At some stage in the second half of 2020 the Central Statistics Office released the population for each townland in Ireland for both the 2011 and 2016 censuses. They had a category for both data that has been suppressed ‘-1′ and the townlands that were unpopulated ‘0′. I think it’s a safe assumption that if you read (or have stumbled upon my blog) that you too might be interested in maps of unpopulated places. Below is the static map I posted on Twitter and Reddit and (by popular demand – read as two random people on Reddit) I’ve also included a slippy map that you can examine at your leisure.
I was reading Alasdair Rae’s street types blog post yesterday and I thought about doing something similar for Ireland. I didn’t have much time today so I said I’d put something quick together for Cork City. Alasdair was lucky that he could use the amazing open data from the UK’s Ordnance Survey. For Ireland, we don’t have anything similar from our national mapping agency but fear not because it’s OpenStreetMap to the rescue. In my humble opinion individuals often spend far too much time trying to get a usable output from overpass-turbo when there’s an easier way. What I did was download the .osm.pbf file for Ireland from Geofabrik. Windows Subsystem for Linux has been a lifesaver since it came along, most of the heavy lifting I can now do through it. The steps I followed are as follows:
1. Download the .osm.pbf file using wget.
2. Install the osmium-tool
3.Filter out just the ‘highways’ from the dataset and save it to a new .osm.pbf file
4. Convert the .osm.pbf file to a new shapefile ( I don’t normally use shapefile but converting to a geopackage was causing some issues in this instance).
I could have made this more efficient again by combining some of these actions (such as save as a new shapefile and reprojecting), I did it this way to make the process easier to explain.
Next I brought the dataset into QGIS and extracted an area just for Cork City. The main issue I then has was how to ascertain what road types occur most frequently. I exported the Cork City extract as a CSV and imported it into Excel. I then used a generic formula from the folks at exceljet to extract the last work from the ‘name’ column. I then counted the frequency of the extracted work in a pivot table to get an idea of the types I’d like to use.
Frequency of Road Types
The last thing I did was to create a new field using an expression to find the various road types in the ‘name’ column from the OSM data. The expression I used is the below:
WHEN "name" LIKE '%Road%' then 1
WHEN "name" LIKE '%Park%' then 2
WHEN "name" LIKE '%Street%' then 3
WHEN "name" LIKE '%Avenue%' then 4
WHEN "name" LIKE '%Court%' then 5
WHEN "name" LIKE '%Drive%' then 6
WHEN "name" LIKE '%Hill%' then 7
WHEN "name" LIKE '%Lawn%' then 8
WHEN "name" LIKE '%Estate%' then 9
WHEN "name" LIKE '%Place%' then 10
WHEN "name" LIKE '%Lane%' then 11
I then symbolised the data and exported it. The final product is below. Obviously this was a pretty quick and dirty way to do it and if I create an atlas for every major town in Ireland I will use PostGIS which will allow me to count the frequencies and create the new field with ease.
I was hiking at the weekend and it got me thinking about the unpopulated areas of Ireland. I’ve seen maps made for the 2011 census showing the square kilometres that have no usual resident population but I hadn’t seen one for the 2016 census so I put together the below. I purposefully omitted Northern Ireland because the data is nine years old. If anybody would like the replicate the below just leave a comment and I can do a YouTube tutorial or post on here on how I put it together.
A topic that I think about frequently is the physical changes Ireland has gone through over the last 10 or 20 years. I’ve covered it before in this blog but I’m going to look at it again today. I think you could ask anybody around the country where the development in their town has been during the Celtic Tiger and this current boom period (well, up until the Covid-19 outbreak anyway) and they would easily be able to tell tell you.
It’s true that we have national indicators from the Central Statistics Office identifying where the most planning permissions have been granted as well as data from the Department of Housing, Planning and Local Government on new ESB connections to show where new homes have been constructed. I was looking for something that would give an idea of the physical development that has occurred in the last 20 years.
