•To create a separate point layer that are the nodes of the network select Create node layer and click OK.


Creating Nodes


•RivEX will generate a new point layer. It will take on the name of the river network with "_nodes" as a suffix. The layer is stored as a Shapefile in the Output sub-folder in the RivEX_Workspace folder. Below is an example of the node dataset labelled by NodeID.

Nodes


•If you open attribute table of the new node layer you will see 5 fields.


The node attribute table


Field name

Description

NodeID

The unique ID given to the node

X_Coord

The X coordinate of the node

Y_Coord

The Y coordinate of the node

Valency

The number of polylines connected to the node

Node_Type

RivEX can identify up to six types of nodes and labels them with a single character code


•The definition of node types are listed below.


Code

Meaning

Definition

S

Source

A node which has no polylines flowing into it.

M

Mouth

A node which has no polylines flowing out of it.

P

Pseudo-node

A node which has 1 polyline flowing in and 1 polyline flowing out.

C

Confluence

A node which has 2 or more polylines flowing in and 1 polyline flowing out.

D

Divergence

 A node that has 1 polyline flowing in but has 2 or more polylines flow out.

B

Both confluence & divergence

A node that has 2 or more polylines flowing into it and 2 or more polylines flowing out.