project modelling

The relationships between flow, sediment transport, morphological change and the resultant subsurface sedimentology are quantified using an established 3D morphodynamic modelling approach (Delft3D). We are using the newly-released open-source code and add-in new code for:

  1. an improved treatment of spatial and temporal heterogeneity in bedform roughness
  2. an enhanced prediction of the role of vegetation as a control on sediment deposition and bar stabilisation

These modifications are made in collaboration with Project Partners Deltares. The first stage of modelling the Columbia River Estuary is with a fixed bed using NOAA MBES survey data. The second stage is to allow the bed to evolve. The modelling mesh is in three domains and stretches beyond the river exit into the ocean.

Example Output

Model output from the Paraná River in Argentina.

The three modelling domains used for the TIFZ of the Columbia River

The model will be applied to a reach from Port Westward (formerly Beaver Army Terminal) to Tongue Point, where boundary conditions are gauged. Simulations will be conducted to quantify the relationships between flow, sediment transport, morphological change and sedimentology at three distinct timescales:

  • (T1) over 28 day periods associated with individual field seasons and a full tidal cycle
  • (T2) over the two years covered by the project data collection
  • (T3) over the period from the first reliable bathymetric surveys (1935) to the present day.

Model runs will be validated against field data and historic surveys.