Articles | Volume 26, issue 7
https://doi.org/10.5194/hess-26-1883-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/hess-26-1883-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
13 Apr 2022
Research article |
| 13 Apr 2022
| 13 Apr 2022
Spatiotemporal variations in water sources and mixing spots in a riparian zone
Guilherme E. H. Nogueira
CORRESPONDING AUTHOR
Department of Hydrogeology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
Christian Schmidt
Department of Aquatic Ecosystem Analysis, Helmholtz Centre for Environmental Research – UFZ, Magdeburg, Germany
Daniel Partington
National Centre for Groundwater Research and Training, College of Science and Engineering, Flinders University, Adelaide, Australia
Philip Brunner
Centre for Hydrogeology and Geothermics, University of Neuchâtel, Neuchâtel, Switzerland
Jan H. Fleckenstein
CORRESPONDING AUTHOR
Department of Hydrogeology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
Bayreuth Centre of Ecology and Environmental Research, University of Bayreuth, Bayreuth, Germany
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Carolin Winter, Tam V. Nguyen, Andreas Musolff, Stefanie R. Lutz, Michael Rode, Rohini Kumar, and Jan H. Fleckenstein
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Thomas Hermans, Pascal Goderniaux, Damien Jougnot, Jan H. Fleckenstein, Philip Brunner, Frédéric Nguyen, Niklas Linde, Johan Alexander Huisman, Olivier Bour, Jorge Lopez Alvis, Richard Hoffmann, Andrea Palacios, Anne-Karin Cooke, Álvaro Pardo-Álvarez, Lara Blazevic, Behzad Pouladi, Peleg Haruzi, Alejandro Fernandez Visentini, Guilherme E. H. Nogueira, Joel Tirado-Conde, Majken C. Looms, Meruyert Kenshilikova, Philippe Davy, and Tanguy Le Borgne
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Benedikt J. Werner, Oliver J. Lechtenfeld, Andreas Musolff, Gerrit H. de Rooij, Jie Yang, Ralf Gründling, Ulrike Werban, and Jan H. Fleckenstein
Hydrol. Earth Syst. Sci., 25, 6067–6086, https://doi.org/10.5194/hess-25-6067-2021, https://doi.org/10.5194/hess-25-6067-2021, 2021
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Katharina Blaurock, Burkhard Beudert, Benjamin S. Gilfedder, Jan H. Fleckenstein, Stefan Peiffer, and Luisa Hopp
Hydrol. Earth Syst. Sci., 25, 5133–5151, https://doi.org/10.5194/hess-25-5133-2021, https://doi.org/10.5194/hess-25-5133-2021, 2021
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Dissolved organic carbon (DOC) is an important part of the global carbon cycle with regards to carbon storage, greenhouse gas emissions and drinking water treatment. In this study, we compared DOC export of a small, forested catchment during precipitation events after dry and wet preconditions. We found that the DOC export from areas that are usually important for DOC export was inhibited after long drought periods.
Karina Y. Gutierrez-Jurado, Daniel Partington, and Margaret Shanafield
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Understanding the hydrologic cycle in semi-arid landscapes includes knowing the physical processes that govern where and why rivers flow and dry within a given catchment. To gain this understanding, we put together a conceptual model of what processes we think are important and then tested that model with numerical analysis. The results broadly confirmed our hypothesis that there are three distinct regions in our study catchment that contribute to streamflow generation in quite different ways.
K. Koutantou, G. Mazzotti, and P. Brunner
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIII-B3-2021, 477–484, https://doi.org/10.5194/isprs-archives-XLIII-B3-2021-477-2021, https://doi.org/10.5194/isprs-archives-XLIII-B3-2021-477-2021, 2021
Cited articles
Appelo, C. A. J. and Postma, D.: Geochemistry, Groundwater and Pollution –
2nd Edn., A. A. Balkema Publishers, Amsterdam, 2005.
Aquanty Inc.: HydroGeoSphere Reference Manual, Waterloo,
https://www.aquanty.com/hgs-download (last access: 2 December 2021), 2015.
Battin, T. J.: Hydrologic flow paths control dissolved organic carbon fluxes
and metabolism in an alpine stream hyporheic zone, Water Resour. Res., 35, 3159–3169, 1999.
Bear, J. and Verruijt, A.: Modeling Groundwater Flow and Pollution, 1st Edn.,
edited by: Bear, J., D. Reidel Publishing Company, Dordrecht, ISBN 13:97S-1-5560S-015-9, https://doi.org/10.1007/978-94-009-3379-8, 1987.
