical studies, water balance approaches, in-situ infiltrometers, and thermal monitoring and modeling approaches (Besbes et al, 1978;Sorman and Abdulrazzak, 1993;Constantz et al, 2003;Dowman et al, 2003;Goodrich et al, 2004;Coes and Pool, 2005;Blasch et al, 2006;Baillie et al, 2007;Callegary et al, 2007). However, the temporal dynamics of intermittent streamflow, a major control on potential infiltration, remain to be explicitly quantified.…”

Rapid estimation of recharge potential in ephemeral-stream channels using electromagnetic methods, and measurements of channel and vegetation characteristics

“…Many methods for assessing recharge and RCP at both local and regional scales have been developed (Osterkamp et al, 1994;Dowman et al, 2003;Hevesi et al, 2003;Murray et al, 2003;Goodrich et al, 2004;Maurer et al, 2004;Scanlon, 2004). Traditional methods for improving recharge estimates, by drilling and instrumenting boreholes, and by monitoring streamflow, are expensive owing to the physical scale of many watersheds and urbanized areas.…”