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I am fairly new to QGIS and I am doing a masters degree.

I have a number of GPS coordinates which represent the location of elephant sightings. I need to find out what habitat type each of these coordinates was recorded in (e.g. scrubland, grassland, forest). To do this I have been trying to use the World Terrestrial Ecosystems map from Esri Landscape (https://www.arcgis.com/home/item.html?id=d9434e94c817434c8448445501aee60a) which is a world map showing many different habitat types.

I have loaded the map into QGIS alongside my GPS coordinates (which can be seen in the attached screenshot)

Habitat map with GPS coordinates overlain

but i am unsure about how to assign each of these coordinates a habitat type based on the underlying map. I have tried using a point sampling tool which i have used for previous analysis but it just produces a blank csv file with no results.

How could I tackle this?

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    More information please on what you're trying to do. Screenshots would help. So would a sample of your data and a link to the World Terrestrial Ecosystems map.
    – Pointdump
    May 14, 2022 at 18:40
  • As per the help center please do not include chit chat like thanks in your posts.
    – PolyGeo ♦
    May 15, 2022 at 21:50

2 Answers 2

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Use QGIS expressions with the function raster_value(). Be aware: both layers have to be in the same CRS:

 raster_value( 'raster', 1, $geometry)
  • raster is the name of your raster layer.
  • 1 is the number of the band.
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    Adding to @Babel's amswer, for instance you could edit your point (observations) layer's settings and add a virtual field (Field calculator in the Fields tab) with the expression he provides. This virtual field would then tell you the veg type at each observation point.
    – Houska
    May 15, 2022 at 13:29
  • Thanks for the suggestion, I tried this and the results it produced were blank. I’ve had this issue with all the things I’ve tried and think maybe something is wrong with the map itself?
    – JoshB
    May 16, 2022 at 7:24
  • Whatbkind of data you have, hiw are your layers saved? Do you have them saved as local files?
    – Babel
    May 16, 2022 at 8:16
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You can use the processing tool Sample raster values:

"Extracts raster values at the point locations. "

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  • Thanks for the suggestion, I tried this and the results it produced were blank. I’ve had this issue with all the things I’ve tried and think maybe something is wrong with the map itself?
    – JoshB
    May 16, 2022 at 7:24
  • The problem is probably that the layer is a service. You need to download the raster if it is available.
    – BERA
    May 16, 2022 at 18:25

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