An assessment of the tracer-based approach to quantifying groundwater contributions to streamflow Export

@article{citeulike:682236, abstract = {The use of conservative geochemical and isotopic tracers along with mass balance equations to determine the pre-event groundwater contributions to streamflow during a rainfall event is widely used for hydrograph separation; however, aspects related to the influence of surface and subsurface mixing processes on the estimates of the pre-event contribution remain poorly understood. Moreover, the lack of a precise definition of \&\#8220;pre-event\&\#8221; versus \&\#8220;event\&\#8221; contributions on the one hand and \&\#8220;old\&\#8221; versus \&\#8220;new\&\#8221; water components on the other hand has seemingly led to confusion within the hydrologic community about the role of Darcian-based groundwater flow during a storm event. In this work, a fully integrated surface and subsurface flow and solute transport model is used to analyze flow system dynamics during a storm event, concomitantly with advective-dispersive tracer transport, and to investigate the role of hydrodynamic mixing processes on the estimates of the pre-event component. A number of numerical experiments are presented, including an analysis of a controlled rainfall-runoff experiment, that compare the computed Darcian-based groundwater fluxes contributing to streamflow during a rainfall event with estimates of these contributions based on a tracer-based separation. It is shown that hydrodynamic mixing processes can dramatically influence estimates of the pre-event water contribution estimated by a tracer-based separation. Specifically, it is demonstrated that the actual amount of bulk flowing groundwater contributing to streamflow may be much smaller than the quantity indirectly estimated from a separation based on tracer mass balances, even if the mixing processes are weak.}, author = {Jones, J. P. and Sudicky, E. A. and Brookfield, A. E. and Park, Y. J.}, citeulike-article-id = {682236}, citeulike-linkout-0 = {http://www.agu.org/pubs/crossref/2006/2005WR004130.shtml}, citeulike-linkout-1 = {http://dx.doi.org/10.1029/2005WR004130}, comment = {We wrote a comment on this paper [1], the authors replied [2] we also published a reply (to the authors' reply) on my blog [3]. [1] http://www.citeulike.org/user/jprenaud/article/1696699 [2] http://www.citeulike.org/user/jprenaud/article/2425946 [3] http://www.jprenaud.info/2007/12/10/comment-on-sudicky-et-al-in-water-resources-research}, day = {18}, doi = {10.1029/2005WR004130}, journal = {Water Resources Research}, keywords = {hillslope, hydrology, inhm, old-new-water, processes, tracing, transport}, month = {February}, pages = {W02407+}, posted-at = {2007-08-20 11:16:48}, priority = {0}, title = {An assessment of the tracer-based approach to quantifying groundwater contributions to streamflow}, url = {http://dx.doi.org/10.1029/2005WR004130}, volume = {42}, year = {2006} }

TY - JOUR ID - citeulike:682236 L3 - citeulike-article-id:682236 N2 - The use of conservative geochemical and isotopic tracers along with mass balance equations to determine the pre-event groundwater contributions to streamflow during a rainfall event is widely used for hydrograph separation; however, aspects related to the influence of surface and subsurface mixing processes on the estimates of the pre-event contribution remain poorly understood. Moreover, the lack of a precise definition of “pre-event” versus “event” contributions on the one hand and “old” versus “new” water components on the other hand has seemingly led to confusion within the hydrologic community about the role of Darcian-based groundwater flow during a storm event. In this work, a fully integrated surface and subsurface flow and solute transport model is used to analyze flow system dynamics during a storm event, concomitantly with advective-dispersive tracer transport, and to investigate the role of hydrodynamic mixing processes on the estimates of the pre-event component. A number of numerical experiments are presented, including an analysis of a controlled rainfall-runoff experiment, that compare the computed Darcian-based groundwater fluxes contributing to streamflow during a rainfall event with estimates of these contributions based on a tracer-based separation. It is shown that hydrodynamic mixing processes can dramatically influence estimates of the pre-event water contribution estimated by a tracer-based separation. Specifically, it is demonstrated that the actual amount of bulk flowing groundwater contributing to streamflow may be much smaller than the quantity indirectly estimated from a separation based on tracer mass balances, even if the mixing processes are weak. JF - Water Resources Research TI - An assessment of the tracer-based approach to quantifying groundwater contributions to streamflow VL - 42 SP - W02407 KW - hillslope KW - hydrology KW - inhm KW - old-new-water KW - processes KW - tracing KW - transport N1 - We wrote a comment on this paper [1], the authors replied [2] we also published a reply (to the authors' reply) on my blog [3]. [1] http://www.citeulike.org/user/jprenaud/article/1696699 [2] http://www.citeulike.org/user/jprenaud/article/2425946 [3] http://www.jprenaud.info/2007/12/10/comment-on-sudicky-et-al-in-water-resources-research AU - Jones, JP AU - Sudicky, EA AU - Brookfield, AE AU - Park, YJ PY - 2006/02/18/ UR - http://dx.doi.org/10.1029/2005WR004130 ER -