Mapping Leuven in 1649 with QGIS

On the 11th and 14th of May, dr. Catherine Jones introduced us to Geographical Information Systems (GIS) with the help of Kerry Schiel and Kaarel Sikk. On the first day we mostly learned how to work with QGIS uploading existing maps and exploring the Bombsight maps. We also started from scratch ‘stitching’ an old map to the open street map or google maps based on points that we could still recognise and overlap. Depending on how recent and/or accurate the historic map was, we had to choose a different transformation type. After wasting time locating buttons during the tutorial because the interface wasn’t entirely intuitive and many of the concepts were new, we got the hang of it. For the assignment, I decided to repeat the process with an historic map from Leuven where I was born and where I spent six years at the university. Since the resolution of the map I tried to use during the tutorial was too low, I found a more recent map (from 1649, rather than 1541) from the Atlas van Loon. Before uploading the historic map, I set the projection to TRS89 / Belgian Lambert 2008. Although Leuven has changed a lot the last four centuries, I could stitch the map mostly based on the locations of churches still in existence today. I have to admit that being a local really helped me locate some of these rather quickly. Once the eleven points were identified on the open street map, I used the Thin Plate Spline which stretches the historic map as if it were made of rubber because that made most sense for this rather old map.

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At the end of the first day and the beginning of the second day we learned how to insert and adapt data points such as locations of bombs that fell on a certain day of the week, or flight paths and areas affected by larger bombs in London. For my own project I decided to locate the original items of the legend and used the number of the location in the original legend as an id and the name of the item in a second field of the data table. At first I tried to find the buildings and locations (mostly churches, colleges and squares) in the order of the original legend, but after a serious struggle to find nr. 11 on the list, I decided to systematically look at areas of the maps and locate the numbers of the legend first before adding a data point. Once I finished locating most of the points, I looked at the data table once more and realised I had made at least two mistakes by identifying the same building twice on different locations. Luckily the points on the map light up if you select a row in the data table which made it easy for me to correct the errors. In the end I made a list of all the legend items I didn’t find and found a list and links to the heritage inventory that were useful in a final attempt to locate them. I managed to find two more buildings, but 11 out of 74 were not to be found (even though for some I knew for sure where they were).

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I can add labels and some more metadata to the dots, for example which type of building it is (university or religious building) and give those a different color. Another option is to outline the original city walls (the ‘binnenring’ and ‘buitenring’) or identify which areas contained housing, where the gardens were, and which plots were used as agricultural areas. In any case I really enjoyed the workshop and learned a lot, only time held me back to add extra data layers. The interface has a learning curve, yet can be very useful.