Berezowski, T., Partington, D., Chormañski, J., and Batelaan, O.:
Spatiotemporal Dynamics of the Active Perirheic Zone in a Natural Wetland
Floodplain, Water Resour. Res., 55, 9544–9562, https://doi.org/10.1029/2019WR024777, 2019.
Bernhardt, E. S., Blaszczak, J. R., Ficken, C. D., Fork, M. L., Kaiser, K. E., and Seybold, E. C.: Control Points in Ecosystems: Moving Beyond the Hot
Spot Hot Moment Concept, Ecosystems, 20, 665–682, https://doi.org/10.1007/s10021-016-0103-y, 2017.
Biehler, A., Chaillou, G., Buffin-Bélanger, T., and Baudron, P.:
Hydrological connectivity in the aquifer–river continuum: Impact of river
stages on the geochemistry of groundwater floodplains, J. Hydrol., 590,
125379, https://doi.org/10.1016/j.jhydrol.2020.125379, 2020.
Boano, F., Demaria, A., Revelli, R., and Ridolfi, L.: Biogeochemical zonation
due to intrameander hyporheic flow, Water Resour. Res., 46, 1–13,
https://doi.org/10.1029/2008WR007583, 2010.
Boulton, A. J., Findlay, S., Marmonier, P., Stanley, E. H., and Valett, H. M.: The Functional Significance of the Hyporheic Zone in Streams and Rivers,
Annu. Rev. Ecol. Syst., 29, 59–81, https://doi.org/10.1146/annurev.ecolsys.29.1.59,
1998.
Broecker, T., Sobhi Gollo, V., Fox, A., Lewandowski, J., Nützmann, G.,
Arnon, S., and Hinkelmann, R.: High-Resolution Integrated Transport Model for
Studying Surface Water–Groundwater Interaction, Groundwater, 59, 488–502,
https://doi.org/10.1111/gwat.13071, 2021.
Buffington, J. M. and Tonina, D.: Hyporheic exchange in mountain rivers II: Effects of channel morphology on mechanics, scales, and rates of exchange, Geogr. Compass, 3, 1038–1062, https://doi.org/10.1111/j.1749-8198.2009.00225.x, 2009.
Cardenas, M. B.: Stream-aquifer interactions and hyporheic exchange in gaining and losing sinuous streams, Water Resour. Res., 45, 1–13,
https://doi.org/10.1029/2008WR007651, 2009.
Cirpka, O. A. and Kitanidis, P. K.: Characterization of mixing and dilution
in heterogeneous aquifers by means of local temporal moments, Water Resour.
Res., 36, 1221–1236, https://doi.org/10.1029/1999WR900354, 2000.
Delsman, J. R., Essink, G. H. P. O., Beven, K. J., and Stuyfzand, P. J.:
Uncertainty estimation of end-member mixing using generalized likelihood
uncertainty estimation (GLUE), applied in a lowland catchment, Water Resour.
Res., 49, 4792–4806, https://doi.org/10.1002/wrcr.20341, 2013.
Dentz, M., Le Borgne, T., Englert, A., and Bijeljic, B.: Mixing, spreading
and reaction in heterogeneous media: A brief review, J. Contam. Hydrol., 120–121, 1–17, https://doi.org/10.1016/j.jconhyd.2010.05.002, 2011.
Doherty, J.: PEST: Model-independent parameter estimation, User Manual, Watermark Numerical Computing, 368 pp., https://pesthomepage.org/documentation (last access: 26 May 2020), 2018.
Ebeling, P., Dupas, R., Abbott, B., Kumar, R., Ehrhardt, S., Fleckenstein,
J. H., and Musolff, A.: Long-Term Nitrate Trajectories Vary by Season in Western European Catchments, Global Biogeochem. Cy., 35, 1–19,
https://doi.org/10.1029/2021GB007050, 2021.
Fleckenstein, J. H., Niswonger, R. G., and Fogg, G. E.: River-aquifer
interactions, geologic heterogeneity, and low-flow management, Groundwater,
44, 837–852, https://doi.org/10.1111/j.1745-6584.2006.00190.x, 2006.
Flipo, N., Mouhri, A., Labarthe, B., Biancamaria, S., Rivière, A., and
Weill, P.: Continental hydrosystem modelling: The concept of nested
stream–aquifer interfaces, Hydrol. Earth Syst. Sci., 18, 3121–3149,
https://doi.org/10.5194/hess-18-3121-2014, 2014.
Frei, S., Knorr, K. H., Peiffer, S., and Fleckenstein, J. H.: Surface micro-topography causes hot spots of biogeochemical activity in wetland systems: A virtual modeling experiment, J. Geophys. Res.-Biogeo., 117, 1–18, https://doi.org/10.1029/2012JG002012, 2012.
Gassen, N., Griebler, C., Werban, U., Trauth, N., and Stumpp, C.: High
Resolution Monitoring Above and Below the Groundwater Table Uncovers Small-Scale Hydrochemical Gradients, Environ. Sci. Technol., 51, 13806–13815, https://doi.org/10.1021/acs.est.7b03087, 2017.
Gianni, G., Doherty, J., and Brunner, P.: Conceptualization and Calibration
of Anisotropic Alluvial Systems: Pitfalls and Biases, Groundwater, 57,
409–419, https://doi.org/10.1111/gwat.12802, 2019.
Gomez-Velez, J. D., Wilson, J. L., Cardenas, M. B., and Harvey, J. W.: Flow
and Residence Times of Dynamic River Bank Storage and Sinuosity-Driven
Hyporheic Exchange, Water Resour. Res., 53, 8572–8595,
https://doi.org/10.1002/2017WR021362, 2017.
Gooseff, M. N.: Defining hyporheic zones - advancing our conceptual and
operational definitions of where stream water and groundwater meet, Geogr.
Compass, 4, 945–955, https://doi.org/10.1111/j.1749-8198.2010.00364.x, 2010.
Gu, C., Anderson, W., and Maggi, F.: Riparian biogeochemical hot moments
induced by stream fluctuations, Water Resour. Res., 48, 1–17,
https://doi.org/10.1029/2011WR011720, 2012.
Gupta, H. V., Kling, H., Yilmaz, K. K., and Martinez, G. F.: Decomposition of
the mean squared error and NSE performance criteria: Implications for
improving hydrological modelling, J. Hydrol., 377, 80–91,
https://doi.org/10.1016/j.jhydrol.2009.08.003, 2009.
Gutiérrez-Jurado, K. Y., Partington, D., Batelaan, O., Cook, P., and
Shanafield, M.: What Triggers Streamflow for Intermittent Rivers and Ephemeral Streams in Low-Gradient Catchments in Mediterranean Climates, Water Resour. Res., 55, 9926–9946, https://doi.org/10.1029/2019WR025041, 2019.
Hester, E. T., Young, K. I., and Widdowson, M. A.: Mixing of surface and
groundwater induced by riverbed dunes: Implications for hyporheic zone
definitions and pollutant reactions, Water Resour. Res., 49, 5221–5237,
https://doi.org/10.1002/wrcr.20399, 2013.
Hester, E. T., Young, K. I., and Widdowson, M. A.: Controls on mixing-dependent denitrification in hyporheic zones induced by riverbed
dunes: A steady state modeling study, Water Resour. Res., 50, 9048–9066, https://doi.org/10.1002/2014WR015424, 2014.
Hester, E. T., Cardenas, M. B., Haggerty, R., and Apte, S. V.: The importance
and challenge of hyporheic mixing, Water Resour. Res., 53, 3565–3575,
https://doi.org/10.1002/2016WR020005, 2017.
Hester, E. T., Eastes, L. A., and Widdowson, M. A.: Effect of Surface Water
Stage Fluctuation on Mixing-Dependent Hyporheic Denitrification in Riverbed
Dunes, Water Resour. Res., 55, 4668–4687, https://doi.org/10.1029/2018WR024198, 2019.
Hill, A. R.: Nitrate Removal in Stream Riparian Zones, J. Environ. Qual., 25, 743–755, https://doi.org/10.2134/jeq1996.00472425002500040014x, 1996.
Jencso, K. G., McGlynn, B. L., Gooseff, M. N., Bencala, K. E., and Wondzell,
S. M.: Hillslope hydrologic connectivity controls riparian groundwater turnover: Implications of catchment structure for riparian buffering and stream water sources, Water Resour. Res., 46, 1–18, https://doi.org/10.1029/2009WR008818, 2010.
Jones, C. N., Scott, D. T., Edwards, B. L., and Keim, R. F.: Perirheic mixing
and biogeochemical processing in flow-through and backwater floodplain
wetlands, Water Resour. Res., 50, 7394–7405, https://doi.org/10.1002/2014WR015647, 2014.
