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- Live: A division is described as being live if a solution for the time step can be found that satisfies both the continuity and storage equations. The general form of the continuity equation is discussed in the Ownership Mass Balance section, below (see equations 15 and 16).
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At the start of division ownership processing, the last time-step’s storage (Storage(t-1)) and each owner’s share of it (Storage(o,t-1)) are known from the flow phase routing calculations. The volume of water in a routing link division can be divided into:
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Ownership of the dead storage is shared by fixed ratio (Ratiods(o)) to all of the owners. Hence:
| Equation 4 |
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Where the sum of all the ratios is equal to one. That is:
| Equation 5 |
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Also if the maximum total dead storage specified by the modeller is StoragedsMAX then each owner’s share of this is:
| Equation 6 |
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Water is borrowed and lent between all of the owners so that the fixed ownership share given by equation (4) is always maintained.
Sharing live storage
Live storage is shared according to the owner’s share of the index flow rate (q‾(o)) (see the Proportional Routing section, below, for an explanation of this approach). The live storage calculation is done after each owner’s outflow has been determined.
| Equation 7 |
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| Equation 8 |
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Ownership of fluxes
Inflow flux
In the flow phase, the outflow flux from the division upstream becomes the inflow flux to the current division (or the outflow flux from the upstream node becomes the inflow to the division if the most upstream division in a link is being considered). The same is true for the inflow flux per owner (the ownership processing for the upstream division or node has already determined its outflow per owner).
| Equation 9 |
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| Equation 10 |
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