Le H. A., Lambrechts J., Ortleb S., Gratiot Nicolas, Deleersnijder E., Soares-Frazao S. (2020). An implicit wetting-drying algorithm for the discontinuous Galerkin method : application to the Tonle Sap, Mekong River Basin. Environmental Fluid Mechanics, 20 (4), p. 923-951. ISSN 1567-7419.
Titre du document
An implicit wetting-drying algorithm for the discontinuous Galerkin method : application to the Tonle Sap, Mekong River Basin
Le H. A., Lambrechts J., Ortleb S., Gratiot Nicolas, Deleersnijder E., Soares-Frazao S.
Source
Environmental Fluid Mechanics, 2020,
20 (4), p. 923-951 ISSN 1567-7419
The accurate simulation of wetting-drying processes in floodplains and coastal zones is a challenge for hydrodynamic modelling, especially for long time simulations. Indeed, dedicated numerical procedures are generally time-consuming, instabilities can occur at the wet/dry front, rapid transition of wet/dry interface and mass conservation are not always ensured. We present the extension of an existing wetting-drying algorithm in two space dimensions and its application to a real case. The wetting-drying algorithm is implemented in Second-generation Louvain-la-Neuve Ice-ocean Model (), a discontinuous Galerkin finite element model solving the shallow water equations in a fully implicit way. This algorithm consists in applying a threshold value of fluid depth for a thin layer and a blending parameter in order to guarantee positive values of the water depth, while preserving local mass conservation and the well balanced property at wet/dry interfaces. The technique is first validated against standard analytical test cases (Balzano 1, Balzano 3 and Thacker test cases) and is subsquently applied in a realistic domain, the Tonle Sap Lake in the Mekong River Basin, where the water level can vary by about 10 m between the dry and the wet season.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Hydrologie [062]
