[Talk-ca] Mapping cut blocks in "wooded" areas

Bryan Crosby azubryan at gmail.com
Sat Mar 5 05:58:16 GMT 2011


I would tag it as natural=wood as I don’t feel that there is any distinction between a 2-year old stand and a 250 year old stand in terms of being wood, or forest.  They are merely different ages.  Licensees maintain incredibly accurate and up-to-date maps that indicate the different openings and their respective stages of development.  They have dedicated GIS guys that maintain these maps as fast as techies bring it in.  I suppose, in theory, an OSM tag could be used to indicate the stage of opening development, but one would require the date of harvesting, the date of planting and the dates of the silviculture surveys to accurately assess the phase.  Unless you are a forester you won’t have access to that information and would be guessing.   I just feel that attempting to seriously map out such temporary features accurately goes way beyond the ability of OSM (at this point, at least).

 

Bryan 

 

 

From: Samuel Longiaru [mailto:longiaru at shaw.ca] 
Sent: March-04-11 9:43 PM
To: talk-ca
Subject: Re: [Talk-ca] Mapping cut blocks in "wooded" areas

 

I very much see your point which is why I was asking for some direction.  I guess it comes down to whether the map should reflect what we see at some given snapshot in time, or whether it is reflecting the overall landuse scheme.  In short, while standing in the middle of a clear-cut, would it be more accurate that my map show that spot as wooded or not wooded?

Sam L.


-----Original Message-----
From: Bryan Crosby <azubryan at gmail.com <mailto:Bryan%20Crosby%20%3cazubryan at gmail.com%3e> >
To: 'talk-ca' <talk-ca at openstreetmap.org <mailto:'talk-ca'%20%3ctalk-ca at openstreetmap.org%3e> >
Subject: Re: [Talk-ca] Mapping cut blocks in "wooded" areas
Date: Fri, 04 Mar 2011 21:11:20 -0800

RE: cut-blocks

 

As someone who has spent done time as a forest technician, I strongly advise against mapping forestry activity.  Cut block spatial data changes daily and any images used to trace are out of date.  There are literally tens of thousands of clear cuts in British Columbia alone and there is absolutely no way OSM mappers would be able to keep up with changes.  Keep in mind that most clearcuts on crown land (and in some cases, private land) are temporary openings in various stages forest development.  A 2 year old stand is just as much a forest as a 25 year old free-to-grow stand or a 250 year old stand of timber.  I believe that mapping a privately held ‘Christmas’ tree farm would be pertinent, but these are radically different from commercial forestry openings.  

 

I would also advise extreme caution in using images to map forest development roads unless are working on a high traffic mainline.  Many spur roads are in various stages of deactivation.  It may look like a road from the outdated image, but it may have been completely deactivated and replanted.  A site inspection is the only way to be sure.  

 

Bryan

British Columbia

 

From: Daniel Begin [mailto:jfd553 at hotmail.com] 
Sent: March-04-11 8:19 PM
To: 'Samuel Longiaru'; 'talk-ca'
Subject: Re: [Talk-ca] Mapping cut blocks in "wooded" areas


 

Hi Samuel,

 

About tagging forested areas, I would use landuse=forest only if it is obvious on the field that the area is managed/harvested, as for landuse=orchard or landuse=vineyard. We have a lot of Christmas tree plantations in the area and I map them as landuse=forest because it is obvious on the imagery and on the field.  

 

If it is difficult to determine if an area is under timber lease or not, because it looks the same, I would keep it natural=wood...

 

About Cut blocks, I would map the hole they create that wooded area.  If the area is replanted, then some OSM contributor will remove the hole you map in 10-20 years from now! 

 

Mapping the reality is the best we can do and because the reality changes over time, we can keep mapping !-)

 

Daniel

 

  _____  

From: Samuel Longiaru [mailto:longiaru at shaw.ca] 
Sent: March-04-11 21:45
To: talk-ca
Subject: [Talk-ca] Mapping cut blocks in "wooded" areas


 

Hi Everybody,

I've been importing CanVec mostly south of Kamloops for the past several weeks and am going to take some time now to go back and bring stuff up to date.  One question I have though is in regards to how to treat cut blocks in the wooded areas.

I see according to the map features wiki, that the CanVec imported tag of natural=wood is technically not correct, at least for here, as wood is to be reserved only for completely reserved/unmanaged areas.  I guess most of what I have should really be mapped as landuse=forest but I have not made the change because what is under timber lease and what is not would be difficult to determine.  In one sense it's all managed to some degree or other.  But my point is rather what should be done with the cut blocks, which in some areas constitute up to 50% or more of the forested area.  http://osm.org/go/WJ1cj_R is a typical area.  It seems improper to keep them as wooded when they are clearly not, and yet most are replanted and will be wooded again someday... or at least that's what they keep telling us.

I started mapping them as it truly gives a more accurate representation of the current state of affairs on the ground... but thought I'd better get some guidance before proceeding too far.  

Thanks,

Sam L.
Kamloops 



 
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