Jones, K. L., Poole, G. C., Woessner, W. W., Vitale, M. V., Boer, B. R.,
O'Daniel, S. J., Thomas, S. A., and Geffen, B. A.: Geomorphology, hydrology,
and aquatic vegetation drive seasonal hyporheic flow patterns across a
gravel-dominated floodplain, Hydrol. Process., 22, 2105–2113, https://doi.org/10.1002/hyp.6810, 2008.
Karan, S., Engesgaard, P., Looms, M. C., Laier, T., and Kazmierczak, J.:
Groundwater flow and mixing in a wetland-stream system: Field study and
numerical modeling, J. Hydrol., 488, 73–83, https://doi.org/10.1016/j.jhydrol.2013.02.030, 2013.
Kitanidis, K.: The concept of the dilution index, Water Resour. Res., 30, 2011–2026, https://doi.org/10.1029/94WR00762, 1994.
Knoben, W. J. M., Freer, J. E., and Woods, R. A.: Technical note: Inherent benchmark or not? Comparing Nash–Sutcliffe and Kling–Gupta efficiency scores, Hydrol. Earth Syst. Sci., 23, 4323–4331, https://doi.org/10.5194/hess-23-4323-2019, 2019.
Kolbe, T., de Dreuzy, J.-R., Abbott, B. W., Aquilina, L., Babey, T., Green, C. T., Fleckenstein, J. H., Labasque, T., Laverman, A. M., Marçais, J.,
Peiffer, S., Thomas, Z., and Pinay, G.: Stratification of reactivity determines nitrate removal in groundwater, P. Natl. Acad. Sci. USA, 116,
2494–2499, https://doi.org/10.1073/pnas.1816892116, 2019.
Kollet, S. J. and Maxwell, R. M.: Integrated surface-groundwater flow modeling: A free-surface overland flow boundary condition in a parallel
groundwater flow model, Adv. Water Resour., 29, 945–958,
https://doi.org/10.1016/j.advwatres.2005.08.006, 2006.
Lawrence, J. E., Skold, M. E., Hussain, F. A., Silverman, D. R., Resh, V.
H., Sedlak, D. L., Luthy, R. G., and McCray, J. E.: Hyporheic zone in urban
streams: A review and opportunities for enhancing water quality and improving aquatic habitat by active management, Environ. Eng. Sci., 30, 480–501, https://doi.org/10.1089/ees.2012.0235, 2013.
Lessels, J. S., Tetzlaff, D., Birkel, C., Dick, J., and Soulsby, C.: Water
sources and mixing in riparian wetlands revealed by tracers and geospatial
analysis, Water Resour. Res., 52, 456–470, https://doi.org/10.1002/2015WR017519, 2016.
Liggett, J. E., Partington, D., Frei, S., Werner, A. D., Simmons, C. T., and
Fleckenstein, J. H.: An exploration of coupled surface-subsurface solute
transport in a fully integrated catchment model, J. Hydrol., 529, 969–979,
https://doi.org/10.1016/j.jhydrol.2015.09.006, 2015.
Liu, S. and Chui, T. F. M.: Impacts of different rainfall patterns on
hyporheic zone under transient conditions, J. Hydrol., 561, 598–608,
https://doi.org/10.1016/j.jhydrol.2018.04.019, 2018.
Lutz, S. R., Trauth, N., Musolff, A., Van Breukelen, B. M., Knöller, K.,
and Fleckenstein, J. H.: How Important is Denitrification in Riparian Zones?
Combining End-Member Mixing and Isotope Modeling to Quantify Nitrate Removal
from Riparian Groundwater, Water Resour. Res., 56, e2019WR025528, https://doi.org/10.1029/2019WR025528, 2020.
Magliozzi, C., Grabowski, R. C., Packman, A. I., and Krause, S.: Toward a
conceptual framework of hyporheic exchange across spatial scales, Hydrol.
Earth Syst. Sci., 22, 6163–6185, https://doi.org/10.5194/hess-22-6163-2018, 2018.
Mayer, P. M., Reynolds, S. K., and Canfield, T. J.: Riparian buffer width,
vegetative cover, and nitrogen removal effectiveness: a review of current
science and regulations, Epa/600/R-05/118, 1–40, http://nepis.epa.gov/Exe/ZyPDF.cgi/2000O182.PDF?Dockey=2000O182.PDF (last access: 20 August 2021), 2006.
McCallum, J. L., Cook, P. G., Brunner, P., and Berhane, D.: Solute dynamics
during bank storage flows and implications for chemical base flow separation, Water Resour. Res., 46, 1–11, https://doi.org/10.1029/2009WR008539, 2010.
