Moving polygon to edge of boundary using QGIS

Question

I have a set of polygons that have been drawn using a set of plotted addresses.

All of these polygons fall within a geographical boundary of the local area.

As the boundary is drawn using local geography (i.e. rivers, hills etc.), rather than properties, the results look something like this:

To complete the task, there are two steps:

Firstly, bring the edges of the polygons to the border of the boundary like so:

After playing with the 'Reshape Features' tool, the end result is very messy and time consuming. I'm confident that there is no real way to automate this but I was wondering if there was a better tool that I could use to drag the polygon to the boundary line? Something that snaps to the line would be ideal.

The second step would be to connect the outlines of the polygons to 'fill in' the empty space between them, like so:

This would certainly be a manual process as I would need to contour each polygon along riverbanks etc. for a smooth finished result.

Answer 1

One approach: buffer, intersection, split with lines and manually deleting polygons:

1. buffer the polygons that you have:

2. intersect with the outline:

3. split with lines based on those pink line boundaries you have:

4. select and remove overlapping polygons:

   1. toggle editing

   2. select a polygon that is wrong:

      

   3. delete it

   4. note that some polygons are overlapping and need some special care when selecting. Also setting opacity and proper symbology helps here.

5. Done!