Let's say that green polygon is under red and part of blue with yellow stripes is also under red polygon. How can I make one polygon from every polygons that intersects my main ( red ) polygon and also remove polygons ( all green and part of blue with yellow stripes ) under red polygon?
I'm using QuantumGIS and PostGIS.
I did this (in QGIS):
- multipart to singleparts
Please tell me that I'm right ;)