Results 3Di
The results of a simulation are written to a NetCDF file called results_3di.nc, which follows the CF Conventions . The CF convention stipulates that the 2D and 1D mesh data are stored in separate parts of the file. The results_3di.nc file contains snapshots of values of all relevant flow variables (1D and 2D). The output timestep, i.e. the interval at which these snapshot values are written to the NetCDF file, is set at the start of the simulation.
The file size is determined by the output time step, the size of the model (number of nodes and flowlines), and the duration of the simulation.
In addition to these snap shots, 3Di can generate aggregated results. More about this can be found in Aggregated output. More about the results of the water quality can be found Water quality results 3Di
Flow results are split between node and line variables. Node variables include volumes, water levels and all the source and sink terms. Flowline variables include velocities, discharges and wet cross-section areas. A full overview is given below.
2D Mesh Cell/Node variables
First the meta information of the computational grid is defined.
Coordinates
Mesh2DFace_xcc: x-coordinate of the center of the computational cell
Name: Flow Face 2D center x coordinate
Unit: [m]
Mesh2DFace_ycc: y-coordinate of the center of the computational cell
Name: Flow Face 2D center y coordinate
Unit: [m]
Mesh2DFace_zcc: The deepest point in either the surface water cell or the groundwater cell
Name: Flow Face 2D center z coordinate
Unit: [m MSL]
Mesh2DContour_x: x-coordinates of the location of the edge of the cell
Name: List of x-coordinates forming Face
Unit: m
Mesh2DContour_y: y-coordinates of the location of the edge of the cell
Name: List of y-coordinates forming Face
Unit: m
Attributes Some administrative information
Mesh2DNode_id: IDfrom the computational core
Name: Node Identifier
Mesh2DFace_sumax: Maximum surface area in a computational cell
Name: Total cell surface
Unit: m2
Mesh2DNode_type: Type of 2D computational cell
Name: Type of 2D mesh node/face
Types: surface_water_2d, groundwater_2d, open_water_boundary_2d, groundwater_boundary_2d
Dimensions Length of the arrays
nMesh2D_nodes:
Name: Number of 2D mesh nodes/faces.
Flow Variables These are the variable that are defined in the cell centers.
Mesh2D_s1: Water level, depending on the node type, it is the surface or the groundwater level.
Name: waterlevel
Unit: m MSL
Mesh2D_vol: water volume in a cell
Name: Water volume
Unit: m3
Mesh2D_su: current wet surface area
Name: Wet surface area
Unit: m2
Mesh2D_ucx: Interpolated flow velocity in the cell center in x-direction
Name: Flow velocity in x direction in cell center
Unit: m/s
Mesh2D_ucy: Interpolated flow velocity in the cell center in y-direction
Name: Flow velocity in y direction in cell center
Unit: m/s
Mesh2D_rain: Current amount of rain in computational cell
Name: Rain
Unit: m3/s
Mesh2D_q_lat: Point discharge in computational cell
Name: Lateral discharge
Unit: m3/s
Mesh2D_infiltration_rate_simple: Current amount of infiltration in computational cell
Name: Infiltration rate
Unit: m3/s
Mesh2D_leak: Current amount of leakage in computational cell.
Name: Leakage rate
Unit: m3/s
Mesh2D_intercepted_volume: Amount of intercepted volume
Name: intercepted_volume
Unit: m3
Mesh2D_q_sss: Current amount of surface sources and sinks discharge in computational cell.
Name: Surface sources and sinks discharge
Unit: m3/s
2D Mesh Line variables
The meta information, that defines the structure for the line variables, is mentioned first.
Coordinates
Mesh2DLine_xcc:
Name: Flow line 2D center x coordinate.
Unit = m
Mesh2DLine_ycc:
Name: Flow line 2D center y coordinate.
Unit = m
Mesh2DLine_zcc:
Flow line 2D center z coordinate.
