Sunday, March 10, 2019

March 2019 Update of the East Kingdom Online Map

Boy, this has been a long time coming! With so many changes in branch statuses and postal code swaps, there really hasn't been a good time to update the East Kingdom online map. I'm aware of a pending change in Maine, but the EK Seneschal hasn't indicated any major changes in the near future. Hopefully this version will be current for more than a couple of months! The other challenge has been to figure out a workflow for updating the map data. There are two sides of the data management. Most of the SCA tracks kingdom and branch boarders by postal code areas. In the East Kingdom, we have something like 8,000 postal codes. They are classified by region, primary branches (Provinces, Baronies, and Shires), and subsidiary branches (Cantons, Ridings, and a Stronghold). Some groups go inactive or close all together, while new groups pop up from time to time. Sometimes branches grow into Crown Lands (unclaimed postal codes within the Kingdom) or neighboring branches give up or swap postal codes. It's pretty easy to just update an Excel file. The other, more challenging part of data management is updating the map data. Theoretically, each postal code in the Excel file should match a record (row) in a table that corresponds to a polygon representing a postal code area in a map file. After linking tables and filling in any blanks, the postal code polygons get dissolved by branch. (It's just too much data to serve up over the internet without seriously impacting performance.) But rather than rebuild all of the geometry of the polygons, I updated my previous work; which meant splitting, clipping, and merging existing, dissolved polygons to match the changes in the "parent" (undissolved) postal code map file. All-in-all, it took a good 16 hours to update, upload, and configure the online map. Again, hopefully this updated version will be current for a while before I have to do it again! I've created a separate page for the updated web map, listed in the column to the right. Here is a link though: