Section 4 Advection Dispersion Module

4.1 Minor Enhancements and Fixes

4.1.1 Fully Specified Grid Boundary Fix

A fix has been added that addresses incorrect water level boundary assignment to the OBC_GRID type boundary. This issue only occurred when the Include Salinity and/or Include Temperature were disabled.

4.2 Mass Balance

Users can now specify an additional output type massbalance that generates a suite of csv files that report timeseries of all time-accumulated volume and mass fluxes within a model domain, as related to all simulated quantities, other than temperature. This includes tracers that do not decay or settle. Details of this output are provided in Section 2.4 of these Release Notes.

One csv file of timeseries data is generated for each simulated quantity’s mass balance, and each csv file’s headers are therefore unique. The column headers pertaining to tracers are presented and described in Table 4.1, with relevant mass units. Acronyms within column headers include:

  • V = Volumetric quantity
  • A = Areal quantity
  • MF = Mass flux
  • FV = TUFLOW FV output or computed from same
  • NS = Nodestring, encompassing WL, WLS and QN boundary types
  • WQ = Water Quality output or computed from same
  • Q = Q boundary type
  • QC = QC or QC_POLY boundary types
  • PCT = Percent

‘_N’ in the file path refers to tracer number, which increments from 1 upwards to the total number of tracers simulated. One file per tracer is produced.

Table 4.1: Tracer Mass Flux Headers
Column Header Description Units
Salinity <fvc_name>_MASSBALANCE_SALINITY.csv
TIME ISODATE Time
FV_SAL_MASS Instantaneous mass of salt computed from TUFLOW FV state variables. Always a positive quantity. tonnes
FV_MF_QC Accumulated salt fluxes across all QC and QC_POLY boundaries, summed to a single timeseries. Can be a positive or negative quantity. tonnes
FV_MF_Q Accumulated salt fluxes across all Q boundaries, summed to a single timeseries. Can be a positive or negative quantity. tonnes
FV_MF_NS Accumulated salt fluxes across all WL, WLS and QN boundaries, summed to a single timeseries. Can be a positive or negative quantity. tonnes
FV_MF_TOTAL Total of accumulated salt fluxes, with individual signs preserved. Can be a positive or negative quantity. tonnes
MF_SAL_MASS Estimate of total salt mass computed from summing previous timestep mass and current timestep mass fluxes. Always a positive quantity. tonnes
MF_PCT_ERROR The percentage error of the difference between FV_SAL_MASS and MF_SAL_MASS. Can be a positive or negative quantity. %
MF_TURNOVERS See explanatory text (Section 2.4). Always a positive quantity. No units
Temperature <fvc_name>_MASSBALANCE_TEMPERATURE.csv
Not used
Tracer <fvc_name>_MASSBALANCE_TRACER_N.csv
TIME ISODATE Time
FV_TRC_MASS Instantaneous tracer mass computed from TUFLOW FV state variables. Always a positive quantity. tonnes if TRC in in mg/L
FV_MF_QC Accumulated tracer mass fluxes across all QC and QC_POLY boundaries, summed to a single timeseries. Can be a positive or negative quantity. tonnes if TRC in in mg/L
FV_MF_Q Accumulated tracer mass fluxes across all Q boundaries, summed to a single timeseries. Can be a positive or negative quantity. tonnes if TRC in in mg/L
FV_MF_NS Accumulated tracer mass fluxes across all WL, WLS and QN boundaries, summed to a single timeseries. Can be a positive or negative quantity. tonnes if TRC in in mg/L
FV_MF_TOTAL Total of accumulated tracer mass fluxes, with individual signs preserved. Can be a positive or negative quantity. tonnes if TRC in in mg/L
MF_TRC_MASS Estimate of total tracer mass computed from summing previous timestep tracer mass and current timestep tracer mass fluxes. Always a positive quantity. tonnes if TRC in in mg/L
MF_PCT_ERROR The percentage error of the different between FV_TRC_MASS and MF_TRC_MASS. Can be a positive or negative quantity. %
MF_TURNOVERS See explanatory text (Section 2.4). Always a positive quantity. No units