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33 results on '"Viparelli, E."'

5. River Response to Anthropogenic Modification: Channel Steepening and Gravel Front Fading in an Incising River

Author

Ylla Arbos, C. (author), Blom, A. (author), Viparelli, E. (author), Reneerkens, M. (author), Frings, R. M. (author), Schielen, R.M.J. (author), Ylla Arbos, C. (author), Blom, A. (author), Viparelli, E. (author), Reneerkens, M. (author), Frings, R. M. (author), and Schielen, R.M.J. (author)

Abstract

While most of the world's large rivers are heavily engineered, channel response to engineering measures on decadal to century and several 100 km scales is scarcely documented. We investigate the response of the Lower Rhine River (Germany-Netherlands) to engineering measures, in terms of channel slope and bed surface grain size. Field data show domain-wide incision, primarily associated with extensive channel narrowing. Remarkably, the channel slope has increased in the upstream end, which is uncommon under degradational conditions. We attribute the observed response to two competing mechanisms: bedrock at the upstream boundary increases the channel slope over the upstream part of the alluvial reach to compensate for the reduction of net annual sediment mobility, and extensive channel narrowing reduces the equilibrium slope. Another striking feature is the advance and flattening of the gravel-sand transition, suggesting its gradual fading due to an increasingly reduced slope difference between the gravel and sand reaches., Rivers, Ports, Waterways and Dredging Engineering

Published
2021
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11. Morphodynamics and Sediment Tracers in 1-D (MAST-ID): 1-D sediment transport that includes exchange with an off-channel sediment reservoir

Author

Lauer, J. Wesley, Li, C., Viparelli, E., Piégay, Hervé, TROUFLEAU, Pascal, Environnement, Ville, Société (EVS), École normale supérieure de Lyon (ENS de Lyon)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université Lumière - Lyon 2 (UL2)-Université Jean Moulin - Lyon 3 (UJML), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-École Nationale des Travaux Publics de l'État (ENTPE)-École nationale supérieure d'architecture de Lyon (ENSAL)-Centre National de la Recherche Scientifique (CNRS), Environnement Ville Société (EVS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École nationale supérieure d'architecture de Lyon (ENSAL)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Nationale des Travaux Publics de l'État (ENTPE)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Jean Moulin - Lyon 3 (UJML), and Université de Lyon-Université Lumière - Lyon 2 (UL2)-École normale supérieure - Lyon (ENS Lyon)

Subjects
1-D sediment transport, Morphodynamics and Sediment Tracers in 1-D (MAST-ID), off-channel sediment reservoir, [SHS] Humanities and Social Sciences, ComputingMilieux_MISCELLANEOUS, [SHS]Humanities and Social Sciences
Abstract

International audience

Published
2016

12. MAST-1D: A size-specific sediment transport and tracer model with off-channel storage

Author

Lauer, W., Viparelli, E., Piégay, Hervé, Environnement Ville Société (EVS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École nationale supérieure d'architecture de Lyon (ENSAL)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Nationale des Travaux Publics de l'État (ENTPE)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Jean Moulin - Lyon 3 (UJML), Université de Lyon-Université Lumière - Lyon 2 (UL2)-École normale supérieure - Lyon (ENS Lyon), ASCE, ANR-11-LABX-0010,DRIIHM / IRDHEI,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011), Environnement, Ville, Société (EVS), École normale supérieure de Lyon (ENS de Lyon)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université Lumière - Lyon 2 (UL2)-Université Jean Moulin - Lyon 3 (UJML), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-École Nationale des Travaux Publics de l'État (ENTPE)-École nationale supérieure d'architecture de Lyon (ENSAL)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-École nationale supérieure d'architecture de Lyon (ENSAL)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), and ANR-11-LABX-0010/11-LABX-0010,LabEx DRIIHM,Dispositif de recherche interdisciplinaire sur les Interactions Hommes-Milieux(2011)

Subjects
[SHS.ENVIR]Humanities and Social Sciences/Environmental studies, Channel, ComputingMilieux_MISCELLANEOUS, Modelling, sediment transport, [SHS]Humanities and Social Sciences
Abstract

International audience

Published
2014

13. A 1-D Size Specific Numerical Model for Gravel Transport that Includes Sediment Exchage with a Floodplain

Author

Lauer, W., Viparelli, E., Piégay, Hervé, Environnement Ville Société (EVS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-École nationale supérieure d'architecture de Lyon (ENSAL)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Nationale des Travaux Publics de l'État (ENTPE)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Jean Moulin - Lyon 3 (UJML), Université de Lyon-Université Lumière - Lyon 2 (UL2)-École normale supérieure - Lyon (ENS Lyon), EGU, 2014, Environnement, Ville, Société (EVS), École normale supérieure de Lyon (ENS de Lyon)-École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université Lumière - Lyon 2 (UL2)-Université Jean Moulin - Lyon 3 (UJML), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Jean Monnet - Saint-Étienne (UJM)-École Nationale des Travaux Publics de l'État (ENTPE)-École nationale supérieure d'architecture de Lyon (ENSAL)-Centre National de la Recherche Scientifique (CNRS), and TROUFLEAU, Pascal

Subjects
1-D size specific numerical model, gravel transport, sediment exchange with floodplains, [SHS] Humanities and Social Sciences, ComputingMilieux_MISCELLANEOUS, [SHS]Humanities and Social Sciences
Abstract

International audience

Published
2014

17. A Model to Predict the Evolution of a Gravel Bed River Under an Imposed Cyclic Hydrograph and its Application to the Trinity River

Author

Viparelli, E., Gaeuman, D., Wilcock, Peter, and Parker, G.

Subjects
Evolution, cyclic hydrograph, gravel bed river, Trinity River
Abstract

Major changes in the morphology of the Trinity River in California, such as narrowing of the cross section and sedimentation of fine sediment in pools, occurred after the closure of a system of dams. These changes caused a dramatic reduction in the salmonid population and a resulting decline of the fishery. Gravel augmentation, regulated flood releases, and mechanical channel rehabilitation are currently being implemented to help restore the aquatic habitat of the river. The present paper describes a tool, named the Spawning Gravel Refresher, for designing and predicting the effects of gravel augmentation in gravel bed rivers. The tool assumes an imposed, cycled hydrograph. The model is calibrated and applied to the regulated reach of the Trinity River in four steps: (1) zeroing runs to reproduce conditions of mobile bed equilibrium as best can be estimated for the predam Trinity River, (2) runs to compare the predictions with the results of previous studies, (3) runs at an engineering time scale to reproduce the effects of the dams, and (4) runs to design gravel augmentation schemes. In the fourth group of runs, the combined effects of engineered flood flow releases and gravel augmentation are predicted. At an engineering time scale, the model indicates that the fraction of fine sediment in the surface layer and in the topmost part of the substrate should decrease when subjected to these two restoration measures, with a consequent improvement of the quality of the spawning gravel.

Published
2011

20. Comparison between experimental and numerical stratigraphy emplaced by a prograding delta

Author

Viparelli, E. (author), Blom, A. (author), Ferrer-Boix, C. (author), Kuprenas, R. (author), Viparelli, E. (author), Blom, A. (author), Ferrer-Boix, C. (author), and Kuprenas, R. (author)

Abstract

A one-dimensional model that is able to store the stratigraphy emplaced by a prograding delta is validated against experimental results. The laboratory experiment describes the migration of a Gilbert delta on a sloping basement into standing water, i.e., a condition in which the stratigraphy emplaced by the delta front is entirely stored in the deposit. The migration of the delta front and the deposition on the delta top are modeled with total and grain-size-based mass conservation models. The vertical sorting on the delta front is modeled with a lee-face-sorting model as a function of the grain size distribution of the sediment deposited at the brinkpoint, i.e., at the downstream end of the delta top. Notwithstanding the errors associated with the grain-size-specific bedload transport formulation, the comparison between numerical and experimental results shows that the model is able to reasonably describe the progradation of the delta front, the frictional resistances on the delta top, and the overall grain size distribution of the delta top and delta front deposits. Further validation of the model in the case of variable base level is currently in progress to allow for future studies, at field and laboratory scale, on how the delta stratigraphy is affected by different changes of relative base level., Hydraulic Engineering, Civil Engineering and Geosciences

Published
2014
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30. Bar height formulas to predict the maximum scour depth at riverbanks

Author

G Del Giudice, G. Rasulo, E Viparelli, DEL GIUDICE, Giuseppe, Rasulo, Giacomo, and Viparelli, E.

