Version 3.1.0

In BASEMENT Version 3.1 the bed load transport has been extensively revised and supplemented (e.g. slope collapse). The new features include the transport of passive scalars and additional output variables (e.g. transport capacity or bed shear stress). In general, extensive bug fixes were made and the documentation was revised.

General

• The console output displays now show the most recent output of the programs by default.
• Pressing Ctrl+C now aborts the simulation after the current time step.
• Implementation of the bedload transport capacity as output variables (trsp_capacity and trsp_capacity_abs).
• Implementation of Smart & Jaeggi (1983) bedload transport formula.
• Implementation of the LINKED morphology boundary condition *equilibrium_linked*.
• Implementation of the LINKED hydraulic boundary condition *zhydrograph_linked_kinE*.
  
• Implementation of max. bed shear stress as tracking variable (via FLOOD in model.json).
• Implementation of passive scalar transport by advection.
  
• Implementation of gravitational transport (e.g. bank collapse) due to the local bed slope exceeding a critical angle.
• An improved method for the local bed gradient calculation has been implemented. The newly implemented method secondary_mesh calculates the bed gradient based on (i) the bed elevation of the neighbouring cells in case of 3 neighbouring cells, (ii) the bed elevation of the two neighbouring cells and the cell itself in case of 2 neighbouring elements or (iii) the bed elevation of the neighbouring cell and the cell itself in case of one neighbouring element. The improved method is used by default, while the previous method (area_weighted) is still available but not recommended. The method for the bed gradient calculation can be selected unter SETUP/DOMAIN/BASEPLANE/MORPHOLOGY/PARAMETERS/bed_gradient_type. The bed gradient has an influence on the bedload transport direction if the block LATERAL_SLOPE is activated and on the threshold of incipient motion for bedload transport if the block INCIPIENT_MOTION is activated. In addition, the bed gradient is now available as an output variable under the name bed_gradientin the simulation.json (only if at least one the above mentioned blocks is activated).
• The local bed gradient is available as output variable under the names bed_gradientin the simulation.json (only if the INCIPIENT_MOTION or LATERAL_SLOPE blocks are activated).
• Splitting the bedload transport flux in an advective part (same direction as flow direction) and a diffusive part (due to bedload direction correction from lateral transport and curvature). The advective part is solved with the existing HLLC solver, while an upwind scheme is applied for the diffusive flux. This makes the solver more stable when using bedload transport direction correction due to local slope or curvature.
• An improved method for the local velocity gradient calculation has been implemented. The newly implemented method calculates the velocity gradient based on (i) the velocity of the neighbouring cells in case of 3 neighbouring cells, (ii) the velocity of the two neighbouring cells and the cell itself in case of 2 neighbouring elements or (iii) the velocity of the neighbouring cell and the cell itself in case of one neighbouring element. The new method replaces the previous calculation method.
• 2dm-mesh files are now supported as input for the fixed bed elevation. The topology of the fixed bed mesh must be identical with that of the computational mesh and must only differ in the elevation information.
• The documentation has be revised and updated.
  

Bug Fixes

• Xdmf output files that are created using the UI now reference the auxiliary results file using a relative file path.
• A Bug in the bedload transport flux calculation has been fixed. The bug resulted in an asymmetrical behavior depending on the orientation of the flux vector with respect to the edge normal.
• The parameter max_time_step is now taken into account in the computation of the integration time step.
• The missing file browser for the ‘hqrelation_file’ tag of the STANDARD hydraulic boundary condition ‘hqrelation_out’ has been added.
• During the calculation of the uniform flow depth in the uniform_out boundary condition, incorrect cell dimensions might have been used. This problem has been fixed.
• For elements which (1) did not belong to any of the regions from GEOMETRY/REGIONDEF or (2) for elements whose region was not listed under HYDRAULIC/FRICTION/regions, the default_friction value should have be used. However, this has not been the case. Instead, for case (1) an “out of range” error occurred, while for case (2) a friction value of 0.0 has been used. With the fix, the default_friction value is used in both cases (1) and (2).
• In the case of “region_defined” initial conditions, the initial water surface elevation and the specific fluxes in x- and y-direction were set to 0.0 for elements which did not belong to any of the regions in GEOMETRY/REGIONDEF. With the bugfix, the initial conditions for cells which do not belong to any regions or whose region is not listed under HYDRAULIC/INITIAL/regions “dry” initial conditions are set and the user is informed with a warning.
• A bug in the calculation of the lateral transport direction (MORPHOLOGY/BEDLOAD/DIRECTION has been fixed. The bug led to an underestimation of the lateral transport. Further, a more general approach has been implemented for the influence of lateral bed
  slopes on the bedload transport direction. The block IKEDA has been renamed to LATERAL_SLOPE.
• An inconsistency in the setup resulted in the approach of Van Rijn (1989) being chosen automatically when the INCIPIENT_MOTION block was activated.
• Mathematical operations of incorrect precision (single/double precision) were used by the kernels.
• The non-dimensional bed shear stress and the critical non-dimensional bed shear stress are now available as output variables under the names theta and theta_critical in the simulation.json (only if the MORPHOLOGY block is activated).
  

Known Issues

• Model setup fails if there is a dot ‘.’ in the working directory path. For example: “MySimulations/Sim1.1/" does not work, while “MySimulations/Sim1_1/” works.

Note: Existing installations of BASEMENT version 3.0.1 (or earlier) are not automatically detected by the updated installer. Therefore uninstall any previous version of BASEMENT e.g. using the link in the Start Menu before installing the newest version.