# The Effect of Stream Discharge on Hyporheic Exchange

^{1}

^{2}

^{3}

^{4}

^{5}

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Materials and Methods

#### 2.1. Study Site

^{2}and an elevation range of 114–405 m a.s.l. Hydrological parameters were measured in Krycklan Catchment at 15 stations located in different parts of the catchment [43]. Krycklan Catchment is characterized by a cold and humid climate, featuring deep snow cover during the entire winter [44]. The 30-year (1981–2007) mean annual precipitation is 614 mm/year, 30–50% of which falls as snow [45]. The Quaternary deposits mostly consist of glacial till with a thickness of up to tens of meters [42].

#### 2.2. Field Measurement

#### 2.3. Field Data Analysis

#### 2.4. Modeling Framework

^{®}software to simulate a two-dimensional longitudinal transect along the center of the stream network. The Brinkman–Darcy equation (Equation (1)) was used with the continuity equation to describe the subsurface flow in the hyporheic zone near the streambed surface:

^{3}] is the water density, ε [–] is the Brinkman porosity,

**u**[m/s] is the subsurface velocity vector, t [s] is the time, p [pa] is the water pressure, μ [pa.s] is the water’s dynamic viscosity, μ

_{e}[pa.s] is the water’s effective viscosity, k [m

^{2}] is the intrinsic permeability of the sediment, and ($\frac{\mathsf{\mu}}{\mathrm{k}}u)$ is the Darcy term.

^{−9}[m

^{2}] representing the streambed sediment [18]) for the entire subsurface region. The second permeability scenario was performed by applying a decaying intrinsic permeability in the top meter of the subsurface region (starting with k = 10

^{−9}[m

^{2}] for the top surface decaying to k = 10

^{−12}[m

^{2}] at a depth of 1 m) and a constant intrinsic permeability (k = 10

^{−12}[m

^{2}] refers to the glacial sediment soil type) for the rest of the subsurface region (deeper than 1 m from the top surface). The depth-decaying function for the soil permeability was defined based on the findings of Morén et al. [18]. They performed an experiment in a small stream in Sweden (Tullstorps Brook) and measured the hydraulic conductivity at two depths (i.e., 3 and 7 cm) every 100 m for a reach of 1500 m. The permeability k(z) of the top meter of the stream was described according to [17]:

_{0}[m

^{2}] is the intrinsic permeability at the streambed interface, z [m] is the depth from the streambed, and c [m

^{−1}] is an empirical decay coefficient. An exponential function was fitted to the measured data of Morén et al. [18] with a lower hydraulic conductivity limit of K = 10

^{−6}[m/s] (corresponding to an intrinsic permeability of k = 10

^{−12}[m

^{2}]) for a depth of 1 m from the streambed surface (Figure S2, Supplementary Materials).

^{2}] is the gravitational acceleration, and ${d}_{i}\left(x\right)$ [m] is the water depth for each flow discharge. The water depth was quantified using the corresponding mean discharge value for each flow discharge (see Section 2.3). Furthermore, an open boundary was assumed for the upstream and downstream sides, whereas a no-flow boundary was considered for the bottom surface of the model. Each model was run to a steady state flow condition based on hydrostatic head boundary condition on the top surface.

## 3. Results

#### 3.1. Water Temperature

#### 3.2. Modeling Results

_{HF,max}). Figure 5 shows the calculated maximum depths of the hyporheic fluxes for the case of constant permeability (Figure 5a) and decaying permeability in the top meter of the flow domain (Figure 5b). The results indicate that D

_{HF,max}varied during the three flow discharges. In particular, the minimum D

_{HF,max}is highly affected by stream water flow intensity (the range of D

_{HF,max}is affected by the order of 10 and 100 in constant and decaying permeability scenarios, respectively). High-flow discharges have lower values of D

_{HF,max}than the base-flow discharge, whereas the minimum D

_{HF,max}for the base flow is higher than that for low-flow discharge, regardless of the permeability scenario applied. The median value of D

_{HF,max}varies slightly between different flow discharges, with the low-flow discharge having the highest median value of D

_{HF,max}among all the flow discharges, i.e., 4 m and 0.03 m in constant and decaying permeability scenarios, respectively (Figure S3 in the Supplementary Materials). However, in the case of decaying permeability, the median value of D

_{HF,max}(Figure 5b) is in the range of centimeters which is substantially lower than in the constant permeability case (Figure 5a) that is in a range of meters. Additionally, the logarithmic ranges of interquartile of the maximum depth of the hyporheic fluxes in the constant permeability case (Figure 5a) are smaller than those in the decaying permeability scenario (Figure 5b) for all flow discharges.

