Mass Balance

The Mass Balance tool allows the user to evaluate the total model’s water volume as well as determine the mass fluxes through each boundary. Mass balance is calculated based on model output snapshots written to the EE_BC.OUT file. The smaller the output snapshot interval the more accurate the reported results will be. An example of mass balance for a model of the Caloosahatchee Estuary is shown in Figure 1. It should be noted that conservative constituents, such as water, salinity, and dye will be reported accurately. However, for non-conservative constituents, the tool only provides approximate loadings. This is because the kinetic, atmospheric, and bottom processes are not accounted for. Surface and bed boundaries are ignored in the calculations, so values for temperature, sediment, and water quality should be regarded with caution. 

Figure 1. Mass Balance Window.

Mass balance through each boundary group and the whole domain is calculated and reported as statistics as shown in Figure 2 below.

Figure 2. Mass Balance report.

View the mass balance through each boundary group time series by checking the Show Time Series Plot checkbox in Figure 1. This will produce a plot similar to that shown in Figure 3 below.

Figure 3. Mass Balance time series plot.