McClain, M. E., Boyer, E. W., Dent, C. L., Gergel, S. E., Grimm, N. B., Groffman, P. M., Hart, S. C., Harvey, J. W., Johnston, C. A., Mayorga, E.,
McDowell, W. H., and Pinay, G.: Biogeochemical Hot Spots and Hot Moments at
the Interface of Terrestrial and Aquatic Ecosystems, Ecosystems, 6, 301–312, https://doi.org/10.1007/s10021-003-0161-9, 2003.
Mertes, L. A. K.: Documentation and significance of the perirheic zone on
inundated floodplains, Water Resour. Res., 33, 1749–1762, https://doi.org/10.1029/97WR00658, 1997.
Mirus, B. B., Ebel, B. A., Heppner, C. S., and Loague, K.: Assessing the
detail needed to capture rainfall-runoff dynamics with physics-based hydrologic response simulation, Water Resour. Res., 47, 1–18,
https://doi.org/10.1029/2010WR009906, 2011.
Newcomer, M. E., Hubbard, S. S., Fleckenstein, J. H., Maier, U., Schmidt, C.,
Thullner, M., Ulrich, C., Flipo, N., and Rubin, Y.: Influence of Hydrological
Perturbations and Riverbed Sediment Characteristics on Hyporheic Zone
Respiration of CO2 and N2, J. Geophys. Res.-Biogeo., 123, 902–922, https://doi.org/10.1002/2017JG004090, 2018.
Nogueira, G. E. H., Schmidt, C., Trauth, N., and Fleckenstein, J. H.: Seasonal and short-term controls of riparian oxygen dynamics and the implications for redox processes, Hydrol. Process., 35, e14055, https://doi.org/10.1002/hyp.14055, 2021a.
Nogueira, G. E. H., Schmidt, C., Brunner, P., Graeber, D., and Fleckenstein,
J. H.: Transit-time and temperature control the spatial patterns of aerobic
respiration and denitrification in the riparian zone, Water Resour. Res., 57, e2021WR030117, https://doi.org/10.1029/2021WR030117, 2021b.
Nogueira, G. E. H., Schmidt, C., Partington, D., Brunner, P., and Fleckenstein, J. H.: Spatio-temporal variations of water sources and mixing spots in a riparian zone: supplementary data, HydroShare [data set], https://doi.org/10.4211/hs.a0dc51142fe249f89877c4005e0b6947, 2022.
Ocampo, C. J., Oldham, C. E., and Sivapalan, M.: Nitrate attenuation in
agricultural catchments: Shifting balances between transport and reaction,
Water Resour. Res., 42, 1–16, https://doi.org/10.1029/2004WR003773, 2006.
Ong, C. G., Tanji, K. K., Dahlgren, R. A., Smith, G. R., and Quek, A. F.:
Water Quality and Trace Element Evapoconcentration in Evaporation Ponds for
Agricultural Waste Water Disposal, J. Agric. Food Chem., 43, 1941–1947,
https://doi.org/10.1021/jf00055a034, 1995.
Partington, D., Brunner, P., Simmons, C. T., Therrien, R., Werner, A. D.,
Dandy, G. C., and Maier, H. R.: A hydraulic mixing-cell method to quantify the groundwater component of streamflow within spatially distributed fully
integrated surface water-groundwater flow models, Environ. Model. Softw., 26, 886–898, https://doi.org/10.1016/j.envsoft.2011.02.007, 2011.
Partington, D., Brunner, P., Simmons, C. T., Werner, A. D., Therrien, R., Maier, H. R., and Dandy, G. C.: Evaluation of outputs from automated baseflow
separation methods against simulated baseflow from a physically based, surface water-groundwater flow model, J. Hydrol., 458–459, 28–39,
https://doi.org/10.1016/j.jhydrol.2012.06.029, 2012.
Partington, D., Brunner, P., Frei, S., Simmons, C. T., Werner, A. D.,
Therrien, R., Maier, H. R., Dandy, G. C. and Fleckenstein, J. H.: Interpreting streamflow generation mechanisms from integrated surface-subsurface flow models of a riparian wetland and catchment, Water
Resour. Res., 49, 5501–5519, https://doi.org/10.1002/wrcr.20405, 2013.
Partington, D., Knowling, M. J., Simmons, C. T., Cook, P. G., Xie, Y., Iwanaga, T., and Bouchez, C.: Worth of hydraulic and water chemistry observation data in terms of the reliability of surface water-groundwater exchange flux predictions under varied flow conditions, J. Hydrol., 590, 125441, https://doi.org/10.1016/j.jhydrol.2020.125441, 2020.
