Numerical and Experimental Study of Favre Waves after Hydropowerplant Trigger with TELEMAC-3D

Hydrodynamic

Numerical and experimental study of Favre Waves with TELEMAC-3D and MASCARET

Water Qualit

Evaluation des stocks de sédiments fins au sein des retenues inhérentes aux barrages avant et après l’APAVER de mai 2021. OSR6 | Axe A - Action A3.2 | Rapport scientifique final

L’objectif de ce travail est d’évaluer les stocks de sédiments déposés dans la retenue de Génissiat et de Chautagne, suite à l’Abaissement PArtiel du barrage de VERbois (APAVER) du mois de mai 2021. La comparaison de profils géophysiques acquis par un sondeur de sédiment embarqué (Sub Bottom Profiler -SBP) avant et quelques semaines après l’événement, permet de montrer un dépôt non négligeable de sédiments. De plus, la méthode a permis de souligner des phases érosives plus anciennes (dragages, crues), des différentiels de sédimentation, des structures internes au dépôt, permettant, à terme, une interprétation efficace des phénomènes sédimentaires dans les retenues de barrage

Evaluation des stocks de sédiments fins au sein des retenues inhérentes aux barrages avant et après l’APAVER de mai 2021. OSR6 | Axe A - Action A3.2 | Rapport scientifique final

L’objectif de ce travail est d’évaluer les stocks de sédiments déposés dans la retenue de Génissiat et de Chautagne, suite à l’Abaissement PArtiel du barrage de VERbois (APAVER) du mois de mai 2021. La comparaison de profils géophysiques acquis par un sondeur de sédiment embarqué (Sub Bottom Profiler -SBP) avant et quelques semaines après l’événement, permet de montrer un dépôt non négligeable de sédiments. De plus, la méthode a permis de souligner des phases érosives plus anciennes (dragages, crues), des différentiels de sédimentation, des structures internes au dépôt, permettant, à terme, une interprétation efficace des phénomènes sédimentaires dans les retenues de barrage

Toward an operational approach for the characterization and modelling of fine sediments dynamics in reservoirs

Achieving a sustainable management of sediment fluxes in existing or proposed reservoirs is a challenging but essential requirement for dam operators. Such objective is of utmost importance to avoid sedimentation-related consequences. Numerical modelling is of great interest to understand the flow and sediment dynamics in a reservoir, to simulate the long-term evolution of sediment deposits and to evaluate the efficiency of various management strategies. This paper presents recent case studies, which validate the feasibility and relevancy of such technical option. The progresses obtained on essential stages of the numerical modelling of sediments dynamics in reservoirs are particularly emphasized. Concerning the distribution of deposits, a promising field method based on an optimum combination of direct samplings with acoustic measurements and video auscultations is detailed. Feedbacks are then provided concerning an innovative device deployed in the field for a direct measurement of the settling velocity. Issues about the assessment of calibration parameters are also addressed in this communication. Lab experiments performed on deposits sampled in several reservoirs provide practical guidance to evaluate the erosion parameters of sediments. Finally, several examples of sediment dynamics modelling in reservoirs including both cohesive and non-cohesive sediment are presented

Toward an operational approach for the characterization and modelling of fine sediments dynamics in reservoirs

Achieving a sustainable management of sediment fluxes in existing or proposed reservoirs is a challenging but essential requirement for dam operators. Such objective is of utmost importance to avoid sedimentation-related consequences. Numerical modelling is of great interest to understand the flow and sediment dynamics in a reservoir, to simulate the long-term evolution of sediment deposits and to evaluate the efficiency of various management strategies. This paper presents recent case studies, which validate the feasibility and relevancy of such technical option. The progresses obtained on essential stages of the numerical modelling of sediments dynamics in reservoirs are particularly emphasized. Concerning the distribution of deposits, a promising field method based on an optimum combination of direct samplings with acoustic measurements and video auscultations is detailed. Feedbacks are then provided concerning an innovative device deployed in the field for a direct measurement of the settling velocity. Issues about the assessment of calibration parameters are also addressed in this communication. Lab experiments performed on deposits sampled in several reservoirs provide practical guidance to evaluate the erosion parameters of sediments. Finally, several examples of sediment dynamics modelling in reservoirs including both cohesive and non-cohesive sediment are presented