Standard practice is to place PO flow lines (see Section 3.15.1) at a minimum of several locations through the model. They are typically aligned roughly perpendicular to the flow direction. The locations should include lines just inside each of the boundaries. Other suitable locations are upstream and downstream of key structures, through structures and areas of particular interest.
The flows are graphed and conservation of mass checked (ie. the amount of water entering the model equals the amount leaving allowing for any retention of water in the model). Check that any 1D flowpaths crossed by a PO line are also included in the mass check.
In dynamic simulations, an exact match between upstream and downstream will not occur due to retention of water, however, examination of the flow lines should reflect this phenomenon.
For steady-state simulations, demonstration of reaching steady flow conditions is demonstrated when the flow entering the model equals the flow leaving the model.
See also Sections 6.3.3 and 6.4.4.
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