Subjects
Bar (music), Geotechnical engineering, Geology
Abstract

FIoods in alluvial rivers are characterized by channels incision in the alluvial bed during the rising stage and their fìlling up in the falling stage; this phenomenon is well known and called scour and fill. In this work scour and fill during floods will be described as bar migration in the alluvial bed: when bar trough reaches the riverbank protection, the undermining of longitudinal protection structures may occur if the river bed level is lower than the bank foundation structure. Scour or trough depths below the average riverbed level can be predicted with formulas calibrated using flume data or derived theoretically. In this paper four different formulas for alternate bars will be discussed and their applicability to field data is tested. A simple criterion for riverbank foundation depth estimate is proposed and its applicability to braided rivers is derived by using a correction factor.

Published
2004

31. Modeling nanomaterial environmental fate in aquatic systems.

Author

Dale AL, Casman EA, Lowry GV, Lead JR, Viparelli E, and Baalousha M

Subjects
Models, Theoretical, Ecology, Marine Biology, Nanostructures, Risk Assessment
Abstract

Mathematical models improve our fundamental understanding of the environmental behavior, fate, and transport of engineered nanomaterials (NMs, chemical substances or materials roughly 1-100 nm in size) and facilitate risk assessment and management activities. Although today's large-scale environmental fate models for NMs are a considerable improvement over early efforts, a gap still remains between the experimental research performed to date on the environmental fate of NMs and its incorporation into models. This article provides an introduction to the current state of the science in modeling the fate and behavior of NMs in aquatic environments. We address the strengths and weaknesses of existing fate models, identify the challenges facing researchers in developing and validating these models, and offer a perspective on how these challenges can be addressed through the combined efforts of modelers and experimentalists.

Published
2015
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32. Large shift in source of fine sediment in the upper Mississippi river.

Author

Belmont P, Gran KB, Schottler SP, Wilcock PR, Day SS, Jennings C, Lauer JW, Viparelli E, Willenbring JK, Engstrom DR, and Parker G

Subjects
United States, Geologic Sediments analysis, Rivers
Abstract

Although sediment is a natural constituent of rivers, excess loading to rivers and streams is a leading cause of impairment and biodiversity loss. Remedial actions require identification of the sources and mechanisms of sediment supply. This task is complicated by the scale and complexity of large watersheds as well as changes in climate and land use that alter the drivers of sediment supply. Previous studies in Lake Pepin, a natural lake on the Mississippi River, indicate that sediment supply to the lake has increased 10-fold over the past 150 years. Herein we combine geochemical fingerprinting and a suite of geomorphic change detection techniques with a sediment mass balance for a tributary watershed to demonstrate that, although the sediment loading remains very large, the dominant source of sediment has shifted from agricultural soil erosion to accelerated erosion of stream banks and bluffs, driven by increased river discharge. Such hydrologic amplification of natural erosion processes calls for a new approach to watershed sediment modeling that explicitly accounts for channel and floodplain dynamics that amplify or dampen landscape processes. Further, this finding illustrates a new challenge in remediating nonpoint sediment pollution and indicates that management efforts must expand from soil erosion to factors contributing to increased water runoff.

Published
2011
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33. Natural processes in delta restoration: application to the Mississippi Delta.

Author

Paola C, Twilley RR, Edmonds DA, Kim W, Mohrig D, Parker G, Viparelli E, and Voller VR

Subjects
Geological Phenomena, Mississippi, Oceans and Seas, Conservation of Natural Resources methods, Rivers, Wetlands
Abstract

Restoration of river deltas involves diverting sediment and water from major channels into adjoining drowned areas, where the sediment can build new land and provide a platform for regenerating wetland ecosystems. Except for local engineered structures at the points of diversion, restoration mainly relies on natural delta-building processes. Present understanding of such processes is sufficient to provide a basis for determining the feasibility of restoration projects through quantitative estimates of land-building rates and sustainable wetland area under different scenarios of sediment supply, subsidence, and sea-level rise. We are not yet to the point of being able to predict the evolution of a restored delta in detail. Predictions of delta evolution are based on field studies of active deltas, deltas in mine-tailings ponds, experimental deltas, and countless natural experiments contained in the stratigraphic record. These studies provide input for a variety of mechanistic delta models, ranging from radially averaged formulations to more detailed models that can resolve channels, topography, and ecosystem processes. Especially exciting areas for future research include understanding the mechanisms by which deltaic channel networks self-organize, grow, and distribute sediment and nutrients over the delta surface and coupling these to ecosystem processes, especially the interplay of topography, network geometry, and ecosystem dynamics.

Published
2011
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