Nodes represent places where actions or measurements occur in a river system, where water can be added, extracted, stored, recorded, or change ownership in a model. A node can be used to represent things that actually happen over a large physical area but that, for modelling purposes, occur at a single point. In sub-catchments, they provide a position in the catchment network where water management information can be placed. In Source, nodes are depicted using the icons shown in Figure 1.

Note: This section describes how nodes can be configured in Source. For the scientific background behind their operation, refer to the Source Scientific Reference Guide.

Figure 1. Source node icons

Bulk Licensing	Confluence	Controlled splitter	Environmental demand	Gauge	Gauge - unaccounted difference


Inflow	Inflow -unaccounted difference	Loss	Maximum Order Constraint	Minimum Flow Requirement	Off Allocation

Parallel Arcs	Scenario Transfer	Storage	Storage – unaccounted difference	Weir	Weir – unaccounted difference

Supply Point	Supply Point - groundwater extraction	Transfer Ownership	Water User	Water User – IQQM Crop Demand Model	Water User – Irrigator Demand Model

Water User – Monthly Pattern Demand Model	Water User – Pride Demand Model	Water User – Time Series Demand Model	Wetlands Hydraulic Connector

Using nodes in Source

This section outlines how to work with nodes in Source. Some actions can be duplicated for links.

Adding nodes in a model

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.

Note: Once added to a scenario, nodes can be viewed and their parameters edited using Feature Table.

About Links

Links connect nodes in Source - they link, store and route water passing between nodes. Nodes are connected using links only, and two links cannot be connected to each other without an intervening node.

A reach refers to a stretch of river, or physical section, between an upstream and downstream location. A link, on the other hand, is a logical connection within a river systems model. Routing describes the change in timing and shape of flow as water moves down a river.

Links (or reaches) can have routing configured on them. For links (or reaches) that do not have routing configured, they are used to define the order of execution in the model.

Note: Throughout this document, unless explicitly stated otherwise, the term routing means hydrologic routing, not hydraulic routing.

Links are categorised as either:

Vertical - used to connect most nodes. The first four types of links in Table 1 are all vertical; or
Horizontal (or wetland links) - used to connect the Wetlands Hydraulic Connector node (source) and the Storage node (target) only. The presence of a horizontal link at a storage node indicates that the storage is behaving as a wetland. Figure 2 shows an example of a horizontal link.

The Node Connection Matrix shows the types of links created when you connect different nodes.

Table 1. Link types in Source

Type of link	Used to connect	Representation in Schematic Editor	Example
Demand link	Supply point (source) and water user (target) nodes only	Red, dashed line
Lagged flow routing	Various nodes	Black line, with alternating dots and dashes
Storage routing	Various nodes	Black, solid line
Straight through routing	Various nodes	Black, dashed line
Wetland link (Horizontal)	Wetlands Hydraulic Connector node (source) and the Storage node (target) only	Green, solid line	Shown in Figure 2

Using links in Source

Once links have been added a model, you can edit several attributes in a similar fashion as for nodes:

Node and link default names;
Renaming nodes and links;
Configuring node and link parameters;
Adding notes to nodes and links (only for lagged flow routing and storage routing links);
Searching for nodes and links;
Deleting nodes and links;
Node and link default names; and
Copying and pasting.

Note: Once added to a scenario, links can be viewed and their parameters edited using The Feature Table.

Adding links to a model

To add a link to a model, first refer to Figure 1 which defines the terminology. To create the link:

Position the mouse cursor over the upstream node;
Click and hold on one of its downstream connectors and start dragging;
When you start dragging the mouse cursor, candidate targets are displayed (as large icons) for the upstream connector of a downstream node; and
Release the mouse and the link will ‘snap’ into place.

Figure 1. Node connection terminology

For horizontal links, the node connectors appear on the left and right side, instead of above and below the nodes. Click and drag these connectors together as described above. You can also drag the link vertically once it has been created by clicking on the red dot. This appears in the centre of the link when you click on the link.

