Creating OpenStreetMap History Visualisations

I created a couple of OSM visualisations for my talk at the OSGeo Ireland conference.

See: History of OpenStreetMap in Ireland

These are pretty easy to make, but take a fair bit of time. I did mine for Ireland, but should work with any part of the world.

Required software:

This is the trickiest part, installing osmium-tools: here.

Data:

An OSM full history export. The best source for these is GEOFABRIK.

For Ireland:

http://download.geofabrik.de/europe/ireland-and-northern-ireland.html

Due to GDPR, you will have to log in with an OSM id to download the full history extracts. User ID’s are personal data.

Process:

The workflow is pretty simple. Osmium-tools provides pretty easy API access to the history files, where you can provide a data, and it will extract what OSM was like at that date. We simply need to loop through the desired dates we want to extract, and pipe the results into a workflow that loads the data into PostgreSQL. The final step is simply rendering in QGIS using the time manager plugin.

Python Script:

Github GIST:

https://gist.github.com/HeikkiVesanto/f01ea54cca499a6a144d18cf8909c940

The tables in the database will be:

  • lines
  • multilinestrings
  • multipolygons
  • other_relations
  • points

Each feature will be tagged with the date it is associated with.

Visualisation:

To visualise the data in QGIS we use simply use the excellent time manager plugin, filtering on the load_date field and with a monthly interval.

Result:

History of OpenStreetMap in Ireland

Last week I was invited to give a workshop at the Second Irish OSGeo Conference in Portlaoise. The event was a great success with a attendees from across the OSGeo space, from academics to startups.

I also volunteered to give a talk on OpenStreetMap (OSM) in Ireland. Since we are currently in the process of setting up an official chapter of OSM in Ireland. Check out OpenStreetmaMap.ie if you want to help.

Check out my full talk: here

But some of the visuals are more interesting than the talk as a whole.

To start out, the first edits in Ireland.

The first line:

Located in Banbridge, in Northern Ireland between Newry and Belfast:

First polygon:

Clearly St. Stephens Green, a great park in Dublin:

Then a look at the full history of roads in Ireland on OpenStreetMap:

A large part of the history of OpenStreetMap in Ireland is the townlands project. Townlands in Ireland are small divisions of land, often used in addressing for example. Your address could be: Mr. O’Brien, Blue house, Tawny (the townland), Donegal. The postman knows where you are.

There are over 61,000 townlands in Ireland. Traced manually from 650+ out of copyright OSi maps from Trinity College. Check out Townlands.ie for more info.

The project ran from 2012 to 2017 and the progress is clear when charting the history of boundaries in OpenStreetMap in Ireland:

And since the conference was held in Portlaoise, here is how it looks over time in OSM:

For the script to generate these histories see: Creating OpenStreetMap History Visualisations

QGIS Select Within Plugin 0.4

Version 0.4 brings a couple of new features to the Select Within plugin.

Most importantly it now supports mostly within and percentage within selections.

Also introduced is Pole of Inaccessibility within selections. As implemented in the QGIS core with the Polylabel algorithm: https://github.com/mapbox/polylabel

Point within selection examples. Centroid (red), Point on Surface (green), and Pole of Inaccessibility (blue):

Examples:

Centroid within:

Point on Surface within:

Pole of Inaccessibility within (1.0 tolerance):

50% within:

75% within:

Code:
GitHub Code Base

Issues and bug tracker:
GitHub Issues

QGIS Multi Ring Buffer Plugin Version 1

After about 3 years of existing. I am releasing version 1 of the Multi Ring Buffer Plugin.

QGIS plugin repository.

With version 1 comes a few new features:

  • Ability to choose the layer to buffer after launching the plugin
  • Ability to supply buffer distances as comma separated text string
  • Ability to make non-doughnut buffers
  • Doughnut buffer:

    Non-doughnut buffer (regular):