## 4. Discussion

#### 4.1. Temperature Variation in the Streambed Sediment

#### 4.2. The Role of the Heterogeneity of Sediment Permeability in Hyporheic Exchange

## 5. Conclusions

## Supplementary Materials

**a**) constant intrinsic permeability (k = 10

^{−9}[m

^{2}]) for the entire subsurface region and (

**b**) decaying intrinsic permeability (starting from k(z = 0) = 10

^{−9}[m

^{2}] at the surface–subsurface water interface and decaying exponentially to k(z = –1) = 10

^{−12}[m

^{2}] down to a depth of 1 m). In the case of vertically varying permeability, a constant permeability (k = 10

^{−12}) was used for depths larger than 1 m.”, Table S1: “Correlation between discharge and mean water depth using five flow data for every 50 m distance from upstream along the main river”, Table S2: “Estimated mean water depth for different flow condition every 50 m from upstream”.

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

- Cardenas, M.B. Hyporheic zone hydrologic science: A historical account of its emergence and a prospectus. Water Resour. Res.
**2015**, 51, 3601–3616. [Google Scholar] [CrossRef] - Tonina, D.; Buffington, J.M. Effects of stream discharge, alluvial depth and bar amplitude on hyporheic flow in pool-riffle channels. Water Resour. Res.
**2011**, 47. [Google Scholar] [CrossRef] - Stanford, J.A.; Ward, J.V. The hyporheic habitat of river ecosystems. Nature
**1988**, 335, 64–66. [Google Scholar] [CrossRef] - Sawyer, A.H.; Bayani Cardenas, M.; Buttles, J. Hyporheic temperature 165 dynamics and heat exchange near channel-spanning logs. Water Resour. Res.
**2012**, 48. [Google Scholar] [CrossRef] - Harvey, J.W.; Böhlke, J.K.; Voytek, M.A.; Scott, D.; Tobias, C.R. Hyporheic zone denitrification: Controls on effective reaction depth and contribution to whole stream mass balance. Water Resour. Res.
**2013**, 49, 6298–6316. [Google Scholar] [CrossRef] - Boano, F.; Camporeale, C.; Revelli, R.; Ridolfi, L. Sinuosity-driven hyporheic exchange in meandering rivers. Geophys. Res. Lett.
**2006**, 33. [Google Scholar] [CrossRef] - Elliott, A.H.; Brooks, N.H. Transfer of nonsorbing solutes to a streambed with bed forms: Theory. Water Resour. Res.
**1997**, 33, 123–136. [Google Scholar] [CrossRef] - Gomez-Velez, J.D.; Krause, S.; Wilson, J.L. Effect of low-permeability layers on spatial patterns of hyporheic exchange and groundwater upwelling. Water Resour. Res.
**2014**, 50, 5196–5215. [Google Scholar] [CrossRef][Green Version] - Stonedahl, S.H.; Harvey, J.W.; Packman, A.I. Interactions between hyporheic flow produced by stream meanders, bars, and dunes. Water Resour. Res.
**2013**, 49, 5450–5461. [Google Scholar] [CrossRef] - Sawyer, A.H.; Cardenas, M.B.; Bomar, A.; Mackey, M. Impact of dam operations on hyporheic exchange in the riparian zone of a regulated river. Hydrol. Process.
**2009**, 23, 2129–2137. [Google Scholar] [CrossRef] - McGlynn, B.L.; McDonnell, J.J.; Shanley, J.B.; Kendall, C. Riparian zone flowpath dynamics during snowmelt in a small headwater catchment. J. Hydrol.
