Nodes and Links

Nodes

The following nodes are available in MUSIC X. 

Broadly, these nodes can be divided into 3 categories; Source Node, Treatment Nodes and Other Nodes.

To add a node to a model, either:

• Drag the appropriate type of node from the Node Palette and drop it onto the Schematic Editor; or
• Right-click on the Schematic Editor and choose the appropriate node from the Add menu.

Source Node

Source node can be created as other nodes as detailed above. Once you select a Source Node, you will be presented with a series of dialogue boxes, which allow you to specify the characteristics of the source node. You can define the Land Use/Zoning. You can then edit for the proportion of impervious area, the soil properties, and the baseflow and stormflow pollutant concentrations for TSS, TP and TN. 

Refer to Editing Source Node Properties for an example of the dialog boxes to configure a Source node. The only difference between the different Land Use/Zoning of source nodes is the default pollutant concentrations. 

Treatment Nodes

To create a Treatment Node, select the specific Treatment Node from Node palette and drop it onto the schematic editor.

Once you select a Treatment Node, you will be presented with a series of dialogue boxes which allow you to specify the characteristics of the particular treatment node. At any time, these dialogue boxes can be recalled to modify the treatment node’s characteristics, by right-clicking on the selected node, and choosing Edit Properties. Please refer to Creating a Stormwater Treatment Train for further details.

Other Nodes

A Junction Node simply allows two upstream tributaries to be merged. It provides no treatment, and directly passes through any flow or water quality characteristics to the next downstream node.

The Receiving Node is used to specify the discharge point of the catchment being modelled, and again, performs no operations on flow or water quality received by it.

The Pre and Post-Development Nodes are not available in MUSIC X. However, you can create more than one receiving node and compare the results as required. 

Drainage Link

The Drainage Link, as its name implies, links flows from one node to the next downstream node.

To create a a drainage link between two nodes: 

1. Hover your mouse over the start node until you see a green target symbol.       
2. Left click and move your mouse to the end node for the link.

The first line you created will be the Primary drainage link. If you create another drainage line from the same node going to some other nodes, that will be created as Secondary drainage link.

Editing Drainage Link Properties describes the available drainage link properties in more detail, including the provision to specify flow-routing properties at each drainage link.

'Secondary' drainage links are optional. Secondary links are only required if you want to take advantage of the split flow functionality provided by MUSIC X, which is discussed next.

Split flows

MUSIC X incorporates a facility to allow outflow components from source and treatment nodes to be routed via different flow pathways. This allows, for example, the routing of surface flows and groundwater/infiltrated flows via different treatment pathways.

If you setup a MUSIC X project with just 'Primary' drainage links, MUSIC will automatically route all default outflow components to the next downstream node (as defined by the 'Primary' drainage link). If you wish to route any default or other non-default outflow components via an alternate pathway, it will be necessary to use 'Secondary' drainage links.

'Secondary' drainage links can be created in much the same way as 'Primary' drainage links. However, there are a few rules that must be adhered to:

• Secondary drainage links can only be created from Source and Treatment node types.
• You must specify a primary outflow link and at least one inflow link before you can add a secondary drainage link from a node. Only one primary outflow link can be added for each node but multiple secondary outflow links can be added to each node. Specifically, the number of outflow links is limited to the number of outflow components for a particular note. For example, if a node has five different outflow components, then a maximum of five outflow links can be created (i.e., one outflow component per link).
• The arrangement of drainage links must not create any "closed drainage loops" (an error message will be displayed if this occurs).
• Once you create a secondary drainage link, you can edit the link . The properties dialog allow you to select which outflow component you would like to associate with that link (as shown below). More than one secondary outflow link can be added to each node (up to the limit mentioned above) and more than one outflow component can be assigned to each link, if desired.

• You will not be able to switch off any of the default flow components from the primary drainage links (e.g., pipe flow, weir flow etc). This ensures that all default flow components are always routed downstream (so water does not disappear!). You will not be able switch on any of the non-default outflow components via the primary drainage links (e.g., infiltration, reuse, ET etc). These non-default flow components can only be added via the secondary drainage links.
• Any of the available flow components can be added and removed via secondary drainage links. MUSIC will ensure that only one flow component is shared between all outflow links for a particular node. So, for example, if you add "Pipe flow" to a secondary link it will be removed from the primary drainage link.

Creating nodes and links

There are a few simple rules which you should be aware of in creating nodes and links within MUSIC:

• Source nodes must be between 0.001ha and 10,000ha (ideally the lower limit of source node area should be 1ha).
• Realistic bounds on size and other design parameters are also specified for treatment nodes.