[Tagging] landuse=farmland and highway=track

[johnw]

> On Jan 10, 2016, at 5:21 PM, Gerd Petermann <GPetermann_muenchen at hotmail.com> wrote:
> 
> Whenever I am mapping landuse=farmland areas I wonder whether I should 
> 1) draw one rather large polygon stretching across all highway=track ways 
> and small buildings which are likely used by the farmer and waterway=ditch ways or
> 2) draw small polygons so that none of these objects is "covered".


Well, depending on how much time you want to devote to it, you can go down this rabbit hole pretty deep. 

When I first started mapping - I was trying to map my residential area, which was mostly small contoured rice fields. I ended up drawing a field only where the field itself was, ignoring the dirt berm in the center, which shows the fields, and looks good when rendering. But takes forever and needs good imagery (which is why my tracings are crap). http://www.openstreetmap.org/edit#map=16/36.4313/139.2578 <http://www.openstreetmap.org/edit#map=16/36.4313/139.2578>  

After I started armchair mapping other places (and visiting them to check to tougher spots), I still drew individual polygons for the fields when I could, with the dirt berms as borders, so they shared nodes. Fields not used for rice, I usually use shared nodes for the fields when I can. There are so many abandoned fields (now totally scrub, possibly filled with dead kei trucks) or other areas, like slopes and terrace walls that I try not to map over either. 

If that isn’t an option, then try to stay “inside” the farmer’s land. The tracks and other things around a field are probably part of the farmland, but the large drainage canals (with the mechanical water gates), almost any paved narrow public “kei truck service road”  that cuts through/around the farming areas by branching off the unclassified/residential roads leading to farming tracks, and any High Voltage towers are not part of the farm. http://www.openstreetmap.org/edit#map=17/36.35849/139.04623 <http://www.openstreetmap.org/edit#map=17/36.35849/139.04623> 

Q: is Power Tower Landuse commercial or industrial? or is there some kind of power landuse? I seemed to have flip-flopped on that as I have been tagging.



Greenhouse has the landuse=greenhouse_horticulture, http://wiki.openstreetmap.org/wiki/Tag:landuse%3Dgreenhouse_horticulture <http://wiki.openstreetmap.org/wiki/Tag:landuse=greenhouse_horticulture>

so if you have a plot of land dedicated to those plastic tube greenhouses (like many together, accessed with tracks), considering mapping all of it as that. There is also a building tag for greenhouse, as those plastic houses stay in the same spot for a decade(or 2 or 3), but mapping them is super tedious, and they render as buildings, not as some sort of half/shaded plastic thing, so the rendering on them isn’t so great. Maybe those are for the more permanent looking square ones made out of glass/thick plastic. 

~~

I was cleaning up/aligning the area around Narita, and there is a ton of very very quickly drawn/imported 1km wide farm polygons that are garbage. even if you map just between the main roads only, each should be 20-100 different polygons - they cross trunk roads and other craziness. breaking them up is more work than the tracing I did for the expressway there. http://www.openstreetmap.org/way/161736709#map=13/35.8673/140.4017 <http://www.openstreetmap.org/way/161736709#map=13/35.8673/140.4017>  here is a big one I have to split up into 50 or so fields, after I ran the tollway through. 

Anything you can do to keep the farm polygon out of the residential and above roads, which is what it sounds like you are doing, should be great. Any further detail is gravy. 

Javbw
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