For an introduction to links, see Nodes and Links.
Source supports three types of link routing - straight through routing (default), a lagged routing model or a Storage routing model. You are responsible for ensuring that you use the correct model for each link.
Note that you can configure constituents, ownership and ordering for a storage routing link only.
To change the link routing type:
You can check which routing models are in use in a scenario using the Project Hierarchy. The example inshows that there are two types of links in use - lagged flow and storage routing.
All links are assigned straight through routing by default and have the following features:
Lagged flow routing only considers the average travel time of water in a river reach. It does not consider flow attenuation. The flow entering a link exits at some whole number of time-steps in the future.
Figure 4 shows the feature editor for a lagged flow routing link and Table 2 lists the associated parameters.
This represents the time it takes for water to travel along the link and is a positive real number. If the specified lag time is not an integer multiple of the model time-step, it will be rounded to the nearest time-step.
|Initial Storage||Volume||The amount of water deemed to be in the link on the first time-step. For example, if there is a lag of two days, and there is 10ML in the link at the start of the run, then 5ML is deemed to be flowing out each day (total initial storage divided by lag).|
A link configured for lagged flow routing is treated as a series of sub-reaches or 'divisions' of equal length, with the travel time in each division equal to one time-step. Water moves through the link progressively, without attenuation. You cannot configure fluxes, constituents or ownership on a lagged flow routing link. If lateral flows are significant and/or there is dead storage in the reach, you can model lagged flow routing using storage routing and the generalised non-linear storage option, as follows: