Variations de la conductivité hydraulique verticale du lit d’un cours d’eau avant et après une saison d’inondation

Wu, Guangxin; Shu, Longcang; Lu, Chengpeng; Chen, Xunhong; Zhang, Xiao; Appiah-Adjei, Emmanuel K.; Zhu, Jun Gao

doi:10.1007/s10040-015-1275-9

Cited by 32 publications

(23 citation statements)

References 32 publications

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“…In our study, we have used a reduced‐order numerical model of an idealized, uniform, and single type of bedform essentially to gain a deeper mechanistic understanding of the dynamic exchange processes occurring in HZs in result of peak flow events. While, for our systematic analyses, we considered a broad range of different scenario conditions (with regard to bedform topography, channel gradient, and peak flow event characteristics), there remain further variables and potentially impactful drivers that have not been analyzed in this study such as variability in streambed structural properties (Gomez‐Velez et al, ) or the impacts of critical flows with the potential to mobilize the streambed materials (Simpson & Meixner, ; Wu et al, ). Combination of several bedform morphologies with topographic structure of the catchment determines the overall HEF (Caruso et al, ; Schmadel et al, ; Ward et al, ).…”

Section: Discussionmentioning

confidence: 99%

Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform‐Induced Hyporheic Exchange

Singh

Gomez‐Velez

et al. 2019

Water Resources Research

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Discharge varies in space and time, driving hyporheic exchange processes in river corridors that affect biogeochemical cycling and ultimately control the dynamics of biogeochemical hot spots and hot moments. Herein, we use a reduced‐order model to conduct the systematic analysis of the interplay between discharge variability (peak flow intensities, duration, and skewness) and streambed topography (bedform aspect ratios and channel slopes) and their role in the flow and transport characteristics of hyporheic zones (HZs). We use a simple and robust conceptualization of single peak flow events for a series of periodic sinusoidal bedforms. Using the model, we estimate the spatial extent of the HZ, the total amount of exchange, and the residence time of water and solutes within the reactive environment and its duration relative to typical time scales for oxygen consumption (i.e., a measure of the denitrification potential). Our results demonstrate that HZ expansion and contraction is controlled by events yet modulated by ambient groundwater flow. Even though the change in hyporheic exchange flux (%) relative to baseflow conditions is invariant for different values of channel slopes, absolute magnitudes varied substantially. Primarily, peak flow events cause more discharge of older water for the higher aspect ratios (i.e., for dunes and ripples) and lower channel slopes. Variations in residence times during peak flow events lead to the development of larger areas of potential nitrification and denitrification in the HZ for longer durations. These findings have potential implications for river management and restoration, particularly the need for (re)consideration of the importance of hyporheic exchange under dynamic flow conditions.

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Section: Discussionmentioning

confidence: 99%

Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform‐Induced Hyporheic Exchange

Singh

Gomez‐Velez

et al. 2019

Water Resources Research

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“…In another study, Wu et al . [] measured the hydraulic conductivity of a streambed at more than 400 locations and identified statistically significant differences before and after the flood season. After the flood season, the mean and median hydraulic conductivity of the streambed decreased, and its variance increased indicating greater heterogeneity in the grain size distribution of the sediments forming the streambed.…”

Section: Streambed Dynamics In Relation To Hydraulic Propertiesmentioning

confidence: 99%

Blueprint for a coupled model of sedimentology, hydrology, and hydrogeology in streambeds

Partington

Therrien

Simmons

et al. 2017

Reviews of Geophysics

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The streambed constitutes the physical interface between the surface and the subsurface of a stream. Across all spatial scales, the physical properties of the streambed control surface water‐groundwater interactions. Continuous alteration of streambed properties such as topography or hydraulic conductivity occurs through erosion and sedimentation processes. Recent studies from the fields of ecology, hydrogeology, and sedimentology provide field evidence that sedimentological processes themselves can be heavily influenced by surface water‐groundwater interactions, giving rise to complex feedback mechanisms between sedimentology, hydrology, and hydrogeology. More explicitly, surface water‐groundwater exchanges play a significant role in the deposition of fine sediments, which in turn modify the hydraulic properties of the streambed. We explore these feedback mechanisms and critically review the extent of current interaction between the different disciplines. We identify opportunities to improve current modeling practices. For example, hydrogeological models treat the streambed as a static rather than a dynamic entity, while sedimentological models do not account for critical catchment processes such as surface water‐groundwater exchange. We propose a blueprint for a new modeling framework that bridges the conceptual gaps between sedimentology, hydrogeology, and hydrology. Specifically, this blueprint (1) fully integrates surface‐subsurface flows with erosion, transport, and deposition of sediments and (2) accounts for the dynamic changes in surface elevation and hydraulic conductivity of the streambed. Finally, we discuss the opportunities for new research within the coupled framework.

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“…Changes of up to two orders of magnitude of the streambed hydraulic conductivity after flood events have been documented in field studies [ Fette et al , ; Genereux et al , ; Hatch et al , ; Wu et al , ]. Such changes significantly affect the exchange fluxes between the surface and the groundwater domains.…”

Section: Introductionmentioning

confidence: 99%

Rapid identification of transience in streambed conductance by inversion of floodwave responses

Gianni

Richon

Perrochet

et al. 2016

Water Resources Research

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Streambed conductance controls the interaction between surface and groundwater. However, the streambed conductance is often subject to transience. Directly measuring hydraulic properties in a river yields only point values, is time‐consuming and therefore not suited to detect transience of physical properties. Here, we present a method to continuously monitor transience in streambed conductance. Input data are time series of stream stage and near stream hydraulic head. The method is based on the inversion of floodwave responses. The analytical model consists of three parameters: x, the distance between streambank and an observation well, α, the aquifer diffusivity, and a the retardation coefficient that is inversely proportional to the streambed conductance. Estimation of a is carried out over successive time steps in order to identify transience in streambed conductance. The method is tested using synthetic data and is applied to field data from the Rhône River and its alluvial aquifer (Switzerland). The synthetic method demonstrated the robustness of the proposed methodology. Application of the method to the field data allowed identifying transience in streambed properties, following flood events in the Rhône. This method requires transience in the surface water, and the river should not change its width significantly with a rising water level. If these conditions are fulfilled, this method allows for a rapid and effective identification of transience in streambed conductance.

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Variations de la conductivité hydraulique verticale du lit d’un cours d’eau avant et après une saison d’inondation

Cited by 32 publications

References 32 publications

Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform‐Induced Hyporheic Exchange

Dynamic Hyporheic Zones: Exploring the Role of Peak Flow Events on Bedform‐Induced Hyporheic Exchange

Blueprint for a coupled model of sedimentology, hydrology, and hydrogeology in streambeds

Rapid identification of transience in streambed conductance by inversion of floodwave responses

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