[Imports] Building Footprints in Kariba, Zimbabwe

Michael Reichert osm-ml at michreichert.de
Wed Feb 13 13:32:14 UTC 2019


Hi Jason,

Am 13/02/2019 um 11.52 schrieb Jason Owen:
> *What are the requirements?*
> The Local Authority is aiming to release an android app in March this year
> that allows local residents to geolocate urban issues such as potholes,
> street lights not working etc. These issues are emailed to the responsible
> people through the app (the app is built on the open source FixMyStreet
> <https://www.fixmystreet.com/> platform which makes use of OSM for
> geocoding). The address system in Kariba like most of Zimbabwe is quite bad
> - one thing that does work is a "stand number" which is given upon purchase
> of a plot/property and and that many people post outside their houses. In
> my opinion this is the best option for geolocation in Kariba. Hopefully one
> day we have a good address system but for now many streets are not named
> and many houses do not have street numbers...

Does a building get a new number if it is is built on a plot with am
existing building? Or do the two neighbouring buildings (the old and the
newly built) share a stand number?

Are stand numbers only unique within a city or a borough? There is
something similar in Germany (and other European countries as well). A
lot of smaller villages do not have street names. When a building is
built, the local authorities assign the next free number. Only buildings
in the centre of these villages seem to have ordered number because they
got their numbers en bloc when addresses were introduced. These numbers
are only unique within the village. The name of the village is used as
street name in postal addresses in these cases and addr:place used
instead of addr:street.

It looks to me that addr:housenumber=<stand number> + addr:place=<name
of city/borough> is a valid tagging in your case.

> *If its to associate a particular plot code with a building or plot then
> could you just add a tag to the existing building?*
> Yes this is an option. I have downloaded the OSM data for Kariba from
> Geofabrik. Can I update the tags "type" and "name" in QGIS and then upload
> the whole shapefile of buildings with updated tags using JOSM... this would
> be more efficient than manually tagging each one.

It looks easier but it bears the risk that you mess up data by
automatically editing it. Don't underestimate the conflation of existing
OSM data with your data.

In addition, an import should not replace existing geometries in OSM by
new objects just because it is "easier". Instead, the existing
geometries should be modified to preserve their history.

> *Do you want to map the plots independently of the buildings?*
> This is another option since the plots are different from the buildings as
> John has pointed out. I see there is also a landuse layer in OSM - would I
> be replacing/updating that or creating a whole new layer?

There are no layers in OSM in usual GIS sense.

Did you get familiar with OSM in the past by doing some mapping in OSM
in the area where you live and/or which you know well, e.g. adding
points of interest or enhancing the map with local knowledge? It helps
one to understand how OSM works, how the data looks like, how good the
data is and what to do if things go wrong.

I think that people on this list can give concrete advice if you write
down your plan on a wiki page as others imports do. You will find
examples in the archives of this mailing list.
https://lists.openstreetmap.org/pipermail/imports/

Best regards

Michael


-- 
Per E-Mail kommuniziere ich bevorzugt GPG-verschlüsselt. (Mailinglisten
ausgenommen)
I prefer GPG encryption of emails. (does not apply on mailing lists)

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