[Talk-GB] Marking landuse and field boundaries

Tom Chance tom at acrewoods.net
Tue Jan 1 15:03:00 GMT 2013


I have been adding lots of landuse data in south east London as part of a
few projects (see recent posts tagged
http://tom.acrewoods.net/tag/openstreetmap/).

Adding farmland fields, hedges, fences and footpaths is really valuable.
The same goes for accurate landuse mapping in cities. I would ignore the
"open questions" on that wiki page, the only one I consider to be "open" is
the question of sharing nodes which comes down to personal preference.

As with all other mapping, there's lots you can glean from armchair mapping
with Bing imagery but at some stage every area needs a field survey to
verify your tracing and fill in the gaps. You can't possibly get the
relationship between field boundaries, barriers and their gaps / stiles /
gates, footpaths and the rest correct just from Bing imagery and
out-of-copyright OS maps.

You also can't cross-reference with in-copyright imagery (e.g. Google) or
maps to help you along the way.

Regards,
Tom


On 1 January 2013 14:44, Steven Horner <steven at stevenhorner.com> wrote:

> Good job there Graham. I know most of the area around there quite well.
> The Bing imagery is old, it still shows the cement works which was
> demolished in 2005 I think. Compare it to Google and you can see it is
> there no more. Although you can't use Google Satellite view to trace there
> is surely no harm in looking at it in another window to help identify if
> something is a wall or a fence then jumping back to Bing imagery to fill
> in, maybe that isn't allowed but you aren't drawing it from Google maps.
> You can see several of the bits you missed because you were unsure are
> clearly walls.
>
> Something I have been considering doing on walks is a timelapse using my
> GoPro, setting it to take pictures every few seconds which would aid in
> identifying later. The battery doesn't last long so it could only be used
> for an hour or so but I will give that a go next time. It has a wide POV so
> captures quite a lot.
>
>
> On Tue, Jan 1, 2013 at 2:09 PM, Graham Jones <grahamjones139 at gmail.com>wrote:
>
>> I guess it depends on what you think is 'difficult' - to actually survey
>> them means a lot of walking, so I tend to only add the ones that I can
>> remember when I get home, and get the routes from Bing.
>>
>> I have just had another look and for dry stone walls, it is quite easy to
>> distinguish some in Bing images, which lends itself to armchair mapping,
>> but it depends on the direction of the sun - I feel I need the shadow to be
>> confident that it is a wall I am looking at and not a track.  But a
>> reasonable guess that there is a feature there is probably more use than a
>> sheet full of nothingness...so I have just spent 20 mins with bing imagery
>> adding walls to a hillside that I know has lots of walls on it, and I had
>> started adding quite a few from my last visit (
>> http://www.openstreetmap.org/?lat=54.74429&lon=-2.09388&zoom=16&layers=M).
>>   The suspicious gaps are where I can not tell/remember if there is a fence
>> to replace the apparently disappeared wall....   Wire fences of course are
>> much harder to spot....  I'll look for the errors next time I am there and
>> correct them...
>>
>> Graham.
>>
>>
>> On 1 January 2013 11:15, Dudley Ibbett <dudleyibbett at hotmail.com> wrote:
>>
>>> My main motivation for getting involved with OSM was to get a better
>>> walking map on my garmin.   To this extent I have been adding lots of
>>> barriers in the southern part of the Peak District.  So it is being done.
>>>  Whilst it is time consuming I wouldn't say it is difficult.  I do survey
>>> with a GPS and camera as much as possible, mainly on foot.  It can be
>>> difficult to determine the type of barrier from satellite imagery so having
>>> pictures to refer to makes it easier.  JOSM supports photo mapping really
>>> well.  You do need to check GPS tracks against the imagery and be prepared
>>> to adjust the imagery offset.  I wouldn't get overly concerned about the
>>> accuracy of the position of the barrier.  A fairly good job can be done
>>> with the existing tools available and people can always adjust as these
>>> improve.
>>>
>>> I must admit I don't map land use if it is farmland.  To me if it isn't
>>> mapped it is farmland.  It would seem a reasonable default.
>>>
>>> Please give barrier mapping a go as we are out there.
>>>
>>> Dudley
>>>
>>>
>>>
>>> Sent from my iPad
>>>
>>> On 31 Dec 2012, at 22:00, "Graham Jones" <grahamjones139 at gmail.com>
>>> wrote:
>>>
>>> I would like to see field boundaries and land uses in OSM, for the same
>>> reason as you.   I think the main reason that there are not many in there,
>>> is that they are very difficult to survey.  I have just added them from
>>> memory when I have been able to remember enough - it is more realistic to
>>> add them now that we have high resolution Bing imagery for countryside
>>> areas, but it is a lot of work, even from an armchair.
>>>
>>> Graham.
>>>
>>> On 31 December 2012 21:17, Steven Horner <steven at stevenhorner.com>wrote:
>>>
>>>> Personally I would love to see fields (landuse) and the walls/fences
>>>> that make this up marked on OSM but as per the Wiki this is a complicated
>>>> area:
>>>> http://wiki.openstreetmap.org/wiki/Land_use_and_areas_of_natural_land
>>>>
>>>> I mapped a small area with landuse and some fences months ago but
>>>> refrained from doing anymore because not many others appear to be doing it.
>>>> You can see what I did here:
>>>> http://www.openstreetmap.org/?lat=54.72508907318115&lon=-1.7569917440414429&zoom=17
>>>>
>>>> Some of this I need to fix, it was my early days of OSM editing.
>>>>
>>>> I would love to use OSM one day as a replacement for Explorer (25K)
>>>> maps but until things like walls/fences are shown it would be hard to do.
>>>> My idea was to use the OSM to produce some walking guides in printed or
>>>> static form but they would need this data added for those areas.
>>>>
>>>> I know everyones view is different but do others on here use the
>>>> landuse and barrier=fence tags in the same way or does it make it look too
>>>> complicated.
>>>>
>>>> Steven
>>>>
>>>> _______________________________________________
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>>>> Talk-GB at openstreetmap.org
>>>> http://lists.openstreetmap.org/listinfo/talk-gb
>>>>
>>>>
>>>
>>>
>>> --
>>> Graham Jones
>>> Hartlepool, UK.
>>>
>>> _______________________________________________
>>> Talk-GB mailing list
>>> Talk-GB at openstreetmap.org
>>> http://lists.openstreetmap.org/listinfo/talk-gb
>>>
>>>
>>
>>
>> --
>> Graham Jones
>> Hartlepool, UK.
>>
>
>
>
> --
> www.stevenhorner.com  <http://www.stevenhorner.com>
>  @stevenhorner <http://twitter.com/stevenhorner>
>  0191 645 2265
>  stevenhorner
>
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-- 
http://tom.acrewoods.net   http://twitter.com/tom_chance
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