In a previous blog post I had described how to acquire real world geographic data on an island and massage it into a reasonably plausible continent.

In today's blog post, I describe how to use GRASS GIS to generate attractive and reasonably realistic streams based on that elevation data and a not particularly sophisticated precipitation-evaporation model. I'm trying hard to do my part in promoting the use of sophisticated open-source GIS tools in worldbuilding. Part of that is sharing what I have learned in my own hobby pursuits with these tools.

An overview of the entire continent, showing the somewhat oversized desert regions, and poorly displaying the generated river network, below.


Here is a closer view of the central region to show the rivers better, particularly the ones ranging from the somewhat moister highlands through the desert.


Here is a closer view of the moister northern region.


Finally, here is an image showing the far south end of the continent. It features both the driest parts of the extensive desert regions and the wet, yet extremely rugged tropical southern peninsula.


I hope that you will find this useful and that it will spur more people to explore the use of these tools and share their own discoveries.

su_liam aka The Astrographer