Publications

2019

• A simple SPH model of a free surface water wave pump: waves above a submerged plate
  
  • Carmigniani Rémi
  • Leroy Agnès
  • Violeau Damien
  Coastal Engineering Journal, World Scientific Publishing, 2019, 61 (1), pp.96-108. (10.1080/21664250.2018.1560923)
  DOI : 10.1080/21664250.2018.1560923
• River estuaries of the Amazon-influenced Guianas coast: diversity and preliminary classification
  
  • Gardel Antoine
  • Anthony Edward J.
  • Huybrechts Nicolas
  • Lesourd Sandric
  • Santos Valdenira
  • Sottolichio Aldo
  , 2019, 21. The morphology and dynamics of the 1500 km-long Guianas coast, South America, are strongly influenced by mud supplied by the Amazon River. A fraction of this mud (20% of nearly 1 billion tons annually) is organized into large banks that migrate along the coast under the influence of waves and currents, separated by 'inter-bank' zones. 'Bank' zones significantly dissipate the wave energy transmitted shoreward, whereas inter-bank zones are commonly characterized by a relatively mud-free shoreface, and wave energy is thus more efficiently transmitted to the shore. The alongshore alternation of shifting bank and inter-bank zones is strongly modulated by water discharge from the local rivers, which depends essentially on catchment size. The hydrology and sediment fluxes of many of these rivers, which drain the crystalline rocks of the Guiana Shield between the Amazon and the Orinoco River deltas, are still largely unknown. Even the catchment size of several of these rivers is not known with certainty. The relationship between discharge from these Guiana Shield rivers and the Amazon mud-bank belts results in a variety of estuarine morphological and dynamic configurations. Further estuarine diversity is engendered by lithology. A preliminary classification of 15 estuaries, based on plan morphology and ongoing analyses of estuarine hydrodynamics, suggests four basic types: (1) estuaries fixed by headlands of Precambrian basement rocks (Mahury, Cayenne, and Kourou Rivers); these are associated with small catchments and found only in French Guiana, where the basement crops out along the coast; (2) estuaries with mouths diverted westward (the direction of regional alongshore sediment transport) by prograded mud capes and spits, reflecting a significant influence of multi-decadal to multi-millennial coastal accretion of Amazon-derived mud (Cassipore, Uaça, Rivers in Amapa, Brazil; Oyapock between Brazil and French Guyana; Approuague, Sinnamary and Mana Rivers in French Guyana; Suriname and Coppename Rivers in Suriname; Berbice River in Guyana); (3) estuaries oriented normal to the coast and associated with relatively large-discharge rivers (Maroni River between French Guiana and Suriname; Corentyne River between Suriname and Guyana; (4) a prograded estuary mouth with a transitional morphology towards a delta (Essequibo River in Guyana, the largest river on the Guianas coast after the Amazon and the Orinoco). Ongoing monitoring of the sediment fluxes and hydrodynamics of a type 1 (Mahury) and a type 3 estuary (Maroni), both of which are fixed (lithologically for type 1, and hydrodynamically for type 3), and akin, morphologically, to normal trumpet-or funnel-shaped estuaries, shows a tropical seasonal regime but which is strongly influenced by Amazon mud during the low-discharge dry season. This mud influence from the distant Amazon constitutes a unique aspect of the river mouths on the Guianas coast.
• A possible solution for flood risk mitigation in Ho Chi Minh City and the lower Sai Gon-Dong Nai River Basin
  
