What you will achieve
- Draw an area containing only the intended nodes.
- Distribute and verify the assigned demand.
Step-by-step tutorial
How to allocate demand with Thiessen polygons
Define the study area, distribute a total demand, and review which nodes were included.
You can also follow the written stepsThe written steps and explanations in this chapter describe the workflow. The YouTube player loads only when you select Watch tutorial.
Before you start
- Load the network and locate demand nodes.
- Define the total demand and its unit before drawing.
01
Define the study area
Enable Thiessen and draw a closed polygon around participating nodes. The boundary does not need to cover elements intentionally left outside.
- Zoom near the boundary to avoid accidental inclusion.
- Check the node count before continuing.
02
Enter the total demand
Enter the total to distribute and run the allocation. WatDis distributes demand according to the influence areas of included nodes.
- Confirm the displayed unit.
- Keep the original total to verify the allocation.
03
Review the result
Select several nodes or open the table to compare resulting demands. The included-node values should relate to the total according to the applied method.
Do it in WatDis
- Draw a polygon leaving one control node outside.
- Allocate a known total demand.
- Verify the included set and its demands.
Common mistakes
Closing without checking nodes
A nearby boundary can include or exclude a different node than intended.
Confusing the polygon with the whole network
The tool acts on nodes inside the polygon, not necessarily every visible node.