Three-dimensional thermo-hydrodynamic modeling of stratified inland waterbodies using Telemac3D

This study focuses on a three-dimensional (3D) thermo-hydrodynamic model aimed to simulate the full dynamics of stratified freshwaters.  Based on the Navier-Stokes and energy balance equations (Grieffies, 2018), the mathematical model here considered is well suited for resolving convection and heat transfer within inland waterbodies. The solutions of the governing equations here considered are approximated numerically using a finite element scheme implemented within the Telemac3D framework (https://opentelemac.org), a well documented open-source hydrodynamic modeling software chosen for its efficiency and ability to handle complex geometries. While Telemac3D has been extensively applied to river and coastal simulations, its use in stratified saterbodies modeling is less common, highlighting the need for further validation studies regarding thermal stratification.
To evaluate the performance of Telemac3D and assess its capability of capturing convection and thermal stratification, numerical simulations of Lake Créteil (Greater Paris region, France) are conducted and compared against observational data as well as previous numerical simulations performed using Delft3D (Soulignac et al., 2017), a widely used open-source hydrodynamic modeling software (https://oss.deltares.nl/web/delft3d). Note that, given its limited size, Lake Créteil provides an ideal test case for model validation due to its comprehensive monitoring program and the thorough understanding of its hydrodynamic and thermal processes.
The presented results offer valuable insights for refining and improving thermo-hydrodynamic simulations of freshwaters in particular when using Telemac3D. Accurate modeling of thermo-hydrodynamic processes is indeed crucial for ensuring a reliable coupling with available water quality models, such as the AED2 library (https://aed.see.uwa.edu.au/research/models/AED/), already coupled with Telemac3D, which allows for the simulation of biogeochemical processes like phytoplankton dynamics and element cycling (carbon, nitrogen, and phosphorus).

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SOULIGNAC, Frédéric, et al. Performance assessment of a 3D hydrodynamic model using high temporal resolution measurements in a shallow urban lake. Environmental Modeling \& Assessment, 2017, 22: 309-322.