At 5:20 pm on 12/12/2022, the mapping part of the Cavan task was finished today*. Special thanks go to local mapper AdrianLangtry who did great ground work in Cavan and Ballyjamesduff as well as to mapillary constributors debigc and Elomur for providing fresh mapillary imagery focussing on Virginia which was also very useful for mapping details. Lets hope we can keep those two new-ish mappers interested…

*Sounds like a birth announcement, and rightly so.

One of the challenges mapping Co. Cavan was the imagery. The northern part had very clear, fairly recent Bing imagery. This part of Co. Cavan was finished first, because it was motivating to use clear imagery. For the southern part, Esri Clarity was the fall back with occasional use (should have been more) of Maxar. Maxar should definitely be used there for the validation process.

The “Great Cavan Schism”

Buildings

Increase of buildings during the task

The number of buildings during the duration of the #osmIRL_buildings in Co. Cavan campaign (up to 05/12/2022) increased from 6,900 to 55,300, according to ohsome.org/apps/dashboard splitting into

building typenumber on 12/12/2022
yes29,225
house27,265
terrace772
detached292
semidetached_house583
farm_auxiliary10,306
garage4,069
shed3,119
greenhouse439
industrial248
retail155
commercial138
church120
school101
hotel39
static_caravan24
hospital11
Distribution of building types (source:overpass-turbo)

According to overpass-turbo, the total number today is ~ 77,000.

Highways

The total length of mapped highways during the campaign increased from 3,871km to 5,497km (increase of 42%).

Other car related features

Due to the excellent imagery, it was possible to add highway=stop (increase from 138 to 273) as written on roads and disabled parking spaces (increase from 4 to 101). This was, of course, only possible with the new Bing imagery.

Landuse

Due to the number of lakes in Co. Cavan (allegedly 365, should definitely be possible to be counted now), many of which had been partly drained in the past, great areas of wetland were added also during this task.

landuseareaincrease on OSM since 2019
natural=wetland229.km21305%
forest124km2103%
residential16.2km267.9%
natural=wood11km274.3%
grass0.9km255%
farmland*2.2km232.1%
*mostly mapped around Cavan (town)/ Ballyjamesduff

Historic features

Because it was myself that was in it, many “new” historic features (sounds like an oxymoron) were added as well. Apart from the at least 3 newly discovered crannógs, that is.

historic featuretotal number as of Dec 2022
ringfort204
crannóg86
megalith~24
church19
holy well14
castle7
cillín1
number of some historic features after completion of Cavan task

To do for validation

As per usual, the number of building=yes can probably be reduced. It would also be useful to use Maxar imagery in the second round to add possibly missing buildings and maybe even adjust road alignments.


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