Edit Polygon Features

Polygon editing is for features whose shape is the data — pressure zones, parcels, footprints. It works like points and lines, with one thing to keep in mind: the boundary you close is what every later count, join, and analysis will use.

Draw a new polygon

1. Open the toolbar's "Edit" dropdown and choose the polygon layer under "Edit Layer".
2. Choose "Create Feature". The panel prompts "Click Start to begin drawing."
3. Click around the boundary to place each vertex, following the real footprint or operational edge you're capturing. While you work, the panel reports the step: "Tracing boundary and closing the polygon…"
4. Close the shape and fill in the "Attributes" — for a new "Pressure Zones" polygon, the zone number and its operational fields.
5. Click "Save changes".

When the new area borders an existing polygon, don't retrace the shared edge freehand — use snapping and the shared-border workflow so adjacent areas meet without slivers or overlaps: see Snapping and Shared Borders.

Multipart polygons

One feature can hold separate areas — a pressure zone split by False Creek, say. The panel marks these as "Multipart", so you can tell one multipart feature from several separate ones before you start reshaping.

Edit an existing polygon

1. With the layer active, choose "Edit Feature" — the panel asks you to "Select a feature to edit".
2. Click the polygon. Its saved attributes load into the panel.
3. Adjust the boundary while preserving the intended operational shape, paying closest attention to any edge shared with a neighbor.
4. "Save changes".

Zoom in on shared edges before you save. A boundary shift moves features between areas in every analysis that uses the layer, so the moment before "Save changes" is the cheap place to catch a sliver.

See Edit Sessions and Tile Rebuilds.