Is it possible to have a diffuse transition between two polygons?

Question

(QGIS) I'm working on a habitat map. The aim is to map the different habitats in an area in order to produce a map. The habitats are identified by polygons. But sometimes habitats are gradually replaced by others on site. So I'm looking for a way of blending certain polygons together. Let's say that A and B are my two habitats, shown in Red and Blue. Is it possible for me to have a diffuse boundary between the Red and Blue polygons? I should point out that this request is purely aesthetic for the purposes of producing a final map. An unorthodox solution would work completely.

Answer 1

Note that you'll get better result by exporting your map and get the aesthetic right with a graphic software. That being said it could be done.

To do it solely in QGIS I would convert the border between the two habitat to a polyline and style this line using the Lineburst Symbol layer type.

This solution won't be perfect :

• the end of the line will look bad (the wider the line the worse it will look),
• as Lineburst style is just color on top of your habitat polygon it will only work if you style your habitat with simple fill and no transparency

Below an example on how it looks, the top part of the border is intentionally left without line to better show the effect.

Another way would be to draw a polygon overlapping the border and style it with stripe of the two habitat color. This is not really blending but it will convey the transition status of the zone...