Pinay, G., Ruffinoni, C., Wondzell, S., and Gazelle, F.: Change in groundwater nitrate concentration in a large river floodplain: Denitrification, uptake, or mixing?, J. N. Am. Benthol. Soc., 17, 179–189, https://doi.org/10.2307/1467961, 1998.
Pinay, G., Peiffer, S., De Dreuzy, J., Krause, S., Hannah, D. M., Fleckenstein, J. H., Sebilo, M., Bishop, K., and Hubert-moy, L.: Upscaling
Nitrogen Removal Capacity from Local Hotspots to Low Stream Orders' Drainage Basins, Ecosystems, 18, 1101–1120, https://doi.org/10.1007/s10021-015-9878-5, 2015.
Poole, G. C., O'Daniel, S. J., Jones, K. L., Woessner, W. W., Bernhardt, E.
S., Helton, A. M., Stanford, J. A., Boer, B. R., and Beechie, T. J.:
Hydrologic spiralling: the role of multiple interactive flow paths in stream
ecosystems, River Res. Appl., 24, 1018–1031, https://doi.org/10.1002/rra.1099, 2008.
Pryshlak, T. T., Sawyer, A. H., Stonedahl, S. H., and Soltanian, M. R.:
Multiscale hyporheic exchange through strongly heterogeneous sediments, Water Resour. Res., 51, 9127–9140, https://doi.org/10.1002/2015WR017293, 2015.
Ranalli, A. J. and Macalady, D. L.: The importance of the riparian zone and
in-stream processes in nitrate attenuation in undisturbed and agricultural
watersheds – A review of the scientific literature, J. Hydrol., 389, 406–415, https://doi.org/10.1016/j.jhydrol.2010.05.045, 2010.
Rivett, M. O., Buss, S. R., Morgan, P., Smith, J. W. N., and Bemment, C. D.: Nitrate attenuation in groundwater: A review of biogeochemical controlling
processes, Water Res., 42, 4215–4232, https://doi.org/10.1016/j.watres.2008.07.020, 2008.
Savoy, H., Kalbacher, T., Dietrich, P., and Rubin, Y.: Geological heterogeneity: Goal-oriented simplification of structure and characterization needs, Adv. Water Resour., 109, 1–13, https://doi.org/10.1016/j.advwatres.2017.08.017, 2017.
Sawyer, A. H.: Enhanced removal of groundwater-borne nitrate in heterogeneous aquatic sediments, Geophys. Res. Lett., 42, 403–410, https://doi.org/10.1002/2014GL062234, 2015.
Sawyer, A. H. and Cardenas, M. B.: Hyporheic flow and residence time
distributions in heterogeneous cross-bedded sediment, Water Resour. Res., 45, 1–12, https://doi.org/10.1029/2008WR007632, 2009.
Sawyer, A. H., Cardenas, M. B., Bomar, A., and Mackey, M.: Impact of dam
operations on hyporheic exchange in the riparian zone of a regulated river,
Hydrol. Process., 23, 2129–2137, https://doi.org/10.1002/hyp.7324, 2009.
Sawyer, A. H., Kaplan, L. A., Lazareva, O., and Michael, H. A.: Hydrologic
dynamics and geochemical responses within a floodplain aquifer and hyporheic
zone during Hurricane Sandy, Water Resour. Res., 50, 4877–4892,
https://doi.org/10.1002/2013WR015101, 2014.
Schilling, O. S., Gerber, C., Partington, D. J., Purtschert, R., Brennwald,
M. S., Kipfer, R., Hunkeler, D., and Brunner, P.: Advancing Physically-Based
Flow Simulations of Alluvial Systems Through Atmospheric Noble Gases and the
Novel37Ar Tracer Method, Water Resour. Res., 53, 10465–10490,
https://doi.org/10.1002/2017WR020754, 2017.
Schilling, O. S., Cook, P. G., and Brunner, P.: Beyond Classical Observations
in Hydrogeology: The Advantages of Including Exchange Flux, Temperature,
Tracer Concentration, Residence Time, and Soil Moisture Observations in
Groundwater Model Calibration, Rev. Geophys., 57, 146–182,
https://doi.org/10.1029/2018RG000619, 2019.
