[Qgis-user] Request for Guidance on Using 'Dissolve' Tool in QGIS with IUCN Data

[Marcello Bilancioni]

Good morning,

I am currently working with the mammal species distribution data provided
by IUCN, and analyzing these shape files in QGIS.

As part of my analysis, I have been using the 'Dissolve' tool in QGIS to
merge rows of the same species into a single entry. This operation is aimed
at creating a single comprehensive polygon that represents each species'
entire distribution range. However, while the tool successfully
consolidates the geometries, it looses important attribute data from the
original attribute table. In particular, this leads to the loss of valuable
information within the "Presence" and "Origin" columns, where the values
can differ across entries for the same species.

Could you provide any recommendations on how to avoid such data loss? Is
there a strategy or method that could effectively summarize or retain this
varied information while processing the data using the 'Dissolve' tool?

Furthermore, in my dataset, I have noticed some specific values under the
"Presence" and "Origin" columns: "presence 3", "presence 6", and "origin 5"
(I have attached a list with those species here). According to the IUCN
guidelines, these values need to be updated or adjusted. Do you happen to
know how to update these entries within QGIS best?

Thank you in advance for any assistance you can provide.

Best regards,

Marcello Bilancioni
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20230626/ccf3bff0/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: mammal_list.xlsx
Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Size: 5524 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20230626/ccf3bff0/attachment.xlsx>