Figure 2. Horizontal link

Dragging links

You can disconnect and reconnect a link between nodes rather than having to delete and re-add it using the Allow Link Dragged button in the Schematic Editor options toolbar. Note that not all links can be connected to all types of nodes, and specific nodes require certain links. Refer to Types of link routing for more detail.

Link elevation

You can set the elevation for a link using the Location Control window.

Note: While it is usual to use zero storage as the reference point for the elevation of a link or node, there is no convention for a link as to whether that should be at the start or end of the reach, or some point in between. Source has no mechanism for indicating the fall across a reach.

Working with Nodes and Links

Node and link default names

Whenever a node or link is created, it is given a default name in the pattern:

type #

where "type" is the type of node or link and "#" is a number which increases monotonically during the life of the schematic.

Note: The view of this name can be toggled using the Schematic Editor options toolbar.

Node connections

Nodes can be joined to each other, links between nodes will vary depending on the nodes being connected. For example, a wetland conveyance link will occur when a storage node is linked to a wetland connector.

Renaming nodes and links

Changing the name of a node or link only alters it in the scenario that you changed it in. A change in one scenario does not propagate to others; they are not linked in any way. You can change the name of a node or link using one of the following methods:

To make the Project Explorer visible, choose View » Project Explorer or click its equivalent on the toolbar. In the Project Hierarchy, click the node or link to select it, pause, and click a second time. The name will be prepared for editing (Figure 3). Type the new name and press return; or
Right-click the node or link in the schematic and choose Rename. The name will be prepared for editing. Type the new name in the field, then press Enter.

Figure 2. Renaming a node or link

Note: Source does not support duplicate names for nodes or links and will warn you if there is one. You must ensure that the names you choose are unique to the scenario.

Configuring node and link parameters

Use the feature editor of a node/link to configure its parameters, as well as edit them. Refer to About feature editors.

Note: In a catchments scenario, all nodes are, by default, confluence nodes, so every node ever created will be, at least, a confluence.

Searching for nodes and links

The Find panel allows you to search for specific nodes and links within open scenarios. Press Ctrl+F to open the Find panel (Figure 4) and enter any part of the element's name as a search term. The result set indicates the scenario containing the node/link along with its type. This is useful when you are working with very large scenarios.

Figure 3. Find panel

Copying and pasting

You can copy and paste a selection of nodes and/or links within or between scenarios in the same project. For multiple component selection, you can click and drag to draw a rectangle over the region with your mouse. Right click and choose Copy. To paste the selection, right click on the Schematic Editor and choose Paste.

The section outlines what you must be aware of when copying some parts of a scenario.

Both functions and modelled variables are copied across, but the copy must also contain any nodes that the modelled variable points to;
Copied functions will be pasted in a new folder named FromOrginatingScenarioName. This is to prevent duplicate function names by giving them a unique absolute path.
Components copied and pasted within a single scenario that have functions that reference components inside the copied selection will maintain their relative references in the new functions, with new component names. Functions that reference a component outside of the copied selection will maintain the same reference
For input sets in data sources, both the source and target scenarios can have different input sets. But, only data related to the matching input set will be copied; and
Suppose an execution order rule involves two nodes. Copying these nodes from one scenario to another will result in the rule also being copied across.

Deleting nodes and links

Deleting nodes can be achieved simply by selecting the node and pressing the delete key, or by right-clicking it and choosing Delete from the contextual menu. Deleting a link removes only the link. Deleting a node removes both the node and any links that were attached to the node.

Note: Deleting a node will cause loss of any data associated with that node, as well as any links connecting to or from it. A delete operation cannot be undone. You must recreate the link or node.

Adding notes to nodes and links

You can add a text-based message or note to a node or link. Refer to About notes for more information on notes.

Note: You can only add a note for a link that has been configured for storage routing.

To add (or edit) a note:

Open the feature editor;
Right click on the icon (of the node or link); and
Choose Add Note (or Edit Note) from the contextual menu.

Figure 5 shows how to follow this procedure for an inflow node.

Figure 4. Inflow node, adding/editing a note

Working with nodes

Individual nodes can be rotated, once they are present in the Schematic editor. First, select the node. Then, click on the green dot and rotate the node to your desired position.

Contents

About Nodes