Library Map Part 2

This is the second in a series of posts about my new Library Map. You probably should read the first post if you're interested in why I made the map and why it maps the particular things that it does. I expected this to be a two part series but it looks like I might make a third post about automation. The first post was about why I made the map. This one is about how.

The tech stack

The map is built with a stack of (roughly in order):

• original Shape (SHP) and GeoJSON files
• QGIS
• geojson
• a bunch of csv files
• a tiny python script
• topojson
• some HTML, CSS and JavaScript
• leafletjs and leaflet plugins
• Map Box tile service

Boundary files

Since I primarily wanted to map things about library services rather than individual library buildings, the first thing I looked for was geodata boundary files. In Australia public libraries are usually run by local government, so the best place to start was with local government boundaries.

This is reasonably straightforward to get - either directly from data.gov.au or one of the state equivalents, or more typically by starting there and eventually getting to the website of the state department that deals with geodata. Usually the relevant file is provided as Shapefile, which is not exactly what we need, but is a vector format, which is a good start. I gradually added each state and data about it before moving on to the next one, but the process would basically have been the same even if I'd had all of the relevant files at the same time. There are two slight oddities at this point that may (or may not 😂) be of interest.

Australian geography interlude

The first is that more or less alone of all jurisdictions, Queensland provides local government (LGA) boundaries for coastal municipalities with large blocks covering the coastal waters and any islands. Other states draw boundaries around outlying islands and include the island — as an island — with the LGA that it is part of (if it's not "unincorporated", which is often the case in Victoria for example). As a result, the national map looks a bit odd when you get to Queensland, because the overlay bulges out slightly away from the coast. I'm not sure whether this is something to do with the LGA jurisdictions in Queensland, perhaps due to the Great Barrier Reef, or whether their cartography team just couldn't be bothered drawing lines around every little island.

Secondly, when I got to Western Australia I discovered two things:

1. The Cocos (Keeling) Islands are an Overseas Territory of Australia; and
2. Cocos and Christmas Islands have some kind of jurisdictional relationship with Western Australia, and are included in the Western Australia LGA files.

I hadn't really considered including overseas territories, but since they were right there in the file, I figured I may as well. Later this led to a question about why Norfolk Island was missing, so I hunted around and found a Shapefile for overseas territories, which also included Cocos and Christmas Islands.

Shapefiles are a pretty standard format, but I wanted to use leafletjs, and for that we need the data to be in JSON format. I also needed to both stitch together all the different state LGA files, and merge boundaries where local councils have formed regional library services. This seems to be more common in Victoria (which has Regional Library Corporations) than other states, but it was required in Victoria, New South Wales, and Western Australia. Lastly, it turns out there are significant parts of Australia that are not actually covered by any local government at all. Some of these areas are the confusingly named national parks that are actually governed directly by States. Others are simply 'unincorporated' — the two largest areas being the Unincorporated Far West Region of New South Wales (slightly larger than Hungary), and the Pastoral Unincorporated Area that consists of almost 60% of the landmass of South Australia (slightly smaller than France).

I had no idea these two enormous areas of Australia had this special status. There's also a pretty large section of the south of the Northern Territory that contains no libraries at all, and hence has no library service. If you're wondering why there is a large section of inland Australia with no overlays on the Library Map, now you know.

QGIS and GeoJSON

So, anyway, I had to munge all these files — mostly Shape but also GeoJSON — and turn them into a single GeoJSON file. I've subseque