I have 14 layers, which are polygons. They represent the channel of a river at different periods. I need to fill the gaps that exist once I overlay the polygons, but I can't change the properties of the original layers because I need to reclassify the resultant polygon on the base of the colour in order to do more analysis. I have tried to merge all 14 polygons, but the new polygon doesn't have the same properties of each individual polygon.
Do you know how I could fill the gaps between the 14 polygons?
FINAL SOLUTION:
Finally I have done it by creating two layers; one by union all layers without gaps, and other by union the layers with gaps. Then, I used Symmetrical differences tool and I obtained the layer with gap polygons.