GPU-ACCELERATED NUMERICAL SIMULATIONS OF RIVER FLOWS USING 2-D SHALLOW WATER MODEL

International audience The study of a 1D-shallow water model, obtained in a height-flow formulation, is presented. It takes viscosity into account and can be used for the flood prediction in rivers. For a linearized system, the existence and uniqueness of a global solution is proved. Finally, various numerical results are presented regarding the linear and non linear case. Nous dérivons les équations de Saint-Venant complètes avec la formulation hauteur-débit. La viscosité est prise en compte dans le modèle. Pour le système linéarisé, l’existence et l’unicité de solution globale est montrée. Des resultats numériques sont présentés aussi bien dans le cas linéaire que non linéaire.

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The instability of vertically curved fronts in a two-layer shallow water model

Physics of Fluids ◽

10.1063/5.0027831 ◽

2020 ◽

Vol 32 (12) ◽

pp. 124117

Author(s):

M. W. Harris ◽

F. J. Poulin ◽

K. G. Lamb

Keyword(s):

Shallow Water ◽

Water Model ◽

Shallow Water Model

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Modelling Weirs in Two-Dimensional Shallow Water Models

Water ◽

10.3390/w13162152 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2152

Author(s):

Gonzalo García-Alén ◽

Olalla García-Fonte ◽

Luis Cea ◽

Luís Pena ◽

Jerónimo Puertas

Keyword(s):

Experimental Data ◽

Shallow Water ◽

Shallow Water Equations ◽

Water Model ◽

Two Dimensional ◽

Shallow Water Model ◽

Experimental Dataset ◽

River Hydraulics ◽

Shallow Water Models ◽

Water Models

2D models based on the shallow water equations are widely used in river hydraulics. However, these models can present deficiencies in those cases in which their intrinsic hypotheses are not fulfilled. One of these cases is in the presence of weirs. In this work we present an experimental dataset including 194 experiments in nine different weirs. The experimental data are compared to the numerical results obtained with a 2D shallow water model in order to quantify the discrepancies that exist due to the non-fulfillment of the hydrostatic pressure hypotheses. The experimental dataset presented can be used for the validation of other modelling approaches.

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Development of a Practical Model for Predicting Soil Salinity in a Salt Marsh in the Arakawa River Estuary

Water ◽

10.3390/w13152054 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2054

Author(s):

Naoki Kuroda ◽

Katsuhide Yokoyama ◽

Tadaharu Ishikawa

Keyword(s):

Salt Marsh ◽

Hydraulic Conductivity ◽

Shallow Water ◽

Soil Salinity ◽

River Estuary ◽

Flow Simulation ◽

Design Tool ◽

Water Model ◽

Shallow Water Model ◽

Practical Model

Our group has studied the spatiotemporal variation of soil and water salinity in an artificial salt marsh along the Arakawa River estuary and developed a practical model for predicting soil salinity. The salinity of the salt marsh and the water level of a nearby channel were measured once a month for 13 consecutive months. The vertical profile of the soil salinity in the salt marsh was measured once monthly over the same period. A numerical flow simulation adopting the shallow water model faithfully reproduced the salinity variation in the salt marsh. Further, we developed a soil salinity model to estimate the soil salinity in a salt marsh in Arakawa River. The vertical distribution of the soil salinity in the salt marsh was uniform and changed at almost the same time. The hydraulic conductivity of the soil, moreover, was high. The uniform distribution of salinity and high hydraulic conductivity could be explained by the vertical and horizontal transport of salinity through channels burrowed in the soil by organisms. By combining the shallow water model and the soil salinity model, the soil salinity of the salt marsh was well reproduced. The above results suggest that a stable brackish ecotone can be created in an artificial salt marsh using our numerical model as a design tool.

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