**1999**, 222, 75–92. [Google Scholar] [CrossRef] - Malcolm, I.A.; Soulsby, C.; Youngson, A.F.; Petry, J. Heterogeneity in ground water–surface water interactions in the hyporheic zone of a salmonid spawning stream. Hydrol. Process.
**2003**, 17, 601–617. [Google Scholar] [CrossRef] - Schmidt, C.; Bayer-Raich, M.; Schirmer, M. Characterization of spatial heterogeneity of groundwater-stream water interactions using multiple depth streambed temperature measurements at the reach scale. Hydrol. Earth Syst. Sci. Discuss.
**2006**, 3, 1419–1446. [Google Scholar] [CrossRef][Green Version] - Boano, F.; Revelli, R.; Ridolfi, L. Reduction of the hyporheic zone volume due to the stream-aquifer interaction. Geophys. Res. Lett.
**2008**, 35, L09401. [Google Scholar] [CrossRef] - Mojarrad, B.B.; Riml, J.; Wörman, A.; Laudon, H. Fragmentation of the hyporheic zone due to regional groundwater circulation. Water Resour. Res.
**2019**, 55, 1242–1262. [Google Scholar] [CrossRef] - Saar, M.O.; Manga, M. Depth dependence of permeability in the Oregon Cascades inferred from hydrogeologic, thermal, seismic, and magmatic modeling constraints. J. Geophys. Res.
**2004**, 109, B04204. [Google Scholar] [CrossRef] - Marklund, L.; Wörman, A. The use of spectral analysis-based exact solutions to characterize topography-controlled groundwater flow. Hydrogeol. J.
**2011**, 19, 1531–1543. [Google Scholar] [CrossRef] - Morén, I.; Wörman, A.; Riml, J. Design of remediation actions for nutrient mitigation in the hyporheic zone. Water Resour. Res.
**2017**, 53, 8872–8899. [Google Scholar] [CrossRef] - Brunke, M.; Gonser, T. The ecological significance of exchange processes between rivers and groundwater. Freshwater Biol.
**1997**, 37, 1–33. [Google Scholar] [CrossRef][Green Version] - Conant, B.; Cherry, J.; Gillham, R. A PCE groundwater plume discharging to a river: Influence of the streambed and near-river zone on contaminant distributions. J. Contam. Hydrol.
**2004**, 73, 249–279. [Google Scholar] [CrossRef] - Kalbus, E.; Schmidt, C.; Bayer-Raich, M.; Leschik, S.; Reinstorf, F.; Balcke, G.; Schirmer, M. New methodology to investigate potential contaminant mass fluxes at the stream-aquifer interface by combining integral pumping tests and streambed temperatures. Environ. Pollut.
**2007**, 148, 808–816. [Google Scholar] [CrossRef] [PubMed] - Chapman, S.W.; Parker, B.L.; Cherry, J.A.; Aravena, R.; Hunkeler, D. Groundwater-surface water interaction and its role on TCE groundwater plume attenuation. J. Contam. Hydrol.
**2007**, 91, 203–232. [Google Scholar] [CrossRef] [PubMed] - Kalbus, E.; Reinstorf, F.; Schirmer, M. Measuring methods for groundwater? Surface water interactions: A review. Hydrol. Earth Syst. Sci.
**2006**, 10, 873–887. [Google Scholar] [CrossRef] - Anderson, M.P. Heat as a ground water tracer. Groundwater
**2005**, 43, 951–968. [Google Scholar] [CrossRef] [PubMed] - Conant, B. Delineating and quantifying ground water discharge zones using streambed temperatures. Groundwater
**2004**, 42, 243–257. [Google Scholar] [CrossRef] - Constantz, J. Heat as a tracer to determine streambed water exchanges. Water Resour. Res.
