GRASS GIS categorical maps and legends

Did you ever add a legend to your categorical raster map in GRASS GIS that displayed many more categories than your map actually has? It can happen if that map was ‘cut out’ from a larger region using r.mapcalc. For example, if I have a vegetation map of eastern Africa, and I need one for Rwanda only. I would do something like: Continue reading

Vegetation map for eastern Africa 2.0

Check out the new vegetation map and accompanying tools for identifying and selecting the right tree for the right place in eastern Africa at

The potential natural vegetation (PNV) map of eastern and southern Africa covers the countries Burundi, Ethiopia, Kenya, Uganda, Rwanda, Tanzania, and Zambia. The first version of the map was developed by various partners in East Africa and Europe in 2010 and has now reached version 2.

The map is available in different formats and is accompanied by an extensive documentation of the floristic, physiognomic and other characteristics of the different vegetation types and useful woody species in the 8 countries.

The new map was launched yesterday at the XIV World Forestry Congress. ‪#‎Forests2015‬


Screenshot from 2015-09-09 16:50:19

Accessing shared files on Linux from Windows (trouble shooting / if solutions were always that simple)

The problem

I work in a shared Linux – Window environment and sharing files between computers has always been somewhat cumbersome. Most of the time I was able to access files in a shared folder on the Window machine from my Linux computer. But I never got it to work the other way around. The Windows computer simply did not see the shared folders on my Linux computer.

There are numerous blogs, email threads and forum articles dealing with similar problems. Solutions, if any, often involved tweaking Samba configuration. Alas, none ever worked for me. Continue reading

QGIS 2.10 Pisa is out!

The new QGIS 2.10 (Pisa) has been released, with many great new features, tweaks and enhancements. Check out the changelog for the highlights (you’ll need some time, it is again an impressive list of improvements and new features).

The source code and binaries for Windows, Debian and Ubuntu are already available via the large download link on the QGIS home page.  More packages will follow as soon as the package maintainers finish their work.

A big thanks to the developers, this is again an impressive piece of work!

First release candidate of the upcoming GRASS GIS 7.0.1 version is out

GRASS GIS 7.0.1 RC1 is the upcoming stability release and provides a series of stability fixes, manual improvements and a few language translations. This first release candidate GRASS GIS 7.0.1RC1 provides 168 fixes and improvements with respect to GRASS GIS 7.0.0. See here the announcement and further information.

If you want to help testing or just want to make sure to have all the latest improvements and fixes, go to the announcement page where you’ll find the download links for your system.

Another stab at creating a Tanaka-style contour map

In a recent post Anita Graser (aka underdark) showed how to create illuminated or Tanaka contours in QGIS using various functions available in the toolbox and some custom functions.

Here I want to explore a slightly different way to achieve the same, using GRASS GIS to compute the azimuth, brightness and line width. I’ll use the command line, but you can do the same using the menu in GRASS, or the corresponding GRASS functions in the QGIS processing toolbox.

Continue reading