  • Dinh Cong San
  • Nguyen Binh Duong
  • Nguyen Kim Dan
  • Nguyen Van-Thanh-Van
  La Houille Blanche - Revue internationale de l'eau, EDP Sciences, 2019, 105 (5-6), pp.114 - 123. The Sai Gon-Dong Nai Basin plays a very important role in the socioeconomic development of Vietnam. The area of Ho Chi Minh (HCM) City is about 2095 km 2 , 60% of which lying under 2 m above MSL. Its population is about 8.136 million. Economic development has led to flood-related problems. The causes of floods are monsoon rainfalls, high tides, and outflows from the Dau Tieng Reservoir, upstream of HCM City. This paper proposed a plausible solution for flood mitigation in HCM City by uplifting the Dau Tieng dam crest. This solution can be recommended based on the results of an extensive simulation study which used: (i) a statistical downscaling procedure for evaluating the climate change (CC) impacts on precipitations; (ii) the MARINE model for simulating the rainfall-runoff process; (iii) the Telemac2D model for simulating the inundation; and (iv) the GIS tool for representing the inundated areas under different CC scenarios. It was found that under the A2 scenario an increase of rainfall by 2050s and added 40% of this rainfall (assuming due to tropical depression), the maximum regulated discharges released from the Dau Tieng dam could reach 1650, 500 and 300 m 3 s À1 without any enhancement then with the dam enhancement of 1.0 and 1.5 m, respectively. As comparing to event occurred on July 21, 2009 due to the combined effect of a heavy rainfall and a high tide condition, the inner city flooding area increases by 1.2, 1.3 and 8.2% with the dam enhancement of 1.5, 1.0 m and without dam enhancement, respectively. Results of this study have therefore provided critical information for making a logical decision concerning the possibility of uplifting the height of the crest of the Dau Tieng dam to mitigate the urban flooding in HCM City under the threat of CC and sea level rise. (10.1051/lhb/2019034)
  DOI : 10.1051/lhb/2019034
• A 3D parallel boundary element method on unstructured triangular grids for fully nonlinear wave-body interactions
  
  • Dombre E.
  • Harris J.C.
  • Benoit Michel
  • Violeau D.
  • Peyrard C.
  Ocean Engineering, Elsevier, 2019, 171, pp.505-518. This paper presents the development and validation of a three-dimensional numerical wave tank devoted to studying wave-structure interaction problems. It is based on the fully nonlinear potential flow theory, here solved by a boundary element approach and using unstructured triangular meshes of the domain's boundaries. Time updating is based on a second-order explicit Taylor series expansion. The method is parallelized using the Message Passing Interface (MPI) in order to take advantage of multi-processor systems. For radiation problems, with cylindrical bodies moving in prescribed motion, the free-surface is updated with a fully Lagrangian scheme, and is able to reproduce reference results for nonlinear forces exerted on the moving body. For diffraction problems, semi-Lagrangian time-updating is used, and reproduces nonlinear effects for diffraction on monopiles. Finally, we study the nonlinear wave loads on a fixed semi-submersible structure, thereby illustrating the possibility to apply the proposed numerical model for the design of offshore structures and floaters. (10.1016/j.oceaneng.2018.09.044)
  DOI : 10.1016/j.oceaneng.2018.09.044
• Numerical schemes for the aggregation equation with pointy potentials
  
  • Fabrèges Benoît
  • Hivert Hélène
  • Le Balc’h Kévin
  • Martel Sofiane
  • Delarue François
  • Lagoutière Frédéric
  • Vauchelet Nicolas
  ESAIM: Proceedings and Surveys, EDP Sciences, 2019. The aggregation equation is a nonlocal and nonlinear conservation law commonly used to describe the collective motion of individuals interacting together. When interacting potentials are pointy, it is now well established that solutions may blow up in finite time but global in time weak measure valued solutions exist. In this paper we focus on the convergence of particle schemes and finite volume schemes towards these weak measure valued solutions of the aggregation equation. (10.1051/proc/201965384)
  DOI : 10.1051/proc/201965384
• Projet de recherche ANR SSHEAR sur les affouillements (Janvier 2015-Septembre 2019): journée publique de restitution
  
