I was rereading this article (warning: paywall) in The Economist from 2023 that states:
In 1960 the median distance between African cities was 84.3km; in 1990 it was 55.7km. By 2015 this had fallen to 27.3km.
This got me ruminating on what it is for Ireland? I haven’t done it historically, just for the latest census data available (2022).
I used the ‘Built Up Areas’ (BUAs), and the ‘Distance Matrix’ tool with the following settings:
- Both the input and output layer set to the centroid of the BUAs;
- The ‘Output Matrix Type’ set to ‘Linear (N*k x 3) distance matrix’; and
- To use only the nearest 1 target point.
The median distance between BUAs in Ireland is 5.289km.
Castletownbere has the greatest distance to its nearest neighbour, with Sneem being 20.564km away.
The closest nearest neighbour pair is Killaloe, Co. Clare and Ballina, Co. Tipperary. They are separated by approximately 120m (across the Shannon), as the distances were calculated to the centroid and I manually measured the width of the Shannon.