Open* Software Stuff Uncategorized

Graticules in QGIS

A question came up recently on the Spatial Community slack about getting graticules for a map in a QGIS layout. This is a quick overview of making these visible. If there are unclear or otherwise problematic sections to the below, please let me know.

Showing where the 'grid' option is.
Graticules can be added by adding a grid to a given map.

This newly-created grid needs to be modified to be visible and useful, which are somewhat elaborated below.

Grid Options

Grid appearance options.
  • Grid Type: Whether you want an actual grid or just points where gridlines intersect. It is also possible to just have the numbers.
  • CRS: This defaults to whatever your project uses. A nice feature of more recent versions of QGIS is that the CRS of the grid can be different to the project’s CRS. In theory, more than one grid, with different CRSs can be added, although this may get messy. (This is done on South African geological maps, by the way: the main grid is normal lat-lon, with a secondary grid in the SACRS.)
  • Intervals Units: One of the most important options. Usually these intervals should use map units, so that you can get a gridline every degree or every 1500m or whatever suits your use-case. These can also be off-set.
  • Line Style: This accepts all of the options that a normal line can take: thickness, dashing, colour, transparency, markers, &c.
  • Blend mode: These are all of the ones that QGIS allows: overlay, addition, multiply, &c.

Frame appearance options.
  • These frame options do not create a line, necessarily (do that by adding a frame to the map option as one would with any object in the layout manager).
  • Frame Style: These should just be explored to match what you want. Zebra will put a line that changes from black to white at each interval, the various Ticks options are self-explanatory.
  • The rest of the options control which sides these elements are shown as well as colours and thicknesses and so on.

Coordinate label options.
  • These coordinates go all the way back to the CRS originally chosen. If you actually want numbers visible, then you need to enable this. Note that the various options for degree, minute, second display will only display sensible values if the CRS is one that uses those.
  • Each side of the map can be made visible or not.
  • Font: all of the usual font options are available and can be changed here.
  • Coordinate Precision: if working with metres can probably be left at 0, while for other CRSs it may make more sense to keep them in.