scholarly journals Geomorphic effects of gravel augmentation on the Old Rhine River downstream from the Kembs dam (France, Germany)

2018 ◽  
Vol 40 ◽  
pp. 02028 ◽  
Author(s):  
Valentin Chardon ◽  
Laurent Schmitt ◽  
Hervé Piégay ◽  
Fanny Arnaud ◽  
Jordane Serouilou ◽  
...  
Keyword(s):  
River Restoration ◽  
Sediment Supply ◽  
Shear Stresses ◽  
Rhine River ◽  
Hydraulic Modelling ◽  
Sediment Wave ◽  
Artificial Sediment ◽  
Upstream Part ◽  
Fluvial Ecosystems ◽  
Sediment Deposit

During the last 30 years, river restoration activities aiming to improve the functionality of degraded fluvial ecosystems increased markedly. For large rivers, it remains difficult to evaluate restoration efficiency and sustainability due to the lack of standardized monitoring metrics. From 2010 to 2016, three gravel augmentations were performed on the Old Rhine, a by-passed reach downstream from the Kembs dam (France- Germany). A geomorphic monitoring combining topo-bathymetric surveys, bedload tracking and hydraulic modelling allows to evaluate the successfulness of these actions. Results show that, to be mobilized, artificial sediment deposit should be located in concavity rather than convexity areas, due to higher shear stresses for moderate floods (Q2). Sediment starvation appeared rapidly on the restored reaches once the sediment wave moved downstream, as a consequence of limited upstream sediment supply. Bathymetric homogenization was observed along and downstream from the restored reaches without creation of new fluvial forms. This research highlights that future actions should include channel enlargement downstream of gravel augmentations, which would promote sediment deposition and habitat diversification. Sediments excavated during artificial widening could be stored and injected progressively into the upstream part of the Old Rhine to benefit the downstream sections.

scholarly journals Modern comprehensive approach to monitor the morphodynamic evolution of a restored river corridor

2011 ◽  
Vol 15 (4) ◽  
pp. 1197-1212 ◽  
Author(s):  
N. Pasquale ◽  
P. Perona ◽  
P. Schneider ◽  
J. Shrestha ◽  
A. Wombacher ◽  
...  
Keyword(s):  
River Restoration ◽  
Hydraulic Modeling ◽  
Research Groups ◽  
Alluvial Sediment ◽  
Scientific Project ◽  
Fluvial Ecosystems ◽  
Morphodynamic Evolution ◽  
Significant Effort ◽  
River Corridor

Abstract. River restoration has become a common measure to repair anthropogenically-induced alteration of fluvial ecosystems. The inherent complexity of ecohydrologic systems leads to limitations in understanding the response of such systems to restoration over time. Therefore, a significant effort has been dedicated in the recent years worldwide to document the efficiency of restoration actions and to produce new effective guidelines that may help overcoming existing deficiencies. At the same time little attention was paid to illustrate the reasons and the use of certain monitoring and experimental techniques in spite of others, or in relation to the specific ecohydrologic process being investigated. The purpose of this paper is to enrich efforts in this direction by presenting the framework of experimental activities and the related experimental setup that we designed and installed in order to accomplish some of the research tasks of the multidisciplinary scientific project RECORD (Restored Corridor Dynamics). Therein, we studied the morphodynamic evolution of the restored reach of the River Thur near Niederneunforn (Switzerland), also in relation to the role of pioneer vegetation roots in stabilizing the alluvial sediment. In this work we describe the methodology chosen for monitoring the river morphodynamics, the dynamics of riparian and of in-bed vegetation and their mutual interactions, as well as the need of complementing such observations with experiments and with the hydraulic modeling of the site. We also discuss how the designed installation and the experiments integrate with the needs of other research groups within the project, in particular providing data for a number of investigations thereby including surface water and groundwater interactions, soil moisture and vegetation dynamics.

scholarly journals Coupled Hydrological/Hydraulic Modelling of River Restoration Impacts and Floodplain Hydrodynamics

2016 ◽  
Vol 32 (9) ◽  
pp. 1927-1948 ◽  
Author(s):  
H. M. Clilverd ◽  
J. R. Thompson ◽  
C. M. Heppell ◽  
C. D. Sayer ◽  
J. C. Axmacher
Keyword(s):  
River Restoration ◽  
Hydraulic Modelling

Benchmarking Fluvial Dynamics for Process-Based River Restoration: the Upper Rhine River (1816-2014)

2016 ◽  
Vol 33 (3) ◽  
pp. 403-414 ◽  
Author(s):  
M. Diaz-Redondo ◽  
G. Egger ◽  
M. Marchamalo ◽  
S. Hohensinner ◽  
E. Dister
Keyword(s):  
River Restoration ◽  
Rhine River ◽  
Fluvial Dynamics ◽  
Upper Rhine

scholarly journals Balancing river restoration measures around a river bifurcation: A case study from the Netherlands

2018 ◽  
Vol 40 ◽  
pp. 06019
Author(s):  
Ralph Schielen ◽  
Bert Voortman ◽  
Tjeerd Driessen
Keyword(s):  
The Netherlands ◽  
River Restoration ◽  
Planning Process ◽  
Control Structure ◽  
Rhine River ◽  
Control Structures ◽  
Flood Level ◽  
Level Lowering ◽  
Restoration Measures

The Rhine River in the Netherlands still has some characteristics of a delta, although the river is extremely engineered and confined between dikes. An important characteristic are the bifurcation points where the river bifurcates into different branches. The discharge partitioning at the bifurcates is predefined, as this is an important element for the protection of the downstream branches. Adjustable control structures in the vicinity of the bifurcation point facilitate this setting. In order to mitigate higher discharges due to climate change, measures in the floodplains to reduce flood levels are projected. In the planning process, it is important to maintain the discharge partitioning and to guarantee a setting of the control structure such that some control space is left. This can be done by balancing measures. A measure which lowers the flood levels on one branch, should be balanced by another measure on the other branch in order to maintain the correct settings. This requires a careful planning process and careful considerations between flood level lowering and settings of the control structures.

