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New to this and QGIS, and I am very lost. I need to create a choropleth crime map of number of crimes committed in the area (each borough) I have the data https://data.police.uk/data/ but when I try to join the data with the map, It just isn't working and i don't know where I'm going wrong. This photo is a example of what I intend to create:

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Here I have added the boundaries.

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Then i have mapped the dots of Crime data in the Uk, It is a month of crimes committed in each police force.

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This is just showing you what the crime data looks like.

So I'm trying to make a choropleth map with this data, but when I add it to symbology it just comes up with 000000 and when I try join the crime data to the map I don't think I'm putting the correct join field to target field.

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  • The Met Police covers more than one London borough you will need to extract by borough. first you need the borough dataset from Ordnance Survey Opendata osdatahub.os.uk/downloads/open/BoundaryLine
    – Mapperz ♦
    Feb 13 at 16:32
  • @MrXsquared I Updated it if that is more clear, Thank you!
    – Ruby
    Feb 13 at 17:06
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    you also mention 'UK' that would cover Northern Ireland - GB (Great Britain) does not include Northern Ireland.
    – Mapperz ♦
    Feb 13 at 17:41
  • @Mapperz Sorry my mistake, I meant GB.
    – Ruby
    Feb 13 at 17:46
  • As a side note it's usually not good cartographic practice to made Choropleth map with non-normalized data (ie. raw event count), this is an exemple of why handsondataviz.org/normalize-choropleth.html
    – J.R
    Oct 10 at 16:14

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If I understand correctly the numbers of commited crimes are in point-geometry and the map of the regions are polygon-geometry in a different maplayer? Then you should first join the numbers from the point-layer to the region-layer. You can join them together by location, with overlay or intersect.

Think ahead what you want when two points are in one region. SUM them up? or the Maximum value of one of both points? Or just the first come, first serve?

After the numbers are joined into the region-map, you can go to Symbology and classify the color of the region by number of crimes commited. It can go from light- to dark or just unique colours for unique numbers.

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