2.16 Create 'doughnut' - LUPMISManual

2.16 Create ‘Doughnut’

Level of expertise required for this Chapter: Intermediate; general Map Maker training

A ‘doughnut’ - in GIS terms - is a ring-shaped polygon with an empty area inside.

1. Create the whole shape by digitizing the outer boundary of the polygon with the Polygon-tool from the toolbar left.

2.Create the ‘hole’ (island) by digitizing the inner line with the Polygon-tool.

You now have two polygons overlapping each other.

3. You extract the inner area from the larger polygon area with the Join-tool from the toolbar left. Start in the outer polygon (ring) and drag to the inner area.

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You apply the same process to any area, which is to be cut from a polygon: Join-tool, dragging from the remaining polygon to the extracted area.