**2008**, 44. [Google Scholar] [CrossRef] - Rau, G.C.; Andersen, M.S.; McCallum, A.M.; Acworth, R.I. Analytical methods that use natural heat as a tracer to quantify surface water–groundwater exchange, evaluated using field temperature records. Hydrogeol. J.
**2010**, 18, 1093–1110. [Google Scholar] [CrossRef] - Krause, S.; Blume, T. Impact of seasonal variability and monitoring mode on the adequacy of fiber-optic distributed temperature sensing at aquifer-river interfaces. Water Resour. Res.
**2013**, 49, 2408–2423. [Google Scholar] [CrossRef] - Selker, J.; van de Giesen, N.; Westhoff, M.; Luxemburg, W.; Parlange, M.B. Fiber optics opens window on stream dynamics. Geophys. Res. Lett.
**2006**, 33. [Google Scholar] [CrossRef][Green Version] - Selker, J.S.; Thévenaz, L.; Huwald, H.; Mallet, A.; Luxemburg, W.; Van De Giesen, N.; Stejskal, M.; Zeman, J.; Westhoff, M.; Parlange, M.B. Distributed fiber-optic temperature sensing for hydrologic systems. Water Resour. Res.
**2006**, 42. [Google Scholar] [CrossRef][Green Version] - Krause, S.; Hannah, D.M.; Fleckenstein, J.H.; Heppell, C.M.; Kaeser, D.; Pickup, R.; Pinay, G.; Robertson, A.L.; Wood, P.J. Inter-disciplinary perspectives on processes in the hyporheic zone. Ecohydrology
**2011**, 4, 481–499. [Google Scholar] [CrossRef] - Boano, F.; Revelli, R.; Ridolfi, L. Modeling hyporheic exchange with unsteady stream discharge and bedform dynamics. Water Resour. Res.
**2013**, 49, 4089–4099. [Google Scholar] [CrossRef] - Gomez-Velez, J.D.; Wilson, J.L.; Cardenas, M.B.; Harvey, J.W. Flow and residence times of dynamic river bank storage and sinuosity-driven hyporheic exchange. Water Resour. Res.
**2017**, 53, 8572–8595. [Google Scholar] [CrossRef] - Malzone, J.M.; Anseeuw, S.K.; Lowry, C.S.; Allen-King, R. Temporal hyporheic zone response to water table fluctuations. Groundwater
**2016**, 54, 274–285. [Google Scholar] [CrossRef] [PubMed] - Malzone, J.M.; Lowry, C.S.; Ward, A.S. Response of the hyporheic zone to transient groundwater fluctuations on the annual and storm event time scales. Water Resour. Res.
**2016**, 52, 5301–5321. [Google Scholar] [CrossRef] - Schmadel, N.M.; Ward, A.S.; Lowry, C.S.; Malzone, J.M. Hyporheic exchange controlled by dynamic hydrologic boundary conditions. Geophys. Res. Lett.
**2016**, 43, 4408–4417. [Google Scholar] [CrossRef][Green Version] - Trauth, N.; Fleckenstein, J.H. Single discharge events increase reactive efficiency of the hyporheic zone. Water Resour. Res.
**2017**, 53, 779–798. [Google Scholar] [CrossRef] - Singh, T.; Wu, L.; Gomez-Velez, J.D.; Lewandowski, J.; Hannah, D.M.; Krause, S. Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform-Induced Hyporheic Exchange. Water Resour. Res.
**2019**, 55, 218–235. [Google Scholar] [CrossRef] - McCallum, J.L.; Shanafield, M. Residence times of stream-groundwater exchanges due to transient stream stage fluctuations. Water Resour. Res.
**2016**, 52, 2059–2073. [Google Scholar] [CrossRef] - Sickbert, T.; Peterson, E.W. The effects of surface water velocity on hyporheic interchange. J. Water Resour. Prot.
