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I downloaded a shapefile from OpenStreetMap that covers all ocean and coastline. This consists of around 14500 features. What I am trying to do is generate a number of bounding boxes (say 300-1000) that cover the same area as all these features. These bounding boxes can be too large, but not too small, such that extra area covered is OK but missed area is not.

The motivation for this is to extract tiles that I can serve, and the tool to extract specific tiles requires bounding boxes as input. It also accepts regions as inputs though so perhaps there is a way to go about this using regions.

I have tried to use tools like dissolve and simplify in QGIS but I am a completed beginner with GIS software and don't seem to be getting anywhere. Either the algorithm runs and nothing changes, or the software crashes.

I have attached a picture of the vector layer in QGIS.

Polygons covering ocean and coastline

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  • Dissolve should be fine, you'll end up with one feature.
    – Erik
    Commented Jul 2 at 12:41
  • Thanks for the reply. When i try and run dissolve on this it freezes as 68%. I am running on a pretty performant machine (32GB RAM and i9). Do you know if there's anything I can do to make the dissolve command more likely to succeed?
    – Michael
    Commented Jul 2 at 13:37
  • I downloaded the simplified version from OpenStreetMaps and that allowed me to dissolve. I'm not sure how I can then turn this new shape into multiple bounding boxes though.
    – Michael
    Commented Jul 2 at 14:12
  • Use the minimum bounding geometry tool with the bounding box parameter option. docs.qgis.org/3.34/en/docs/user_manual/processing_algs/qgis/…
    – GBG
    Commented Jul 2 at 14:47
  • also see gis.stackexchange.com/questions/168150/dissolve-using-gdal-ogr because if you have qgis you'll have gdal
    – nmtoken
    Commented Jul 2 at 15:02

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