I've been pondering landuse again.

Some people seemed to be confused by using the tag landuse=farm for mapping farms fields AKA farmland AKA farms! A field is part of a farm is it not? The confusion seems to come when people see the farmyard tag. So let me help you out here:

[UPDATE: This is a very old 2009 diary entry. Some of these issue have now been clarified in the documentation. In particular landuse=farm has since been documented as clearly the wrong tag to use]

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To be fair though, this does leave some unanswered questions. There are many awkward questions about mapping landuse, which haven't really been answered with any kind of guidelines as far as I'm aware.

What is the ideal end-goal for landuse mapping? Are we aiming to map out landuse everywhere? So here in temperate European climes this logically means we'll be mapping a whole lot of farms. Do we really want to use the landuse=farm tag to cover all of the farmland which makes up most of the land area of our countries? Do we want to map this as many little areas e.g. around each farmer's land, or some kind of all encompassing big area punctuated by cities which will sit as islands within the sea of farm land? What about mapping desert surrounding cities like Las Vegas? Currently there are some patches of desert tagged, where it useful to illustrate these appearing between suburban/outlying areas of housing, but eventually the cities gives way to whole Nevada desert. How to map that?

And how much detail should we go to when thinking about landuse? This is a question for the countryside (Do we want to draw areas around individual farms, or individual fields?) but also for the city (Do we want to delineate exact borders around landuse=retail? If there's a shop in the middle of a residential area, should we do a little pink retail area for that? Over the top? What about if there's five shops? )

A question for the renderers: If we go ahead and fill in landuse=farm for large areas of our countryside, how should this look on the map? There's some good (or bad) progress mapping landuse=farm around Wakefield, so here's the question. Should the whole map of England be turning bright green or brown or something different?

All these areas can create lot of troublesome data mess. The areas are fiddly to work with in editors, especially in the city where there's all sorts of other way-node clutter in the mix. When we look at the nitty-gritty data details, what is the recommendation for landuse areas? Do we draw the areas sharing nodes with roads? (way segments on top of each other. eugh! I'm not a fan of this approach myself) or draw in parallel? in which case, how close should these parallel way segments be drawn? And what about where two landuse areas meet each other with no road between. Share nodes then? Should footpaths going into parks include a connecting node with the area of the park? Or should we try to separate out all landuse data from other types of data? And how should little areas interact with building outlines? How can editors be improved to make this easier?

Lots of questions, but in my OSMing experience, it's always better to just get on a map stuff. It's better because it helps you to gain a practical understanding of mapping problems, and realise that some problems don't matter as much as you might think. It's also better to work on real problems rather than theoretical problems. For example the farm rendering question is a real question when you look at Wakefield, because somebody went ahead and mapped the farms!

So enough of this pondering. I'm going to try and do more landuse mapping, starting with some pink landuse=retail along Oxford Street (finally, after three years, that funny patch of landuse in Marylebone sticks out a bit less)