Master configuration file

The master configuration is JSON file that provides FLUXOS with information and instructions to run a simulation. It contains pairs of variable/command names and values. The variables/commands needed to run a simulation are:

Variables/Keywords in MASTER file (JSON type)

Variable/Keyword	any useful descriptive information about the project
DEM_FILE	full path to the ESRI ASCII DEM file (.asc). Can be generated from GeoTIFF using the Python preprocessing tool (see Digital Elevation Model (DEM))
SIM_DATETIME_START	Simulation start datetime
RESTART	Restart option. If TRUE, the model will load the last output file and restart from there.
PRINT_STEP	temporal resolution of the output files (this is not the model timestep as that is defined by the Courant–Friedrichs–Lewy Condition of numerical stability)
ROUGNESS_HEIGHT	average roughness of the terrain measured in height (m), it is used in friction model and water will be retained until this height
METEO_FILE (optional)	full path to the snowmelt/rainfall timeseries
INFLOW_FILE (optional)	full pa/rainfall timeseries
EXTERNAL_MODULES => ADE_TRANSPORT => STATUS	activate 2D advection-dispersion solver
EXTERNAL_MODULES => ADE_TRANSPORT => D_COEF	dispersion coefficient

Triangular Mesh Configuration (optional)

When built with USE_TRIMESH, the following additional variables are available for configuring unstructured triangular mesh simulations:

Triangular Mesh Variables/Keywords

MESH_TYPE	Mesh type selector: "regular" (default) or "triangular"
MESH_FILE	Full path to the triangular mesh file (e.g., "domain.msh" for Gmsh format)
MESH_FORMAT	Mesh file format: "gmsh" (Gmsh .msh v2.2) or "triangle" (Triangle .node/.ele)
BOUNDARY_CONDITIONS	JSON object mapping physical group tags to boundary condition types

The JSON file supports C/C++ syntax for comments: single-line comment (//) or comment blocks (/* and */).

Example (Regular Mesh):

{
    "COMMNET": "Batch_1 - additional tests for paper",
    "DEM_FILE": "Rosa_2m.asc",
    "SIM_DATETIME_START": "2017SEP01 12:15:00",
    "RESTART": false,

    "INFLOW_FILE": {
        "FILENAME": "Flow_forcing.csv",
        "DISCHARGE_LOCATION":{
            "X_COORDINATE": 425894,
            "Y_COORDINATE": 5785553
        }
    },

    "EXTERNAL_MODULES":{
        "ADE_TRANSPORT":{
            "STATUS": true,
            "D_COEF": 0.01
        }
    },
    "METEO_FILE": "Qmelt_synthetic.fluxos",
    "OUTPUT": {
        "OUTPUT_FOLDER": "../fluxos_out",
        "PRINT_STEP": 3600,
        "H_MIN_TO_PRINT": 0.005
    },
    "ROUGNESS_HEIGHT": 0.005

}

Example (Triangular Mesh):

{
    "COMMNET": "Triangular mesh simulation",
    "DEM_FILE": "domain_dem.asc",
    "SIM_DATETIME_START": "2017SEP01 12:15:00",
    "RESTART": false,

    "MESH_TYPE": "triangular",
    "MESH_FILE": "domain.msh",
    "MESH_FORMAT": "gmsh",
    "BOUNDARY_CONDITIONS": {
        "1": {"type": "wall"},
        "2": {"type": "outflow"}
    },

    "INFLOW_FILE": {
        "FILENAME": "Flow_forcing.csv",
        "DISCHARGE_LOCATION":{
            "X_COORDINATE": 425894,
            "Y_COORDINATE": 5785553
        }
    },

    "EXTERNAL_MODULES":{
        "ADE_TRANSPORT":{
            "STATUS": true,
            "D_COEF": 0.01
        }
    },
    "METEO_FILE": "Qmelt_synthetic.fluxos",
    "OUTPUT": {
        "OUTPUT_FOLDER": "../fluxos_out",
        "PRINT_STEP": 3600,
        "H_MIN_TO_PRINT": 0.005
    },
    "ROUGNESS_HEIGHT": 0.005
}

Note

When MESH_TYPE is set to "triangular", the DEM file (DEM_FILE) is still required. If the .msh file contains non-zero vertex z-coordinates (generated by the Python preprocessing tool), the solver uses vertex elevations directly – computing cell bed elevation as the mean of its three vertex z values. Otherwise, the solver falls back to interpolating bed elevation from the DEM grid. The MESH_FILE provides the mesh topology, while boundary conditions are defined by physical group tags (mapped via BOUNDARY_CONDITIONS).

Tip: Use the Python preprocessing tool to generate both the .msh file (with embedded DEM elevations) and the modset.json config. See Digital Elevation Model (DEM) for details.