Schmadel, N. M., Ward, A. S., Kurz, M. J., Fleckenstein, J. H., Zarnetske, J. P., Hannah, D. M., Blume, T., Vieweg, M., Blaen, P. J., Schmidt, C., Knapp, J. L. A., Klaar, M. J., Romeijn, P., Datry, T., Keller, T., Folegot, S., Arricibita, A. I. M., and Krause, S.: Stream solute tracer timescales changing with discharge and reach length confound process interpretation, Water Resour. Res., 52, 3227–3245, https://doi.org/10.1002/2015WR018062, 2016.
Schneider, P., Vogt, T., Schirmer, M., Doetsch, J., Linde, N., Pasquale, N.,
Perona, P., and Cirpka, O. A.: Towards improved instrumentation for assessing
river-groundwater interactions in a restored river corridor, Hydrol. Earth
Syst. Sci., 15, 2531–2549, https://doi.org/10.5194/hess-15-2531-2011, 2011.
Song, X., Chen, X., Stegen, J., Hammond, G., Song, H., Dai, H., Graham, E.,
and Zachara, J. M.: Drought Conditions Maximize the Impact of High-Frequency
Flow Variations on Thermal Regimes and Biogeochemical Function in the
Hyporheic Zone, Water Resour. Res., 54, 7361–7382, https://doi.org/10.1029/2018WR022586, 2018.
Stegen, J. C., Fredrickson, J. K., Wilkins, M. J., Konopka, A. E., Nelson,
W. C., Arntzen, E. V., Chrisler, W. B., Chu, R. K., Danczak, R. E., Fansler,
S. J., Kennedy, D. W., Resch, C. T., and Tfaily, M.: Groundwater-surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover, Nat. Commun., 7, 11237, https://doi.org/10.1038/ncomms11237, 2016.
Stigter, T. Y., Van Ooijen, S. P. J., Post, V. E. A., Appelo, C. A. J., and
Carvalho Dill, A. M. M.: A hydrogeological and hydrochemical explanation of
the groundwater composition under irrigated land in a Mediterranean environment, Algarve, Portugal, J. Hydrol., 208, 262–279,
https://doi.org/10.1016/S0022-1694(98)00168-1, 1998.
Sun, X., Bernard-Jannin, L., Sauvage, S., Garneau, C., Arnold, J. G.,
Srinivasan, R., and Sánchez-Pérez, J. M.: Assessment of the
denitrification process in alluvial wetlands at floodplain scale using the
SWAT model, Ecol. Eng. 103, 344–358, https://doi.org/10.1016/j.ecoleng.2016.06.098, 2017.
Tang, Q., Kurtz, W., Schilling, O. S., Brunner, P., Vereecken, H., and
Hendricks Franssen, H. J.: The influence of riverbed heterogeneity patterns
on river-aquifer exchange fluxes under different connection regimes, J. Hydrol., 554, 383–396, https://doi.org/10.1016/j.jhydrol.2017.09.031, 2017.
Therrien, R., McLaren, R. G., Sudicky, E. A., and Panday, S. M. : HydroGeoSphere, A three-dimensional numerical model describing fully-integrated subsurface and surface flow and solute transport, Groundwater Simulations Group, p. 426, https://www.ggl.ulaval.ca/fileadmin/ggl/documents/rtherrien/hydrogeosphere.pdf (last access: 29 November 2021), 2010.
Tóth, J.: A theoretical analysis of groundwater flow in small drainage basins, J. Geophys. Res., 68, 4795–4812, https://doi.org/10.1029/JZ068i016p04795, 1963.
Trauth, N. and Fleckenstein, J. H.: Single discharge events increase reactive efficiency of the hyporheic zone, Water Resour. Res., 53, 779–798, https://doi.org/10.1111/j.1752-1688.1969.tb04897.x, 2017.
Trauth, N., Schmidt, C., Maier, U., Vieweg, M., and Fleckenstein, J. H.:
Coupled 3-D stream flow and hyporheic flow model under varying stream and
ambient groundwater flow conditions in a pool-riffle system, Water Resour.
Res., 49, 5834–5850, https://doi.org/10.1002/wrcr.20442, 2013.
Trauth, N., Schmidt, C., Vieweg, M., Maier, U., and Fleckenstein, J. H.:
Hyporheic transport and biogeochemical reactions in pool-riffle systems under varying ambient groundwater flow conditions, J. Geophys. Res.-Biogeo., 119, 910–928, https://doi.org/10.1002/2013JG002586, 2014.
