Brendan Harmon

Cartography in QGIS

Rivers of Europe

Contents


Download Data

Find raster and vector data of the world in the Natural Earth collection. Download and extract:

The coordinate reference system for these datasets is the World Geodetic System 1984 (WGS84). Move these datasets to a new directory on your computer called natural_earth.


Import and Package Data

Start QGIS with an empty project. In QGIS’ Browser browse to your natural_earth directory. Consider adding it to your favorites. Right click on the natural_earth directory to create a new GeoPackage called natural-earth-from-space.gpkg. Then save the current project as natural-earth-from-space.gqz in the natural_earth directory.

In QGIS’ Browser drag and drop the following into natural-earth-from-space.gpkg:

  • ne_50m_graticules_15
  • ne_10m_admin_0_countries
  • ne_10m_lakes
  • ne_10m_rivers_lake_centerlines_scale_rank
  • ne_10m_rivers_europe
  • NE1_50M_SR_W.tif
  • NE1_LR_LC_SR_W_DR.tif

This will import these data into the GeoPackage dataset for more efficient storage and easier portability. In QGIS’ browser double click on the data in the GeoPackage to add them to the map.

Start by turning off all layers except for the countries and graticules. Style the countries with a simple fill with fill color set to grey, stroke color set to white, and a stroke width of 0.2. Style the graticules with a simple line in black with a stroke weight of 0.3.


Azimuth Orthographic Projection

Locator maps simply show where a project located. They can be inset in more detailed maps to establish a wider context. Use an azimuth orthographic projection to create a globe for an inset map. First set a predefined azimuth orthographic projection. In the project menu, select properties. In the properties dialog, select the CRS tab and search for the The_World_From_Space projection. Copy the PROJ definition for this projection. You will use it to make a custom projection in the next step.

To set a custom azimuth orthographic projection centered on your study area, go to the settings menu and select custom projection. Use the plus button to create a new CRS, name it Custom_World_From_Space, set the format to proj string, paste the PROJ definition for the The_World_From_Space, and then edit it. Adjust lat_0 and lon_0, the latitude and longitude of natural origin to focus on your study area.

+proj=ortho +lat_0=42.5333333333 +lon_0=-0.5 +x_0=0 +y_0=0 +ellps=sphere +units=m +no_defs

Back in project properties in the CRS tab, search for your new Custom_World_From_Space projection and set it as the CRS. Then in the custom CRS dialog, try adjusting the Latitude and Longitude of natural origin value to rotate the globe until it centers on your study area. For this tutorial, focus on Europe.

Azimuth Orthographic Projection
Azimuth Orthographic Projection

Try turning off the ne_10m_admin_0_countries vector layer and turning on the NE1_50M_SR_W raster layer.

Azimuth Orthographic Projection of Natural Earth
Azimuth Orthographic Projection

Extract a Continent

Extract a vector map of Europe from ne_10m_admin_0_countries to show your study area on the locator map. In the Plugins menu select manage and install plugins. In the Plugins window check the Processing plugin. This is a core plugin so it does not need to be installed, but it does need to be activated. The spatial data processing framework for QGIS has algorithms for geospatial computation. A panel with the Processing Toolbox should appear on the right side of your main QGIS window. In the Processing Toolbox browse in Vector Selection for Extract by attribute. Run Extract by attribute. Set the input layer to ne_50m_admin_0_countries, set the selection attribute to CONTINENT, set the value to Europe, and set the matching features to ogr:dbname='natural_earth.gpkg' table="europe" (geom). Nota bene: use the full file path for natural_earth.gpkg.


Themes

You can save different arrangements and styling of layers as themes. Themes are very useful for setting up print layouts with multiple maps with different styles. To style the locator map differently than the main map, create a theme for each.

Set up a theme for the locator map. For example arrange the following layers in order from top to bottom:

  • ne_50m_graticules_15
  • europe
  • NE1_50M_SR_W.tif

Style the graticules as simple line in white. Optionally, set graticules’ opacity to 50%. Style europe with a simple fill with a blue fill and a dark blue stroke. Create a new map theme by selecting the manage map themes button in the layers manager. Choose add theme to create a new theme called globe.

Set up a theme for a map of rivers in Europe. For example arrange the following layers in order from top to bottom:

  • ne_10m_lakes
  • ne_10m_rivers_europe
  • ne_10m_rivers_lake_centerlines_scale_rank
  • NE1_LR_LC_SR_W_DR

Style lakes with a blue sampled from the ocean in the Natural Earth raster with a transparent stroke. Style the supplemental European rivers with a blue stroke with a weight of 0.075. Style the rivers with blue strokes weighted based on stream order. Set a data defined override for the stroke width. In the data defined assistant set the source to strokeweig, refresh the input values, and set the output value size from 0.1 to 1.25. Consider adding labels for the larger rivers. Create a new map theme by selecting the manage map themes button in the layers manager. Choose add theme to create a new theme called map.


In the project menu select new print layout and create a new layout called rivers-of-europe. The print layout window will open with a blank canvas. In print layout create a map of European rivers in a projection such as Lambert Conformal Conic with an inset locator map in an azimuth orthographic projection.

Use the add map button in the toolbar on the left side of the print layout to draw a new map canvas. First add a map spanning the whole canvas. In the items panel, select and rename this as map. In the item properties panel under the main properties section set the CRS to a projection such as Europe_Lambert_Conformal_Conic. Set a fixed scale such as 15000000. Then in the layers section check follow map theme and set the theme to map.

Add a scale bar your map. Select it in the item panel, then in the item properties panel set the style to numeric.

To create the inset locator map add another map to the canvas. Click the add map button and drag and drop a small square window in the upper left corner of the canvas. In the items panel, select and rename this as inset. In the item properties panel under the main properties section set the CRS to Custom_World_From_Space. Set a fixed scale such as 200000000. Then in the layers section check follow map theme and set the theme to globe. Uncheck background to hide the white background behind your globe.

Finally use the export as image button to export your map as a .jpg .

Rivers of Europe
Rivers of Europe
Natural Earth Map of Europe with Rivers
Natural Earth Map of Europe with Rivers