4. Import Datasets

To review the difference between raster and vector data, visit the Introduction .

Raster data

If you haven’t already, download and install QGIS .
Open QGIS.
Open a New Empty Project.
In the left-hand Browser menu, find the dropdown titled XYZ tiles.
Expand the XYZ tiles dropown and double-click OpenStreetMap to add a basemap to your project. The basemap exists in the background of the project to give us a reference while we are working.
In the banner that runs across the top of the QGIS project, find the Zoom in button. Select this button.
Click and hold to drag a square around Europe. You can also scroll in and out on your mouse to Zoom in and out. To pan around the map without zooming, engage the Pan map button, which looks like a hand.
In the left-hand browser menu, right-click XYZ Tiles and select New Connection.

We are adding the map of Poland nationalities. This map has already been georeferenced. Georeferencing maps like this one allows us to overlay it onto other maps and directly compare maps and data of the same area. The map is currently hosted online as a streaming data layer. We can bring it into our project by specifying in QGIS what the layer URL is.

In the XYZ Connection wizard, title the new layer Poland Nationalities 1919.
Copy and paste the following link into where it asks for a URL: https://allmaps.xyz/maps/8d5cc5d1fec615d6/{z}/{x}/{y}.png

To learn how we georeferenced this map from our Digital Collections , you can follow this tutorial .

Accept all other defaults. Select OK.
Make sure the dropdown caret next to XYZ Tiles in the browser menu is expanded. To add the Poland Nationalities 1919 map layer to your QGIS project, double-click on Poland Nationalities 1919. You should be able to see the old map overlaid on the basemap now.

It might take a few moments to render. As you zoom in and pan around, you are querying the map data at different zoom levels. The resolution should improve as it finishes loading.

Vector data

Download the zipped data from this Google Drive link .
Uncompress the zipped data folder. If you need help unzipping folders, follow the steps on this website .
In the very top QGIS program menu, select Layer → Add Layer → Add Vector Layer.
In the Data Source Manager, Under Source, click the ellipsis next to Vector dataset(s). This will open your computer’s files. Navigate to where you downloaded and unzipped the project data. In the allenstein-region folder, select the file allenstein-region.shp.
Select Open.
Select Add and Close. The allenstein-region layer should now appear in your layer list, and on your map.
Follow the same prompts to add the Polish cities statistical data. In the Data Source Manager, Under Source, click the ellipsis next to Vector dataset(s). This will open your computer’s files. Navigate to where you downloaded and unzipped the project data. In the poland-stats folder, select the file poland-stats.shp.
Select Open.
Select Add and Close. The poland-stats layer should now appear in your layer list, and on your map. Your map document should look something like this. All three layers, the georeferenced map, the allenstein region, and the polish cities statistics.
Let’s make this data a little easier to work with. Double-click the allenstein-region layer in the Layers Panel. This will open up the Layer Properties for the allenstein-region shapefile.
Select the Symbology tab from the Layer Properties menu.
We want to change the symbology on the plebiscite region layer so that instead of QGIS symbolizing the region as a solid shape, it is just a border around the region. Select where it says Simple Fill.
In the Fill Style drop-down, change Solid to No Brush.
Let’s change the border outline, or “Stroke”, to a color and width that appears a bit more prominently against the detail of the bold colors on the historic map. Click the colorful bar which appears to the right of the Stroke Color option to open the Select Stroke Color menu.
We’re going to use a light greenish color which will pop against the map background. Paste the color code for this color into where it says HTML notation. The value to paste in is #e0f3db

To learn more about color codes, check out htmlcolorcodes.com .

Increase the Stroke Width to 1.0.
Select OK
This works better for us, because now we can see the extent of the plebiscite region, but can also “peer under” the layer to see the details of the historic map. Your map should look something like this.
Now let’s label the Allenstein region. Double-click the allenstein-region layer in the Layers Panel again, to open up the Layer Properties.
Select the Labels tab in the Layer Properties menu.
Select the drop-down that says No Labels, and change it to Single Labels.
Select the Text tab, and change the size of the label to 14.0.
Click the color bar next to Color and paste #eee as the color code into the HTML notation field.
Let’s add a drop shadow to make the label stand out better against the map background. Select the label tab called Shadow, and toggle on Draw drop shadow.
Select OK. Your map should now look like this, with the Allenstein region outlined and labeled.
The points representing the Polish cities in the poland-stats layer are also quite small and difficult to see. Let’s make them bigger. Double-click the poland-stats layer in the Layers Panel to open the Layer Properties.
Select the Symbology tab.
Select where it says Simple Marker.
In the text box next to Size, change the marker size to 6.0.
Select OK. Your map should look something like this.

Next lesson: 5. Visualize statistics →

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