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I really need some advice on creating historical street maps using GIS software (I have access to QGIS and Diva).

Basically, I want to upload a number of historic OS sheets, which I have downloaded from Digimaps in tiff format.

I then want to create dot density (or similar) maps focusing on specific districts, which will illustrate instances of prostitution. Many of the streets I want to map do not exist any more, hence the need for historic OS maps.

I've been fiddling around with the two software packages but I am a complete novice and cannot find out how to do what I need to do.

Could anyone help?

Many thanks in advance!

(Note that this question is not a duplicate as I am looking to stitch together historic OS maps - see my comments in the discussion below).

  • Are you wanting to overlay the historic streets over a current one and are struggling with that? Or are you struggling with creating dot density? Please try to clarify your question! :) – GISKid Aug 14 '14 at 15:08
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    There are two questions here: (1) georeferencing historic maps, (2) creating points. #2 is (much?) easier than #1, but it sounds like #1 must complete before #2 can start :) I think that the Question prioritizes the georeferencing -- please clarify if I'm wrong about that. – Erica Aug 14 '14 at 15:14
  • I suggest splitting the questions. But also am aware of existing answers for both general questions separately. – Brad Nesom Aug 14 '14 at 15:37
  • Sorry, I suppose I have two questions: 1. I need to upload historic OS sheets in tiff format, and 'stitch' them together, as some districts are spread over a number of sheets. 2. Having put together the OS sheets, I then need to map instances of prostitution on certain streets - many of which no longer exist, hence the need for historic OS maps - and in certain districts. – MikeFallopian Aug 15 '14 at 11:33
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Before you can merge the maps together, each one will need to be georeferenced. Here is a QGIS tutorial for georeferencing.

Once that is complete, you want to merge the images into one bigger image. That process is called mosaic. Here is a QGIS tutorial for mosaicking.

Alternatively, you can stitch images together in GIMP or Photoshop into one much larger image before performing georeferencing. Depending on the area you're covering, this might make an annoyingly large (i.e., slow to work with) image, but that can be balanced against the annoyingly slow process of georeferencing lots of maps independently. (I would suggest georeferencing one or two maps on their own first, just to practice, and then work with the larger area.)

Once you've got that put together as a "basemap," you will be able to put the prostitution points on. If you need a tutorial for that, this one looks reasonable.

Some additional documentation/tutorial sites that may help you along your way:

  • Brilliant - thank you very much for pointing me towards these tutorials. Do I have to georeference one sheet at a time? Or would it be possible to stitch the sheets together in, say, Photoshop or GIMP, then georeference that sheet? Will I have trouble plotting the prostitution points given that a number of streets in my database no longer exist? – MikeFallopian Aug 15 '14 at 18:01
  • You can georeference any size of image, so you certainly mosaic with GIMP first (I updated the answer). I assume that you are going to be looking at the old maps to choose where to place the points -- e.g. there was an instance at Treacle Street, you have to manually look around for Treacle Street on the old maps. The difficulty of finding the right location will really depend on the quality of location information that you have. – Erica Aug 15 '14 at 21:57
  • Thanks Erica. I followed the georeferencing instructions, but it has inverted the map so everything is back-to-front and has rotated the map 90 degrees. Any ideas how this has happened? Also, do you know how to load the country boundaries shape file? Thanks for your help with this. – MikeFallopian Aug 16 '14 at 12:11
  • My guess is that the georeferencing points are out of order in some way (my main experience with georeferencing is in ArcMap, not QGIS, so I can't more specifically troubleshoot -- a new Question, maybe with a screenshot, would get you better answers). Adding the county shapefiles (assuming you've got them downloaded), look through the QGIS Training Manual or A Gentle Introduction to GIS maybe? – Erica Aug 16 '14 at 22:28

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