Inject (force) mass in a Basin

[evetion]

As requested at the samenwerkdag 12. Instead of giving concentrations at edges, it would help debugging (especially for nodes in the middle of the network, far away from any boundaries) if we can label all discharge through a node.

The request was for a Pump, but that might be too hard (no such thing exists for Delwaq), but we could label the Basin before/after. We could re-use the BasinConcentrationState, and add a boolean to indicate that the mass can't change.

[EMMeijers]

That can be done by disrupting the delwaq pointer file at a segment with only two exchanges. Take the following steps:

• Indicate on which segment id an internal boundary should be created.
• remove all entries in the pointer (from and to) towards this segment and replace them with an boundary index. Please be aware that you increase the number of the the external boundaries by 2 (or increase the negative indices with 2).
• Add the 2 new internal boundaries in the "ribasim_bndlist.inc" file. Label them Internal
• Add a label in DELWAQ blok 5 for the newly created boundaries: ITEM 'Internal' 'Continuity' DATA 1 1
• Add the tracer Internal to the substance list.
• Add initial value for the tracer 'Internal'

Please note:

• The number of segments and exchanges do not change. Therefore the Ribasim computation can be reused!