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I'm aiming to do a similarity analysis between a raster layer and a vector layer.

The raster layer is a 5-class ice map and the vector layer (points) contains ice jam events data. The goal here is to determine if there is a trend/pattern in the surroundings of the ice jam events that can be seen on the ice map.

I've created buffer layers around the ice jam events (50m, 100m, 500m) and I'd like to have statistics on how much of each class of the raster underneath is present within the buffer. Ex: 42% class-1, 22% class-2, 8% class-3 and so on.

I'm hoping to use QGIS/Grass GIS tools to solve this.

I'm fairly new to the software.

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You could have a look at the RasterStats plugin. It can compute histograms for zones (I don't know in what format, though), which could help you finding how much of each class is located in each zone.

There are other zonal statistics plugins (ZonalStats, Zonal statistics), but I don't think they can give accurate enough statistics for what you're trying to achieve.

  • sorry for the late reply, I had other problems with QGIS that are now solved. I tried the ZonalStats but you were right, they don't give me statistics accurate enough. Do you know to to use the RasterStats plugin? It does not seem to run for me and I can't find any tutorial or description on how to run it properly. Thanks! – Ninja Tuna Mar 18 '16 at 22:46
  • Hi, I just tried to use the RasterStats plugin and it doesn't work for me either. I posted a bug report in the plugin repo, we will have to wait the author's answer. – ArMoraer Mar 19 '16 at 14:08

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