# Sediment Transport and Morphological Change¶

NUMERICAL SCHEME

• Sed_Scheme: numerical scheme for solving the advection-diffusion equation
• Sed_Scheme = TVD: TVD scheme
• Sed_Scheme = Upwinding: Upwinding scheme (defalt)

SEDIMENT PARAMETERS

• D50: median grain diameter $$D_{50}$$, defalt $$D_{50} = 0.5mm$$
• Sdensity: gravity of sediment $$s$$, defalt $$s = 2.68$$
• n_porosity: porosity of sediment $$n$$, defalt $$n=0.47$$
• WS: settling velocity $$w_f$$, defalt $$w_f = 0.125$$ m/s
• Shields_cr: critical Shields parameter for suspended load $$\theta_{cr}$$, defalt $$\theta_{cr} = 0.05$$
• Shields_cr_bedload: Shields parameter for bedload $$\theta_{cr}^{b}$$, defalt $$\theta_{cr}^{b} = 0.047$$ based on Meyer-Peter and Muller (1984)
• Kappa1: Runge-Kutta parameter $$\kappa_1$$, defalt $$\kappa_1 = 0.3333$$, 4th-order
• Kappa2: Runge-Kutta parameter $$\kappa_2$$, defalt $$\kappa_1 = 1.0$$, 4th-order
• MinDepthPickup: the minimum depth for sediment pickup action. The purpose of this parameter is to avoid over-shooting at a very small depth. Default: MinDepthPickup = 0.1m.

MORPHOLOGICAL CHANGE

• Bed_Change: logical parameter, T: update depth, F: no bed change.
• Hard_bottom: logical parameter, T: hard bed, no erosion allowed, F: sediment bed
• Hard_bottom_file: the file contains the distribution of hard bed points (0:hard bed, 1: sediment bed). The format is the same as the depth file
• Morph_step: ratio of Boussinesq model time step to the morphological updating step, $$dt_{morph}$$, defalt: $$dt_{morph}$$ = 25

AVALANCHE

• Avalanche: logical parameter, T: consider avalanche, F: not consider avalanche
• Tan_phi: tangent of the repose angle $$\tan \phi$$, defalt $$\tan \phi = 0.7$$, or 35 deg

OUTPUT

• PLOT_INTV_SEDIMENT: time interval for plotting sediment transport variables, defalt is the same as the Boussinesq model
• C_xxxxx: Sediment concentration (g/l) at xxxxx output step
• Pick_xxxxx: sediment pickup value at xxxxx output step
• Depo_xxxxx: sediment deposition value at xxxxx output step
• DchgS_xxxxx: depth change (without considering porosity ) due to suspended load UPTO xxxxx output step
• DchgB_xxxxx: depth change (without considering porosity ) due to bedload UPTO xxxxx output step
• BedFx_xxxxx: bedload flux in x
• BedFy_xxxxx: bedload flux in y
• dep_xxxxx: depth (with considering porosity) UPTO xxxxx output step