**2014**, 6, 327–336. [Google Scholar] [CrossRef] - Wroblicky, G.; Campana, M.; Valett, H.; Dahm, C. Seasonal variation in surface-subsurface water exchange and lateral hyporheic area of two stream-aquifer systems. Water Resour. Res.
**1998**, 34, 317–328. [Google Scholar] [CrossRef] - Laudon, H.; Taberman, I.; Agren, A.; Futter, M.; Ottosson-Löfvenius, M.; Bishop, K. The Krycklan Catchment Study: A flagship infrastructure for hydrology, biogeochemistry, and climate research in the boreal landscape. Water Resour. Res.
**2013**, 49, 7154–7158. [Google Scholar] [CrossRef] - Karlsen, R.H.; Grabs, T.; Bishop, K.; Buffam, I.; Laudon, H.; Seibert, J. Landscape controls on spatiotemporal discharge variability in a boreal catchment. Water Resour. Res.
**2016**, 52, 6541–6556. [Google Scholar] [CrossRef][Green Version] - Leach, J.A.; Lidberg, W.; Kuglerová, L.; Peralta-Tapia, A.; Ågren, A.; Laudon, H. Evaluating topography-based predictions of shallow lateral groundwater discharge zones for a boreal lake-stream system. Water Resour. Res.
**2017**, 53, 5420–5437. [Google Scholar] [CrossRef] - Laudon, H.; Ottosson-Löfvenius, M. Adding snow to the picture: Providing complementary winter precipitation data to the Krycklan catchment study database. Hydrol. Process.
**2016**, 30, 2413–2416. [Google Scholar] [CrossRef] - Lupon, A.; Denfeld, B.A.; Laudon, H.; Leach, J.; Karlsson, J.; Sponseller, R.A. Groundwater inflows control patterns and sources of greenhouse gas emissions from streams. Limnol. Oceanogr.
**2019**, 64. [Google Scholar] [CrossRef] - Munz, M.; Oswald, S.E.; Schmidt, C. Sand box experiments to evaluate the influence of subsurface temperature probe design on temperature based water flux calculation. Hydrol. Earth Syst. Sci.
**2011**, 15, 3495–3510. [Google Scholar] [CrossRef][Green Version] - Sterte, E.J.; Johansson, E.; Sjöberg, Y.; Karlsen, R.H.; Laudon, H. Groundwater-surface water interactions across scales in a boreal landscape investigated using a numerical modelling approach. J. Hydrol.
**2018**, 560, 184–201. [Google Scholar] [CrossRef] - Briggs, M.A.; Lautz, L.K.; Buckley, S.F.; Lane, J.W. Practical limitations on the use of diurnal temperature signals to quantify groundwater upwelling. J. Hydrol.
**2014**, 519, 1739–1751. [Google Scholar] [CrossRef] - Shanafield, M.; Hatch, C.; Pohll, G. Uncertainty in thermal time series analysis estimates of streambed water flux. Water Resour. Res.
**2011**, 47. [Google Scholar] [CrossRef] - Taniguchi, M. Evaluation of vertical groundwater fluxes and thermal properties of aquifers based on transient temperature-depth profiles. Water Resour. Res.
**1993**, 29, 2021–2026. [Google Scholar] [CrossRef] - Cardenas, M.B.; Wilson, J.L.; Zlotnik, V.A. Impact of heterogeneity, bed forms, and stream curvature on subchannel hyporheic exchange. Water Resour. Res.
**2004**, 40, W08307. [Google Scholar] [CrossRef] - Salehin, M.; Packman, A.I.; Paradis, M. Hyporheic exchange with heterogeneous streambeds: Laboratory experiments and modeling. Water Resour. Res.
**2004**, 40, W11504. [Google Scholar] [CrossRef]

