[Imports] UN Mappers import of UNSOS waterways in Somalia

Rafael Avila Coya ravilacoya at gmail.com
Tue Apr 7 16:14:53 UTC 2020

Hi, Christoph:

Thank you for the feedback.

My comments inline:

O 07/04/20 ás 17:45, Christoph Hormann escribiu:
> On Tuesday 07 April 2020, Rafael Avila Coya wrote:
>> Hi, Christoph:
>> What do you mean when you say that it lacks any information on the
>> provenance and specifications of the source data?
>> As explained in the wiki, I am saying that the data is coming from
>> UNSOS, using SPOT imagery. You can download the data under data
>> source site, in the Background subsection of the wiki.
> I am sorry for being unclear - i was meaning:
> * what is the meaning of the various attributes in the source data?
> Normally data sets like this come with a specification document that
> tells you what for example an attribute like FCSubtype=* or HYP=1 is
> meant to indicate.

I may ask, but bearing in mind the type of import, I think it's not very 
relevant that. I explain why:

As the import will be crowdsourced, users will decide what they import 
and how. They will not blindly upload any waterway without checking its 
validity against available imagery. They are expected to ignore (delete) 
any waterways they consider not correct, to correct the geometry and/or 
tags of the rest, if needed. This kind of import is not the first time 
it's done.

About the HYP, I've just seen that in the majority of cases 1 and 2 are 
mostly rivers checking their width, and 4 are mostly streams, so to aid 
speed the process we put those tags as default, but it's the user who 
will map, and the validators, who will decide.

> * how has this data been created from the SPOT imagery mentioned?  Was
> it produced with some kind of AI algorithm?  Was it traced by by
> humans?  If the latter was it done by people with local knowledge of
> the area or by people from abroad?  What was the original intended
> purpose of generating the data?
As far as I know, it was produced by UN personnel. I don't know exactly 
who, but some people working here do have on the ground knowledge (I do 
have some too), some others not. There are other data that has been 
collected on the ground, that will be part of the series of imports on 
> There are various peculiarities that can be observed looking at the data
> but i am reluctant to draw any conclusions or make recommendations
> based on these observations without knowing how the data was produced.
Any feedback is very welcome. Tagging is one of the fields I really 
would like to have comments/suggestions. Also the workflow, if we can 
further improve it.



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