Talk:PoliMappers/mapping deforestation

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Map what you know

A good guide is to only map what you know, if you don't know - leave the map blank. Colouring in the map may look pretty, but it may hide errors that would be best left for others to find having been altered to the area by the blank area. Warin61 (talk) 00:09, 14 March 2019 (UTC)

I think that with the propose of mapping deforestation if we add data in this area were the data aren’t present we don’t just coloured the map but we can create a good database, from which is possible to analyse the evolution of the forest area and have the possibility to study better some aspect of climate change. LorenzoStucchi (talk) 09:10, 16 March 2019 (CET)


NO! This fails to map what is there. Map the surrounding area with what you can see and leave a hole in it, use a relation to do it of the type=multipolygon.Warin61 (talk) 00:09, 14 March 2019 (UTC)

I’m not agree because If we leave a empty area this can be everything that doesn’t have a tag, for example grass land where we are not sure if its grass or meadow, that its hard to distinguish it from the satellite.LorenzoStucchi (talk) 09:10, 16 March 2019 (CET)


Don't think so. Too general. And the text links it to are 3 land uses, these are not land covers.Warin61 (talk) 00:09, 14 March 2019 (UTC)

I agree with you that this can be too general, exactly there are 3 different tag to tag the area if better quality imagery is available and is possible to distinguish between them. The idea is to have a more general tag that can be future improved with local knowledge. LorenzoStucchi (talk) 09:10, 16 March 2019 (CET)


This is not a land cover, it is a land use. And OSM presently prefers a more detailed value.Warin61 (talk) 00:09, 14 March 2019 (UTC)

I think that this is landcover, also for the reason explained in the introduction and considering the previous scientific studies.LorenzoStucchi (talk) 09:10, 16 March 2019 (CET)


This at least works .. it is a land cover and it does have trees. Unfortunately it does not render on many maps, so you might also tag it natural=wood. Warin61 (talk) 00:09, 14 March 2019 (UTC)

Depends what we think that is more interesting the info in the database or the rendering of the map. LorenzoStucchi (talk) 09:10, 16 March 2019 (CET)

For deforestation there needs to be a comparison of the past and the present.

Deforestation means an area where there were trees that have been converted to something else. OSM does not map change, it tries to map what is there. Certainly you can use OSM to map the presence of trees. For the past OSM is not suitable. For the past mapping there is OHM - open historical map . That will require some older satellite imagery to map what was there then, together with the date of the imagery. If there is satellite imagery of various dates that also can go in OHM. Warin61 (talk) 04:08, 14 March 2019 (UTC)

Sorry I didn't see before this comments, but I give answer in the mailing list. Thanks also for your ideas. LorenzoStucchi (talk) 22:49, 15 March 2019 (CET)
The information about the past is inside the history of the elements so this information is inside the database. I also reply to all the point here and not just in the mailing list. LorenzoStucchi (talk) 22:49, 15 March 2019 (CET)