**Figure 1.**Map showing the experimental subcatchment and its topography, the main river (dark blue color), tributaries (cyan color), Lake Stortjärn (solid light blue region), and hydrological stations C5 and C6. Also shown are the locations of the V-notch weir (red flag) and temperature lances (yellow stars).

**Figure 2.**Relationships between discharge and water depth at a spatial resolution of 50 m (one of the discharge values at a distance of 550 m from the upstream station (shown with a magenta star) was not considered in the analysis due to its unrealistic value, which might be due to measurement error).

**Figure 3.**Water temperature time series measured at different locations along the stream network for different flow discharges. Each color represents the temperature recorded by sensors at increasing depth. Colors range from brown to blue as depth increases. Temperatures were not properly recorded during the first 20 h by the temperature stick located 350 m from the upstream station (panel g), and these were therefore neglected. High-flow discharge corresponds to high flow 1 period of Table 2.

**Figure 4.**Vertical envelopes of temperature dynamics during base-, low-, and high-flow discharges at different monitoring locations. The envelopes indicate the interquartile range (shaded area) and the median (red line).

**Figure 5.**Boxplots showing the maximum depth of hyporheic fluxes under various flow discharges assuming (

**a**) constant intrinsic permeability (k = 10

^{−9}[m

^{2}]) for the entire subsurface region and (

**b**) a decaying intrinsic permeability (starting from k(z = 0) = 10

^{−9}[m

^{2}] at the surface–subsurface water interface and decaying exponentially to k(z = −1) = 10

^{−12}[m

^{2}] at one meter depth). In the case of a vertically varying permeability, a constant permeability (k = 10

^{−12}) was used for depths larger than one meter. The second row of the horizontal axis (i.e., numbers), are the ranges of stream flow discharge along the stream for each flow regime. D

_{HF,max}: deepest point of the streamlines.

**Figure 6.**Box and whisker plots of hyporheic fluxes residence time under various flow discharges assuming (

**a**) constant intrinsic permeability (k = 10

^{−9}[m

^{2}]) for the entire subsurface region and (

**b**) decaying intrinsic permeability (starting from k(z = 0) = 10

^{−9}[m

^{2}] at the surface–subsurface water interface and decaying exponentially to k(z = −1) = 10

^{−12}[m

^{2}] down to a depth of 1 m). In the case of vertically varying permeability, a constant permeability (k = 10

^{−12}) was used for depths larger than 1 m. The second row of the horizontal axis (i.e., numbers), are the ranges of stream flow discharge along the stream for each flow regime. τ: residence time of the particles released at the streambed interface.

**Figure 7.**Cumulative distribution function of the length distribution of spatially coherent upwelling/downwelling stretches at the streambed interface under various flow discharges, assuming (

**a**) constant intrinsic permeability (k = 10

^{−9}[m

^{2}]) for the entire subsurface region, and (

**b**) a decaying intrinsic permeability.

**Table 1.**Estimated stream discharge values based on measured streamflow data and drainage area (Q), and measured mean water depth (d) for different flow discharges at 50 m spatial resolution.

Distance from Upstream Station [m] | Drainage Area [m^{2}] | Snow Melt Flow (22 May 2017) | Summer Base Flow (27 June 2017) | Low Flow (18 August 2017) | High Flow (19 August 2017) | Autumn Base Flow (30 August 2017) | |||||

Q [L/s] | d [cm] | Q [L/s] | d [cm] | Q [L/s] | d [cm] | Q [L/s] | d [cm] | Q [L/s] | d [cm] | ||

