[Talk-GB] Mapping of Kielder Forest(s)

[Nick]

Hi Russ and James

A forest is and has always been more than just trees, so designations 
become even more complex when the land use is mixed e.g. agro-forestry. 
The point about mapping is surely that there are multiple uses that maps 
are put to. So for example, it could be used for estimating biomass in 
which case species, age, percentage tree cover etc. are important data 
sources. If we map large areas the assumption is that it is uniform 
unless additional data (tags) indicate otherwise. Conversely if small 
areas are mapped (sub compartment approach) but lacks precision and 
accuracy, then any subsequent analysis could be flawed. The point I am 
trying to make is that what and how we map affects the usefulness of the 
maps for a wide range of users - the more detail, the more potential 
benefit. Therefore micro-mapping to my mind has more potential benefit 
than coarse-mapping but also depends on the additional linked data 
provided.

Cheers

Nick

On 02/09/2021 14:26, Russ Garrett via Talk-GB wrote:
> We clearly don't have a consensus here, so I will concede defeat. I've
> reverted all my changesets which have touched Kielder forest.
>
> Unfortunately I don't think there is a workable, maintainable way of
> tagging the names of these forests at the moment.
>
> Russ
>
> On Thu, 2 Sept 2021 at 13:47, James Derrick <lists at jamesderrick.org> wrote:
>> Hi again Russ,
>>
>> On 30/08/2021 19:59, Russ Garrett wrote:
>>   > First off I would like to emphasise that I am not suggesting the
>>   > removal of any detail here.
>>   >
>>   > I am suggesting that small gaps in the forest should not be
>>   > represented by gaps in the forest polygons, but should be replaced
>>   > with man_made=cutline (and/or a highway tag), which would reduce the
>>   > number of individual landuse polygons. Larger gaps (such as the old
>>   > farmsteads, etc) should certainly be preserved, potentially as holes
>>   > in a multipolygon.
>>
>> It may be me, but these two statements seem to be incompatible.
>>
>> In several areas I have taken the time to (start to) micro-map
>> individual stands of trees with a single area. As cutlines/ firebreaks/
>> haul roads are seldom linear features (river ravines, farmsteads,
>> bothys, stone walls, shedding rings, gullys, etc), this is additional
>> information with real features useful for navigation - remember not all
>> maps are consumed on a GPSr.
>>
>>
>> Rejoining these areas into one larger area and adding linear ways to
>> represent (a few of) the gaps in trees in my mind absolutely is removing
>> detail.
>>
>> I'd all it **macro-mapping**, at the risk of creating a hashtag.
>>
>>
>> In areas where the mappping complexity is low, an outer area
>> landuse=forest plus ways man_made=cutline makes a lot of sense - it
>> gives a good balance of effort / useful detail.
>>
>> This isn't the case in Kielder, however. A lot of detail was imported in
>> the past from other sources with individual stands of trees, and broken
>> into small areas / import viewport clipping fixed later.
>>
>> As a simple example of imported data showing pre-existing areas:
>>          G3YAC imported from OS_Opendata_Natural_Line
>>          https://www.openstreetmap.org/way/131625930/history
>>
>> Would you join these relatively rectilinear areas and add cutlines?
>>          https://www.openstreetmap.org/way/131625842/history
>>          https://www.openstreetmap.org/way/131625810/history
>>          https://www.openstreetmap.org/way/131625930/history
>>
>> I was about to reference a more complex case but...
>>
>>
>>   > I'm not suggesting that the entire area should be tagged as "Kielder
>>   > Forest".
>>
>> Sadly, after looking around Kielder observatory, I see you've already
>> started merging areas and removing detail:
>>          https://www.openstreetmap.org/way/383346121/history
>>          https://www.openstreetmap.org/changeset/110350625
>>
>> A single 50km2 (roughly 6km x 4km) multi-poloygon is a poor replacement
>> for the previous detail, and I ask you to stop **macro-mapping**.
>>
>>
>> James
>> --
>> James Derrick
>>       lists at jamesderrick.org, Cramlington, England
>>       I wouldn't be a volunteer if you paid me...
>>       https://www.openstreetmap.org/user/James%20Derrick
>
>