The relative contribution of near-bed vs. intragravel horizontal transport to fine sediment accumulation processes in river gravel beds

Geomorphology ◽  
2018 ◽  
Vol 303 ◽  
pp. 299-308 ◽  
Author(s):  
Roser Casas-Mulet ◽  
Garima Lakhanpal ◽  
Michael J. Stewardson
Keyword(s):  
Sediment Accumulation ◽  
Fine Sediment ◽  
Gravel Beds ◽  
Horizontal Transport ◽  
Relative Contribution

The HydroEcoSedimentary Tool: an integrated approach to characterise interstitial processes in freshwater systems

2021 ◽  
Author(s):  
Roser Casas-Mulet ◽  
Joachim Pander ◽  
Maximilian Prietzel ◽  
Juergen Geist
Keyword(s):  
Water Quality ◽  
Habitat Degradation ◽  
Human Impacts ◽  
Sediment Accumulation ◽  
Integrated Approach ◽  
Fine Sediment ◽  
Ecological Processes ◽  
Gravel Beds ◽  
Fine Sediments ◽  
A Site

<p>Increased deposition of fine sediments in streams affects a range of key ecosystem processes across the sediment-water interface, and it is a critical aspect of river habitat degradation and restoration. Understanding the mechanisms leading to fine sediment accumulation along and across streambeds, and their affectation to ecological processes is therefore essential for comprehending human impacts on river ecosystems and inform river restoration. Here, we introduce the HydroEcoSedimentary Tool (HEST) as an integrated approach to assess hydro-sedimentary and ecologically relevant processes together. The HEST integrates the estimation of a range of processes occurring in the interstitial zone, including sedimentary (fine sediment accumulation and fine sediment loss upon retrieval), hydraulic (hydraulic conductivity), geochemical (water quality and temperature) and ecological (with a focus on brown trout early life stages).</p><p>We tested the HEST application in two rivers with different degrees of morphological degradation in Germany. The HEST was successful in recording the set of key hydrosedimentary and ecologically relevant factors, and in providing a mechanistic linkage between and biological effect in a site-specific context. The HEST data confirmed that salmonid embryo mortality could be linked to high fine deposition in gravel beds. In addition, the HEST illustrated that such mortality could be linked explicitly to interstitial depths and to different infiltration pathways for fines (e.g. vertical vs. horizontal). Although interstitial water quality and temperature were within ecological thresholds and did not show significant differences with surface water, it was still useful to monitor such variables and to rule out any effect on mortality. Water temperature, for example, could be extremely important to detect local groundwater inputs, which has been demonstrated to have a significant effect on embryo salmonids elsewhere. The HEST also allowed accounting for the loss of fines during retrieval failure and estimating hydrological factors with the HEST illustrates its additional usefulness and reliability.</p><p>Compared to other methods, the HEST expands the possibilities to monitor and quantify fine sediment deposition in streambeds by differentiating between vertical, lateral and longitudinal infiltration pathways, and distinguishing between the depth (upper vs. lower layers) at which interstitial processes occur along the streambed column.</p>

Temporal and Spatial Quantification of Fine-Sediment Accumulation Downstream of Culverts in Brook Trout Habitat

2008 ◽  
Vol 137 (6) ◽  
pp. 1826-1838 ◽  
Author(s):  
Stephanie Lachance ◽  
Maryse Dubé ◽  
Renaud Dostie ◽  
Pierre Bérubé
Keyword(s):  
Brook Trout ◽  
Sediment Accumulation ◽  
Fine Sediment ◽  
Temporal And Spatial

scholarly journals Targeted water releases to flush fine sediment out of a bypassed reach of the Durance River downstream of four dams

2018 ◽  
Vol 40 ◽  
pp. 02048 ◽  
Author(s):  
Rémi Loire ◽  
Hervé Piégay ◽  
Jean-René Malavoi ◽  
Leah Bêche ◽  
Quentin Dumoutier ◽  
...  
Keyword(s):  
Power Plants ◽  
Initial Conditions ◽  
Sediment Accumulation ◽  
Monitoring Program ◽  
Field Measurements ◽  
Fine Sediment ◽  
Management Tool ◽  
Main Stream ◽  
Hydroelectric Power ◽  
Spawning Period

The Durance River is a highly regulated, gravel-bed river with a naturally high fine sediment load in southern France. EDF operates eight dams along the regulated main stream channel (218 km from the Serre-Ponçon Dam to the confluence with the Rhône River), that divert water to 16 hydroelectric power plants via a canal. Flow regulation has contributed to fine sediment accumulation (clogging) in the Durance River. In addition to a recent increase in minimum flows has implemented targeted water releases at four out of eight dams to simulate floods and reduce clogging to restore river function for fishes and invertebrates, The timing of these releases is defined for each dam based on the spawning period of target fish species. During the release, TSS, O2, T, H, and conductivity are measured continuously. Before and after each release, clogging (superficial/interstitial) is measured. This monitoring program showed that several of the releases were not effective on surface clogging inducing a loss of water or resulted in effects contrary to those sought, although this was not reflected in the biological results. These results indicate that two parameters must be taken into account to determine a priori the need to carry out releases: the hydrology observed during the year and the initial level of clogging. Artificial flood releases are increasingly being used a management tool to mitigate hydropower impacts on river hydromorphology and ecology. This experimentation shows that it is necessary to carry out these types of operations in an adaptive management context. At this time, the results obtained do not lead to clear conclusions regarding their efficacy, mostly as a result of strong interannual variation in hydroclimatic conditions, which have a strong influence on initial conditions and resulting outcomes. Furthermore, it is important to incorporate this field measurements and not rely solely on turbidity gauging stations to evaluate efficacy.

THE ASSESSMENT OF FINE SEDIMENT ACCUMULATION IN RIVERS USING MACRO-INVERTEBRATE COMMUNITY RESPONSE

2011 ◽  
Vol 29 (1) ◽  
pp. 17-55 ◽  
Author(s):  
C. A. Extence ◽  
R. P. CHADD ◽  
J. England ◽  
M. J. DUNBAR ◽  
P. J. WOOD ◽  
...  
Keyword(s):  
Sediment Accumulation ◽  
Community Response ◽  
Fine Sediment ◽  
Invertebrate Community
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