Geospatial · Build and fix geometry

Dissolve

Merges shapes into one, or one per group, so the inner borders disappear. For example, county outlines into one outline per state. To keep totals alongside the shapes, use Aggregate's Union (dissolve).

Also known as: Merge polygons, union

How it works

With Group by empty the whole layer is unioned into a single feature; with one or more key columns you get one feature per distinct key combination. Then pick the Geometry column to merge. The output has the key columns and the merged geometry under the input column's name; every other column is dropped, because there is no single row to take it from. Pick the geometry column itself as a key and it is ignored. To keep totals such as population next to each merged shape, use Aggregate with Union (dissolve) and Sum in one step instead.

Inputs and outputs

Settings

{
  geometryColumn: string
  groupBy: string[]
}

Example

County polygons into one outline per state: group by state, geometry column geom. The result has two columns, state and geom.

More in Build and fix geometry

• Make Point — Turns longitude and latitude columns into points you can map and use in other spatial nodes.
• Poly Build — Connects ordered points into a line or polygon, or wraps them in a hull or bounding box, optionally one shape per group. For example, GPS points into route lines.
• Make Valid — Repairs broken shapes, such as self-crossing polygons, so later spatial steps don't fail on them.
• Reproject — Converts geometry from one coordinate system to another. Use it before measuring or overlaying layers that come in different projections.
• Poly Split — Breaks multi-part shapes into single parts, one row per part, such as the islands of a country.
• Remove Holes — Fills in the holes inside polygons, keeping only the outer boundary.