Friday 5 February 2016

Drains and meadows

I mapper jumped into mapping the rural areas of East Yorkshire more than a year ago but, sadly, seems to have stopped. This mapper has added farmland and woods in much more detail than anything before and has drawn the outlines of lots of buildings in villages too. There are a couple of things that I've decided to change in any areas that I take a look at now. That is meadows and drains.

Meadows are a special thing in Britain, with most having disappeared. They are not just areas of grassland but a very specific kind of management, involving no fertiliser, a careful cutting of the grass for hay more than once a year and some animal grazing, but not all year round. The timing of the hay cuts allows wild flowers to flourish as they have time to set seed before they are cut down. This makes a beautiful landscape that has all but vanished from the English countryside. The mapper has made the mistake that almost any green field in the aerial imagery is a meadow, so I'm checking as best I can on the ground and changing it to farmland unless it really is a meadow. The farmland is drawn with each field outlined which means I can try to add hedges when I see them. This too improves the quality of the rural mapping.

The other problem is that every field-side ditch has been mapped as a drain. This is further worsened by another mapper doing the same thing in Holderness, the flat land to the east of Hull. There are some waterways I would call a drain there, but most are ditches in my view. A ride out doesn't cover much ground to correct this and imagery is ambiguous at best. So there's lots to check and much will change.

The East Riding countryside is a great place to spend time; having an excuse to carefully explore and examine more of it in detail is no bad thing, so I'm not complaining.

Tuesday 2 February 2016


People meet up in a few areas across Britain drawn together to share views and ideas about OSM. One of these is known as Mappa Mercia, meeting in the old Kingdom of Mercia, roughly the Midlands. They started a quarterly series of projects which encourages people to focus on improving specific areas, such as nature reserves. This quarter it is schools.

People across Britain have taken to the suggestion of checking schools and improving the quality of recording schools. This is a simple idea that will greatly improve the quality of data in OSM, something that the quarterly projects have always aimed at. It's a great idea and something I support.

There is a list of UK schools available as open data which Robert has used to show a map of how well the schools in the list are represented in OSM. It uses postcode areas as that is how the open data is structured. This is a very good indicator of areas that still need work.

This is all useful, but then I think the project took a wrong turn. People were encouraged to add a hashtag to changeset comments. This has then been used to produce a list of people who have contributed the most changes to the project. I don't like this. OSM is not a competition and turning it into one encourages edits just to climb the list (I'm not accusing anyone of that, just that the pressure is created). We have seen that with the list of anomalies published between OS Locator road names and OSM road names. To push an area up the list people just use the OS Locator names without checking. I know that OS Locator contains errors and there is a mechanism to record these, but many areas have very few recorded errors, so erroneous OS data is now in OSM.

I like the idea of focussing on improving specific things in OSM. It should encourage surveying. I would prefer it is not be seen as a competition.