Trauth, N., Schmidt, C., Vieweg, M., Oswald, S. E., and Fleckenstein, J. H.:
Hydraulic controls of in-stream gravel bar hyporheic exchange and reactions,
Water Resour. Res., 51, 2243–2263, https://doi.org/10.1002/2014WR015857, 2015.
Trauth, N., Musolff, A., Knöller, K., Kaden, U. S., Keller, T., Werban,
U., and Fleckenstein, J. H.: River water infiltration enhances denitrification efficiency in riparian groundwater, Water Res., 130, 185–199, https://doi.org/10.1016/j.watres.2017.11.058, 2018.
Triska, F. J., Kennedy, V. C., Avanzino, R. J., Zellweger, G. W., and Bencala, K. E.: Retention and transport of nutrients in a third-order stream: channel processes, Ecology, 70, 1877–1892, https://doi.org/10.2307/1938119, 1989.
Vidon, P., Allan, C., Burns, D., Duval, T. P., Gurwick, N., Inamdar, S., Lowrance, R., Okay, J., Scott, D., and Sebestyen, S.: Hot spots and hot moments in riparian zones: Potential for improved water quality management, J. Am. Water Resour. Assoc., 46, 278–298, https://doi.org/10.1111/j.1752-1688.2010.00420.x, 2010.
Vidon, P. G. F. and Hill, A. R.: Landscape controls on nitrate removal in
stream riparian zones, Water Resour. Res., 40, 1–14, https://doi.org/10.1029/2003WR002473, 2004.
Widdowson, M. A., Molz, F. J., and Benefield, L. D.: A numerical transport
model for oxygen- and nitrate-based respiration linked to substrate and
nutrient availability in porous media, Water Resour. Res., 24, 1553–1565, https://doi.org/10.1029/WR024i009p01553, 1988.
Wollschläger, U., Attinger, S., Borchardt, D., Brauns, M., Cuntz, M.,
Dietrich, P., Fleckenstein, J. H., Friese, K., Friesen, J., Harpke, A., Hildebrandt, A., Jäckel, G., Kamjunke, N., Knöller, K., Kögler, S., Kolditz, O., Krieg, R., Kumar, R., Lausch, A., Liess, M., Marx, A., Merz, R., Mueller, C., Musolff, A., Norf, H., Oswald, S. E., Rebmann, C., Reinstorf, F., Rode, M., Rink, K., Rinke, K., Samaniego, L., Vieweg, M., Vogel, H.-J., Weitere, M., Werban, U., Zink, M., and Zacharias, S.: The Bode
hydrological observatory: a platform for integrated, interdisciplinary
hydro-ecological research within the TERENO Harz/Central German Lowland
Observatory, Environ. Earth Sci., 76, 29, https://doi.org/10.1007/s12665-016-6327-5,
2017.
Wondzell, S. M.: The role of the hyporheic zone across stream networks, Hydrol. Process., 25, 3525–3532, https://doi.org/10.1002/hyp.8119, 2011.
Zarnetske, J. P., Haggerty, R., Wondzell, S. M., and Baker, M. A.: Dynamics
of nitrate production and removal as a function of residence time in the
hyporheic zone, J. Geophys. Res., 116, G01025, https://doi.org/10.1029/2010JG001356,
2011.
Zhang, Z., Schmidt, C., Nixdorf, E., Kuang, X., and Fleckenstein, J. H.: Effects of Heterogeneous Stream-Groundwater Exchange on the Source Composition of Stream Discharge and Solute Load, Water Resour. Res., 57, 1–19, https://doi.org/10.1029/2020WR029079, 2021.
Zheng, L., Cardenas, M. B., and Wang, L.: Temperature effects on nitrogen
cycling and nitrate removal-production efficiency in bed form-induced hyporheic zones, J. Geophys. Res.-Biogeo., 121, 1086–1103,
https://doi.org/10.1002/2015JG003162, 2016.
Ziegel, E. R., Gibbons, J., and Chakraborti, S.: Nonparametric Statistical
Inference, 5th Edn., CRC Press, Boca Raton, ISBN 978-1-4200-7762-9, https://doi.org/10.2307/1269693, 2011.
Short summary
In near-stream aquifers, mixing between stream water and ambient groundwater can lead to dilution and the removal of substances that can be harmful to the water ecosystem at high concentrations. We used a numerical model to track the spatiotemporal evolution of different water sources and their mixing around a stream, which are rather difficult in the field. Results show that mixing mainly develops as narrow spots, varying In time and space, and is affected by magnitudes of discharge events.
In near-stream aquifers, mixing between stream water and ambient groundwater can lead to...
