Greater Sydney railways

Does the rail corridor provide an important ecological niche for wildlife in the Greater Sydney region?


November 30, 2022



  • Clients had observed that in some parts of Sydney the rail corridor provides pockets of valuable habitat for native wildlife.
  • They were interested in finding out whether we could quantify the overall proportion of such possible habitats in the rail corridor in the Sydney Basin.


  • Identified and retrieved optimal geospatial datasets for carrying out this analysis, including government and open street map railway annotations and two models of land cover.
  • Overlapped railways with lot annotations, and carried out substantial data cleaning to remove artifacts such as tunnels, bridges, model railways etc.
  • Replicated ArcGIS approach to polygon overlaps in R (a surprisingly non-trivial task).
  • Built a dynamic website so clients could browse and share results with stakeholders, as well as view what had been filtered.


  • Project was funded by clients.
  • Other results still under embargo.

Key tools

  • R: terra, sf, exactextractr, rgdal, leaflet, tidyverse, janitor, skimr, htmlwidgets, plotly; Git + GitHub.