AD Module

The AD module simulates the advection and dispersion of conservative constituents in the water column. It has the following features:

• Drivers are the TUFLOW FV hydrodynamic field (2D or 3D)
• 1^st and 2^nd order AD schemes
• Essentially unlimited number of AD parameters / constituents
• Option to apply decay rates
• Inclusion of heat budget and atmospheric exchange routines for detailed temperature modelling
• For the 3D module, inclusion of baroclinic effects due to variations in salinity, temperature and suspended sediment concentrations

ST Module

The ST module simulates sediment transport processes, including:

• Sediment transport in the water column through vertical mixing, horizontal advection and diffusion
• Sediment exchange with the bed through settling and re-suspension
• Tracking of multiple sediment fractions
• Morphology evolution feedback into hydrodynamics
• Special routines to simulate dredge plume generation

Morph Module

The morphological model simulates:

1. Hydrodynamic processes (currents and water level variations)
2. Sediment transport processes, including erosion and accretion
3. As erosion and accretion occurs, the base geometry of the model is updated (ie bed levels)
4. Steps 1 to 3 are repeated with the updated bed levels

At each morphological timestep in the simulation, modelled bed shear stresses and the assumed water column TSS are used to calculate the erosion/deposition rate at each point in the model domain:

• Deposition:
  
  • is the deposition rate
  • the sediment settling velocity
  • is bed shear stress
  • is the critical bed shear stress for deposition.

• Erosion:
  
  • is the erosion rate
  • is the Erosion rate constant
  • is the critical bed shear stress for erosion.

Bed level change is derived from the calculated mass deposition rates, accumulated over the timestep and converted to an equivalent volume / depth.

WQ Module

The WQ Module currently under development links TUFLOW FV with the Framework for Aquatic Biogeochemical Models (FABM).

FABM is an open source (Gnu GPL licence) code-base for the simulation of aquatic biogeochemical and ecological dynamics. It supports a common library of biogeochemical and ecological ‘components’. The underlying framework was originally developed by several European agencies and through its flexible coupling interface to hydrodynamic models has since been widely adopted within the science community and has now been applied across numerous types of aquatic systems ranging from the global ocean, to estuaries and rivers and stratified mine-pit lakes.

FABM itself supports custom model configurations and currently includes common biogeochemical configurations such as the ‘Fasham’ model template (currently the most highly cited aquatic biogeochemical model approach) and standard ‘NPZD’ model templates. It is easily customisable to simulate biogeochemical and ecological conditions as required.

The advantage of the FABM approach over other platforms is its rigorous numerical solution schemes that are known to be important in achieving accurate solutions of complex biogeochemical model equation sets.

BMT are presently beta testing the WQ Module on major commercial and research projects. For more information on its current status, please contact us.

3D Module

The 3D Module is a fully three-dimensional model that assumes a hydrostatic pressure distribution in the water column, including baroclinic terms.

When run in 3D, TUFLOW FV has the ability to simulate temperature, salinity and density stratification in order to fully resolve baroclinic (density) driven processes. Linked with this ability is a capability to accept and respond to atmospheric forcing parameters and heat transfer processes (including air temperature, relative humidity, long and short wave radiation and wind speed and direction).