Unit = m
Attributes
Mesh2DLine_type:
Name: Type of Cell edge
Types: open_water_2d, open_water_obstacles_2d, vertical_infiltration_2d, groundwater_2d, open_water_boundary_2d, groundwater_boundary_2d
Dimensions
nMesh2D_lines:
Name: Number of 2D Mesh lines.
Flow variables
Mesh2D_u1: This variable, in case of Horton-based infiltration and groundwater flow, also consists of the vertical flow and the groundwater flow. This depends on the Line Type. This also yields for most of the other line variables.
Name: Flow velocity on 2D flow line
Unit: m/s
Mesh2D_q:
Name: Discharge on flow line
Unit: m3/s
Mesh2D_au:
Name: Wet cross-sectional area
Unit: m2
Mesh2D_up1:
Name: Flow velocity in interflow layer
Unit: m/s
Mesh2D_qp:
Name: Discharge in interflow layer
Unit: m3/s
1D Mesh Node variables
The results for the 1D variables are structured in a similar way. Note that embedded nodes do not have a 1D water level, volume etc information. This information can be found in the 2D results.
Coordinates
Mesh1DNode_xcc:
Name: Node 1D x coordinate
Unit: m
Mesh1DNode_ycc:
Name: Node 1D y coordinate
Unit: m
Mesh1DNode_zcc:
Name: Node 1D z coordinate
Unit: m MSL
Attributes
Mesh1DNode_id:
Name: Node Identifier
Mesh1DNode_sumax:
Name: Total cell surface
Unit: m2
Mesh1DNode_type:
Types = node_without_storage_1d, open_water_with_storage_1d, open_water_boundary_1d
Dimensions
nMesh1D_nodes:
Name: Number of 1D mesh nodes
Node variables
Mesh1D_s1: Waterlevel in 1D Node
Name: Waterlevel
Unit: m MSL
Mesh1D_vol: Water Volume in a cell
Name: Water volume
Unit: m3
Mesh1D_su: Current wet surface area
Name: Wet surface of 1D Node
Unit: m2
Mesh1D_rain: Inflow in 1D from rain or dry wetter discharge
Name: Inflow in 1D from rain
Unit = m3/s
Mesh1D_q_lat: Point source/sink flux in 1D cell
Name: Lateral discharge in/from 1D cell
Unit = m3/s
1D Mesh Line variables
Coordinates
Mesh1DLine_xcc:
Name: Flow line 1D x center coordinate
Unit: m
Mesh1DLine_ycc:
Name: Flow line 1D center y coordinate
Unit: m
Mesh1DLine_zcc:
Name: Flow line 1D z center coordinate
Unit = m MSL
Attributes
Mesh1DLine_id:
Name: Line identifier
Mesh1DLine_type:
Types: embedded_1d, isolated_1d, connected_1d, long_crested_structure_1d, short_crested_structure_1d, double_connected_1d, from_node_with_storage_1d2d, from_node_without_storage_1d2d, potential_breach_1d2d, groundwater_1d2d, boundary_1d
Dimensions
nMesh1D_lines:
Name: Number of 1D Mesh lines
Flow variables
Mesh1D_u1:Flow velocity on 1D flow line, including 1D2D connections.
Name: Flow velocity on 1D flow line
Unit: m/s
Mesh1D_q:
Name: Discharge on 1D flow line
Unit: m3/s
Mesh1D_au:
Name: Wet cross-sectional area
Unit: m
Mesh1D_breach_depth:
Name: Breach depth on 1D2D connection
Unit: m
Mesh1D_breach_width:
Name: Breach width on 1D2D connection
Unit: m
Pump variables
Coordinates
Mesh1DPump_xcc:
Name: Start point Pump 1D x-coordinate
Unit: m
Mesh1DPump_ycc:
Name: Start point Pump 1D y-coordinate
Unit: m
Attributes
Mesh1DPump_id:
Name: Pump identifier
Dimensions
nPumps:
Name: Number of 1D pumps
Flow variables
Mesh1D_q_pump:
Name: Pump discharge
Unit: m3/s