0 | 234,446 | 54.48 | 31 | 2.63 | 11 | 0.19 | 3 | 25.58 | 17 | 7.36 | 9 |

50 | 236,031 | 54.54 | 31 | 2.65 | 11 | 0.19 | 3 | 25.59 | 17 | 7.42 | 9 |

100 | 243,262 | 54.81 | 31 | 2.76 | 11 | 0.21 | 2 | 25.63 | 11 | 7.48 | 7 |

150 | 250,838 | 55.09 | 32 | 2.86 | 15 | 0.23 | 18 | 25.67 | 24 | 7.55 | 26 |

200 | 258,334 | 55.37 | 28 | 2.97 | 17 | 0.26 | 21 | 25.71 | 35 | 7.61 | 25 |

250 | 262,731 | 55.53 | 32 | 3.03 | 9 | 0.27 | 8 | 25.74 | 26 | 7.67 | 14 |

300 | 265,497 | 55.63 | 33 | 3.07 | 19 | 0.27 | 7 | 25.76 | 16 | 7.73 | 13 |

350 | 267,926 | 55.72 | 27 | 3.11 | 7 | 0.28 | 6 | 25.77 | 8 | 7.79 | 10 |

400 | 291,324 | 56.59 | 27 | 3.44 | 11 | 0.35 | 9 | 25.90 | 12 | 7.86 | 6 |

450 | 293,516 | 56.67 | 29 | 3.47 | 0.35 | 7 | 25.91 | 19 | 7.92 | 14 | |

500 | 296,214 | 56.77 | 21 | 3.51 | 0.36 | 5 | 25.93 | 16 | 7.98 | 10 | |

550 | 337,040 | 58.29 | 20 | 4.09 | 0.47 | 26 | 26.16 | 34 | 8.04 | 22 | |

600 | 343,055 | 58.51 | 42 | 4.17 | 0.49 | 15 | 26.19 | 24 | 8.11 | 16 | |

650 | 357,882 | 59.07 | 32 | 4.39 | 0.53 | 8 | 26.28 | 19 | 8.17 | 13 | |

700 | 373439 | 59.64 | 29 | 4.61 | 0.57 | 19 | 26.37 | 33 | 8.23 | 27 | |

750 | 375,921 | 59.74 | 27 | 4.64 | 0.58 | 14 | 26.38 | 20 | 8.29 | 11 | |

800 | 379,197 | 59.86 | 35 | 4.69 | 0.58 | 5 | 26.40 | 15 | 8.35 | 5 | |

850 | 396,899 | 60.52 | 22 | 4.94 | 0.63 | 5 | 26.50 | 16 | 8.42 | 17 | |

900 | 405,145 | 60.82 | 15 | 5.06 | 0.66 | 9 | 26.54 | 16 | 8.48 | 12 | |

950 | 411,322 | 61.05 | 26 | 5.14 | 0.67 | 4 | 26.58 | 19 | 8.54 | 14 | |

1000 | 413,347 | 61.13 | 29 | 5.17 | 0.68 | 24 | 26.59 | 29 | 8.60 | 29 | |

1050 | 535,591 | 65.67 | 31 | 6.91 | 1.01 | 6 | 27.28 | 17 | 8.66 | 10 | |

1100 | 558,355 | 66.51 | 21 | 7.24 | 1.07 | 4 | 27.41 | 9 | 8.73 | 8 | |

1150 | 567,113 | 66.84 | 14 | 7.36 | 1.10 | 2 | 27.46 | 9 | 8.79 | 5 | |

1200 | 568,492 | 66.89 | 28 | 7.38 | 1.10 | 2 | 27.47 | 20 | 8.85 | 4 | |

1250 | 573,211 | 67.07 | 30 | 7.45 | 1.11 | 14 | 27.49 | 23 | 8.91 | 20 | |

1300 | 578,673 | 67.27 | 35 | 7.52 | 1.13 | 19 | 27.52 | 32 | 8.98 | 26 | |

1437 | 648,703 | 69.87 | 35 | 8.52 | 1.32 | 19 | 27.92 | 32 | 9.19 | 26 |

Flow Discharge | Time Period | Mean Upstream Discharge [L/s] | Mean Downstream Discharge [L/s] |
---|---|---|---|

Base flow | 03–07August | 8.71 | 10.8 |

Low flow | 07–19 August | 0.22 | 1.56 |

High flow 1 | 19 August | 25.59 | 27.96 |

High flow 2 | 21 August | 25.57 | 30.09 |

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Mojarrad, B.B.; Betterle, A.; Singh, T.; Olid, C.; Wörman, A. The Effect of Stream Discharge on Hyporheic Exchange. *Water* **2019**, *11*, 1436.
https://doi.org/10.3390/w11071436

**AMA Style**

Mojarrad BB, Betterle A, Singh T, Olid C, Wörman A. The Effect of Stream Discharge on Hyporheic Exchange. *Water*. 2019; 11(7):1436.
https://doi.org/10.3390/w11071436

**Chicago/Turabian Style**

Mojarrad, Brian Babak, Andrea Betterle, Tanu Singh, Carolina Olid, and Anders Wörman. 2019. "The Effect of Stream Discharge on Hyporheic Exchange" *Water* 11, no. 7: 1436.
https://doi.org/10.3390/w11071436