scholarly journals Modern comprehensive approach to monitor the morphodynamic evolution of restored river corridors

2010 ◽  
Vol 7 (6) ◽  
pp. 8873-8912 ◽  
Author(s):  
N. Pasquale ◽  
P. Perona ◽  
P. Schneider ◽  
J. Shrestha ◽  
A. Wombacher ◽  
...  
Keyword(s):  
Vegetation Dynamics ◽  
River Restoration ◽  
Hydraulic Modeling ◽  
Research Groups ◽  
Alluvial Sediment ◽  
Scientific Project ◽  
Fluvial Ecosystems ◽  
River Corridors ◽  
Morphodynamic Evolution

Abstract. River restoration has become a common measure to repair anthropogenically-induced alteration of fluvial ecosystems. The inherent complexity of ecohydrologic systems, leads to limitations in understanding the response of such systems to restoration over time. Up to now a lot of effort has therefore been dedicated worldwide to document the efficiency of restoration actions and to produce new effective guidelines that may help overcoming our deficiencies. At the same time very few attentions focused on illustrating the reasons and the use of certain monitoring and experimental techniques in spite of others, or in relation to the specific ecohydrologic process being investigated. The purpose of this paper is to enrich efforts in this direction by discussing the experimental setup that we designed and installed in order to accomplish some of the research tasks of the multidisciplinary scientific project RECORD (Restored Corridor Dynamics). Therein, we study the morphodynamic evolution of the restored reaches of River Thur near Niederneunforn (Switzerland), also in relation to the role of pioneer vegetation roots in stabilizing the alluvial sediment. In this work we describe and motivate the methodology chosen for monitoring the river morphodynamics, the dynamics of riparian and of in-bed vegetation and their mutual interactions, as well as the need of complementing such observations with experiments and with the hydraulic modeling of the site. We also discuss how the designed installation and the experiments integrate with the needs of other research groups within the project, in particular providing data for a number of investigations ranging from surface water to groundwater, soil moisture and vegetation dynamics.

scholarly journals Degradational response of engineered channels to changes in the upstream controls and channel width: Simplified 1D numerical simulations

2018 ◽  
Vol 40 ◽  
pp. 03035
Author(s):  
Meles Siele ◽  
Astrid Blom ◽  
Enrica Viparelli
Keyword(s):  
Equilibrium State ◽  
Numerical Simulations ◽  
Constant Width ◽  
Water Discharge ◽  
Sediment Supply ◽  
Channel Width ◽  
Danube River ◽  
Rhine River ◽  
Supply Rate ◽  
The Elbe River

In response to changes in the upstream controls (i.e., the water discharge, the sediment supply rate, and the calibre of the load), engineered alluvial channels adjust their bed slope and bed surface texture to establish a new equilibrium state. Here we present and discuss various causes of degradational response of engineered channels to changes in the upstream controls and channel width. For that purpose, we apply a simplified 1D numerical research code to a schematic river reach of constant width consisting of mixed-size sediment, and assess its equilibrium state and transient response. We illustrate that the following perturbation to an initially equilibrium state lead to a degradational response: an increase of the water discharge, a decrease of the sediment supply rate, an increase of the sand content of the sediment supply, an increase of the gravel content of the sediment supply, and a decrease of the channel width. Degradational response under all conditions is associated with surface coarsening. The equilibrium states of the numerical simulations agree with analytical solutions. The results provide insight into the current degradational response of engineered rivers, such as the Rhine River, the Elbe River and the Danube River.

Effects of a river restoration project along the Old Rhine River (France-Germany): Response of macroinvertebrate communities

2019 ◽  
Vol 127 ◽  
pp. 114-124 ◽  
Author(s):  
Cybill Staentzel ◽  
Isabelle Combroux ◽  
Agnès Barillier ◽  
Corinne Grac ◽  
Etienne Chanez ◽  
...  
Keyword(s):  
River Restoration ◽  
Macroinvertebrate Communities ◽  
Rhine River ◽  
Restoration Project

Linkages between flow regime, biota, and ecosystem processes: Implications for river restoration

Science ◽  
2019 ◽  
Vol 365 (6459) ◽  
pp. eaaw2087 ◽  
Author(s):  
Margaret Palmer ◽  
Albert Ruhi
Keyword(s):  
River Restoration ◽  
Early Stage ◽  
Ecosystem Processes ◽  
Biological Processes ◽  
Regulated Rivers ◽  
Structure And Dynamics ◽  
Indirect Control ◽  
Global Biogeochemical Cycles ◽  
Composition Structure ◽  
Fluvial Ecosystems

River ecosystems are highly biodiverse, influence global biogeochemical cycles, and provide valued services. However, humans are increasingly degrading fluvial ecosystems by altering their streamflows. Effective river restoration requires advancing our mechanistic understanding of how flow regimes affect biota and ecosystem processes. Here, we review emerging advances in hydroecology relevant to this goal. Spatiotemporal variation in flow exerts direct and indirect control on the composition, structure, and dynamics of communities at local to regional scales. Streamflows also influence ecosystem processes, such as nutrient uptake and transformation, organic matter processing, and ecosystem metabolism. We are deepening our understanding of how biological processes, not just static patterns, affect and are affected by stream ecosystem processes. However, research on this nexus of flow-biota-ecosystem processes is at an early stage. We illustrate this frontier with evidence from highly altered regulated rivers and urban streams. We also identify research challenges that should be prioritized to advance process-based river restoration.

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