Enter the CORINE Land Cover Inventory. It started in 1985 as a way for the European Environment Agency (based in Copenhagen) to monitor the main land uses in the Union. As a little factoid, it stands for Coordination of Information on the Environment. It contains 44 land use classes and the cell size is 100 metres. It already contains layers that show the change between different years but it didn’t contain any change layer from 2000 to 2018. I wasn’t interested in the 44 classes, in fact I was only interested in the categories shown below. I decided to omit construction sites, dump sites and a few other inconsequential categories. These are the main categories that will show development in Ireland between those years.
111 – Continuous urban fabric 112 – Discontinuous urban fabric 121 – Industrial or commercial units 122 – Road and rail networks and associated land 123 – Port areas 124 – Airports
I used the the wonderful r.reclass GRASS tool in QGIS in order to reclassify the rasters for both the year 2000 and the year 2018 to combine these categories. I then used raster algebra in order to subtract the year 2000 from the year 2018 raster in order to show the actual change. Below is a GIF showing the process for an area of North Kerry and Cork.
QGIS Process Example
I create the below map in A1 so you can zoom in to get a good sense of what 18 years of development looks like in a particular county.
Finally, after a few unsuccessful attempts at converting the final raster to vector I used the gdal_polygonize tool which did it seamlessly without any loss of the smaller cells. Below is the final layer as a web map that you can make full screen.
There are a few interesting area that were developed in those 18 years such as Aughinish Alumina in Co. Limerick:
There are also a few windfarms such as this one in Tyrone:
After completing the above I thought I’d put together a map showing the peat cover in Ireland. Besides from the CORINE land cover dataset I used a DEM from the European Space Agency to create the hillshade and the administrative data comes from Ordnance Survey Ireland and OpenDataNI. The dataset doesn’t differentiate between raised and blanket bogs but for my purposes that’s okay.
Below is the finished map. I tried something new and used abbreviated county name labels à la various maps for the USA where the state names are abbreviated. I think it works well.
I was thinking since I posted this that there’s a bit of work involved to figure out the order of peat per county so I created a graph. For any GIS folks out there, I quickly unioned the county layer and the peat layer and then calculated the area in square kilometres for the peat and exported this as a CSV. I then used Matplotlib to create the below graph. If you’d like to know more about simple workflows like these just reach out to me on Twitter (@pearoid).
I was reading this Guardian article the other day where they produced maps showing the number of Airbnb listings per 100 dwellings. I thought it was really interesting and I hadn’t seen Airbnb data mapped like that before. I had a few hours to spare yesterday so I set about replicating their method for Ireland. I used the 2016 census electoral divisions (to get the household numbers) and data for Ireland from Inside Airbnb. I think at best this data is questionable because from the reading I’ve undertaken it seems to still list properties that were briefly on Airbnb a number of years ago and have long since been removed however this is the only data available so I went with it.
Below is the map, it was made with a combination of Bash, GDAL, QGIS, LibreOffice Calc and Illustrator.
In Ireland, the townland is the smallest unit of land division. They pre-date the Anglo-Norman conquest (source). What I find amazing about them is how prevalent their use is to this day. Where I grew up in Kerry, they are still used, day-in, day-out to give everything from directions to advertise property and house sales. I find this fascinating; what also amazes me is the number of discussions that occur among friends and in the community regarding townlands and their exact boundaries. Until the OSI released the below dataset, any disputes on the boundaries would have to be resolved using someone’s copy of maps from the 19th Century. It is great to be able to solve these using accurate data.
There has been an OSM project ongoing with a few years to map all the townlands of Ireland. The Ordnance Survey of Ireland released the townland boundaries as open data under a creative commons licence. There are no townlands for the cities of Dublin and Cork but they cover the rest of the country. There are 50,380 townlands in this dataset.
Townlands of Ireland
Because the ArcGIS Online viewer isn’t fantastic, I uploaded the townlands to Carto to view online. I have only uploaded the 50m generalised dataset as the ungeneralised dataset is ~240MB. Below is a Carto web map of the townlands of Ireland. I hope to do some work in the future on these townlands, such as general statistics and such.