  • Chevalier Christophe
  • Larrarte Frédérique
  • Schmidt Franziska
  , 2019, pp.40p.. Les processus d'affouillement sont une cause importante de destruction des constructions (ouvrages d'art et ouvrages en terre) notamment lors des crues majeures mais leur prise en compte reste trop empirique. Depuis 2015 et pendant plus de 4 ans, le projet ANR SSHEAR pour « Sols, Structures et Hydraulique : Expertise et Recherche Appliquée » a regroupé 6 partenaires (Ifsttar, Cerema, UMR FAST, Vinci Autoroutes, SNCF réseau et IRT Railenium) dans l'objectif d'améliorer les connaissances sur les mécanismes d'affouillement et de développer de nouveaux outils d'observation et de modélisation à toutes les échelles. Pour cela, les travaux se sont articulés autour de 3 axes scientifiques et techniques : L'approche « Modèle » comportant 2 volets, expérimental et numérique, visant à améliorer la compréhension des processus d'affouillement, l'instrumentation des ouvrages réels et la modélisation numérique des phénomènes observés en laboratoire et sur le terrain. L'approche « Terrain » ayant pour objectif de développer des outils et une méthodologie pour une meilleure caractérisation et un meilleur suivi des sites vis-à-vis des processus d'affouillements. La phase finale d'« Appropriation » par les gestionnaires et praticiens ayant pour but la transmission et la valorisation des résultats du projet pour améliorer la pratique.
• Societies Facing Hydrological Extremes: The Case of Urban Supplies in France (Middle Ages to Late Eighteenth Century)
  
  • Metzger Alexis
  • Athimon Emmanuelle
  • Litzenburger Laurent
  • Giacona Florie
  • Desarthe Jérémy
  Food and History, Brepols, 2019, 17 (1), pp.23-36. Cet article s’intéresse aux événements hydrométéorologiques extrêmes sous l’angle jusqu’ici peu étudié de l’approvisionnement urbain des sociétés qui ont à y faire face. L’analyse se concentre sur des villes françaises du Moyen Âge à la fin du XVIIIe siècle. L’article montre les réactions des sociétés urbaines lors de problèmes d’approvisionnement en raison d’excès ou de déficits hydrologiques. De ce fait, il souligne que les aléas hydrométéorologiques extrêmes ont pu entraîner des soucis d’approvisionnement des villes (alimentaire, en sel, en bois, etc.), conduisant à des formes d’adaptation par les populations et les autorités urbaines au nom, notamment, de la stabilité sociale. (10.1484/J.FOOD.5.120191)
  DOI : 10.1484/J.FOOD.5.120191
• Towards a new friction model for shallow water equations through an interactive viscous layer
  
  • James François
  • Lagrée Pierre-Yves
  • Le Hoang-Minh
  • Legrand Mathilde
  ESAIM: Mathematical Modelling and Numerical Analysis, Société de Mathématiques Appliquées et Industrielles (SMAI) / EDP, 2019, 53 (1), pp.269-299. The derivation of shallow water models from Navier-Stokes equations is revisited yielding a class of two-layer shallow water models. An improved velocity profile is proposed, based on the superposition of an ideal fluid and a viscous layer inspired by the Interactive Boundary Layer interaction used in aeronautics. This leads to a new friction law which depends not only on velocity and depth but of the variations of velocity and thickness of boundary layer. The resulting system is an extended shallow water model consisting of three depth-integrated equations: the first two are mass and momentum conservation in which a slight correction on hydrostatic pressure has been made; the third one, known as von Karman equation, describes the evolution of the viscous layer. This coupled model is shown to be conditionally hyperbolic, and a Godunov-type finite volume scheme is also proposed. Several numerical examples are provided and compared to the ``Multi-Layer Saint-Venant'' model. They emphasize the ability of the model to deal with unsteady viscous effects. They illustrate also the phase-lag between friction and topography, and even recover possible reverse flows. (10.1051/m2an/2018076)
  DOI : 10.1051/m2an/2018076