River Inputs

Once the mesh is created, configure the simulation via input.txt (main parameters) and savefield.yaml (specific 1D/2D outputs).

`input.txt`

Mesh

Point Tolosa-sw to the Gmsh mesh file and set the bathymetry source:

mesh_name   = basic_gir_stereo.msh
bathy_in    = 0        ! 0 = flat bottom (no topography)

Numerical Scheme and Time

!--- Schemes ---
temp_scheme     = euler    ! Euler temporal scheme
spatial_scheme  = lm       ! Low-Mach spatial scheme
spatial_order   = 1
adapt_dt        = 1
cfl             = 0.5
gamma           = 0.5
alpha           = 0.5

!--- Time ---
time_format     = julian_cnes
start_date      = 24835.       ! CNES Julian day
simu_time       = 1 days

!--- Friction ---
friction_model  = 2            ! Oceanic with log-law (cb from z0)
friction_scheme = 1            ! Implicit
cb              = 0.001

!--- Coriolis ---
coriolis        = 2            ! Beta-plane

Outputs

!--- Output ---
dtw         = 600.    ! VTK/Tecplot write interval (s)
dtp         = 100.    ! Post-treatment write interval (s)
dtb         = 600.    ! Binary write interval (s)
w_tecplot   = 0
w_vtk       = 1       ! Write VTK files
w_bin       = 1       ! Write binary files
w_post      = 1       ! Write post-treatment diagnostics
verbose     = 3

`savefield.yaml`

savefield.yaml defines specific outputs beyond the full-domain fields: time series at individual points (tide gauges) and 2D fields in sub-windows.

1D Outputs — Tide Gauges

Each entry specifies a tide gauge by its mesh cell number and the write interval:

gauge:
-
  name: TIDE_G_1
  cell: 6330
  dt: 600
-
  name: TIDE_G_2
  cell: 12535
  dt: 600
-
  name: TIDE_G_3
  cell: 16717
  dt: 600
-
  name: TIDE_G_4
  cell: 13935
  dt: 600

Results are written to res/gauge/. Default variables extracted: ssh.

Available keys:

Key	Description
`name`	Output name (used as filename stem)
`cell`	Gmsh cell number
`x`, `y`	Coordinates in meters (alternative to `cell`)
`lon`, `lat`	Coordinates in degrees (alternative to `cell`)
`variables`	Fields: `ssh`, `sshuvb`, `sshuv`, `h`, etc. — `b` = bathymetry (default: `ssh`)
`dt`	Write interval (s)
`t_min`, `t_max`	Time range (default: full simulation)
`format`	Output format: `csv` (default), `plt` (Tecplot)

2D Outputs — Sub-windows

Each entry defines a spatial window and write interval:

field:
-
  name: Window_1
  x_min: -91500.
  x_max: -82000.
  y_min: -812000.
  y_max: -798000.
  dt: 360.
-
  name: Window_2
  format: bin
  x_min: -101000.
  x_max: -91500.
  y_min: -784000.
  y_max: -769000.
  dt: 360.

Window_1 uses the default VTK format; Window_2 uses binary format (readable by PyTolosa).

Available keys:

Key	Description
`name`	Output name
`x_min/x_max`, `y_min/y_max`	Window in meters (default: entire domain)
`lon_min/lon_max`, `lat_min/lat_max`	Window in degrees (alternative)
`variables`	Fields to extract (default: `sshb`)
`dt`	Write interval (s)
`t_min`, `t_max`	Time range
`format`	`vtk` (default), `bin`, `binc`

Complete Input Files

`input.txt`

!--- Mesh ---
mesh_name       = basic_gir_stereo.msh
bathy_in        = 0

!--- Schemes ---
temp_scheme     = euler
spatial_scheme  = lm
spatial_order   = 1
adapt_dt        = 1
cfl             = 0.5
gamma           = 0.5
alpha           = 0.5

!--- Time ---
time_format     = julian_cnes
start_date      = 24835.
simu_time       = 1 days

!--- Friction ---
friction_model  = 2
friction_scheme = 1
cb              = 0.001

!--- Coriolis ---
coriolis        = 2

!--- Output ---
dtw             = 600.
dtp             = 100.
dtb             = 600.
w_tecplot       = 0
w_vtk           = 1
w_bin           = 1
w_post          = 1
verbose         = 3

`savefield.yaml`

gauge:
-
  name: TIDE_G_1
  cell: 6330
  dt: 600
-
  name: TIDE_G_2
  cell: 12535
  dt: 600
-
  name: TIDE_G_3
  cell: 16717
  dt: 600
-
  name: TIDE_G_4
  cell: 13935
  dt: 600

field:
-
  name: Window_1
  x_min: -91500.
  x_max: -82000.
  y_min: -812000.
  y_max: -798000.
  dt: 360.
-
  name: Window_2
  format: bin
  x_min: -101000.
  x_max: -91500.
  y_min: -784000.
  y_max: -769000.
  dt: 360.