State of GRASS GIS

Martin Landa
& Markus Neteler, Verónica Andreo, Vaclav Petras, Anna Petrasova, Ondrej Pesek, Linda Karlovska


FOSS4G 2023 - Prizren, Kosovo

About the presenter...

  • Department of Geomatics, Faculty of Civil Engineering,
    Czech Technical University in Prague (CZ)
  • PhD in Geodesy and Cartography
  • FOSS4G enthusiasts, a freelance programmer
  • Since 2003 active in the GRASS GIS project Contribution to GRASS GIS Pic of Martin Landa

For newcomers: what is GRASS GIS?

  • GRASS GIS (Geographic Resources Analysis Support System), a FOSS suite used for geospatial data management and analysis, image processing, spatial modeling, and visualization.
  • Originally developed by the U.S. Army CERL for land management and environmental planning (1982-1995).
  • Founding member of OSGeo (2006)
  • 40 years of continuous geospatial development
GRASS GIS Community Meeting 40th birthday
GRASS GIS 40th birthday

All-in-one software suite

  • All matured tools available right away
  • Download of experimental tools possible
  • Network analysis, hydrology, remote sensing, vector topology, time series, …



  • 8.2.0, Jun 2022 Presented on FOSS4G 2022.
  • 8.2.1, Jan 2023 Stability and fixes.
  • 8.3.0, Jun 2023 Single window interface as the default.
    • major.minor.micro – semantic versioning:
      • major (x) brings features and possibly backward incompatible changes
      • minor (x.y) brings features and fixes,
      • micro (x.y.z) brings fixes,
    • RFC: Version Numbering
GRASS GIS splash screen

Exciting new features in GRASS 8.3+

GRASS 8.3.0 news

Skeletons and Centerlines

v.voronoi tool can now create area skeletons and centerlines. GRASS GIS and vector skeletonising

by Markus Metz

Soil line slope support for vegetation indices

Adding the possibility to define the soil line slope for indices in

PVI with soil line slope 0.80 PVI with soil line slope 0.99

In the picture: Comparison of PVI computed with soil line slope 0.80 (left) and 0.99 (right).

by Ondrej Pesek

PyWPS export in GRASS GIS modeler

gmodeler model PyWPS logo PyWPS export

Automatic export of GRASS GIS models as PyWPS scripts. More info in the documentation.

by Ondrej Pesek

Improved Jupyter Notebooks integration

Python library grass.jupyter for easy and interactive visualization in Jupyter notebooks.

GRASS GIS and viewshed time series GRASS GIS and viewshed

by Caitlin Haedrich, Vaclav Petras, Anna Petrasova

Faster External Data Links

r.external links (opens) external raster data (GeoTiffs, …) faster.
(2-5× faster, or almost no time for some workflows)
GRASS GIS and external file linking

by Markus Metz

Great for workflows when only portion of the data is processed in GRASS GIS.

Streamlined C and C++ code maintenance

  • All GCC -Wall -Wextra warnings fixed
  • Clang-Format applied
  • Warnings and formatting checked in CI
code in qt creator

by Nicklas Larsson

More parallelization in GRASS 8.3

New in GRASS GIS 8.3

Parallel C tools (OpenMP)

  • r.univar
  • r.resamp.interp
  • r.resamp.filter

Parallel Python tools

  • t.rast.univar
  • t.rast3d.univar
GRASS GIS and openMP

+ fixes in other parallel tools and benchmarks

by Aaron Saw Min Sern, Stefan Blumentrath and Anna Petrasova

More parallel tools

  • Core tools: r.series, r.neighbors, r.patch, r.mfilter, r.slope.aspect, r.sun,, r.sim.sediment, r.sim.water
  • Addon tools: r.sun.daily,, r.mapcalc.tiled, t.rast.what.aggr, r.connectivity.corridors, r.viewshed.exposure, and 14 more
  • Parallelizing custom Python scripts:
    • Data parallelization: GridModule
    • Task parallelization: multiprocessing, ParallelModuleQueue
Data and task based parallelization

A better GUI experience in GRASS

Improved First-time User Experience in GRASS 8

Old start of GRASS GIS 7 Old start of GRASS GIS 7 no more

Improved First-time User Experience in GRASS 8

Initial project sets up automatically. Guidance provided for next steps.
GRASS GIS 8 welcome

by Linda Karlovska & rest of the community (many reviews, calls, user surveys, …)

Single-Window GUI in GRASS 8.2+

  • One GUI window with optimized layout with dockable widgets.
  • Default in 8.3+
  • Many improvements and fixes to support various platforms
GRASS GIS and single window GUI

by Linda Karlovska

Improving Single-Window GUI user experience - GRASS mini project 2023

  • Undocking map display notebook page
  • New layout of the Console pane
Undocked map display notebook page

by Linda Karlovska

Dark Theme Support

  • Interface respects system dark theme.
  • New: fixes for Graphical Modeler

GRASS GIS and dark theme

by Anna Petrasova, Nicklas Larsson, Martin Landa

Selected addons contributed by the community

GRASS GIS Meeting 2023 in Prague

Hydro-flattening a DEM

r.hydro.flatten derives single elevation value for water bodies based on lidar data.
hydro-flattened DEM

addon by Anna Petrasova

Random walk simulation

r.random.walk generates a 2D random walk with multiple parallel walkers and different walker's behavior.
example example

addon by Corey White

Boxplots in space-time raster data set

t.rast.boxplot draws boxplots of the raster in a space-time raster data set.
t.rast.boxplot example t.rast.boxplot example

addon by Paulo van Breugel

Thredds Data Server

m.crawl.thredds crawls the catalog of a Thredds Data Server (TDS) starting from the catalog-URL. It is a wrapper module around the Python library thredds_crawler.


addon by Stefan Blumentrath

Get involved! Your contribution is welcome!

GRASS GIS Meeting in Prague 2023

Code contributions

GRASS GIS development is GitHub-centered: core, addons, website

  • Fill bug reports or feature requests
  • All issues and PR's are publicly visible
  • Ask, comment, suggest also in Github Discussions
  • "Fork me on GitHub" and suggest changes or fix bugs via pull requests
  • Create your own addon! See this nice workshop for a guideline: How to write a Python tool for GRASS
GitHub logo

Other contributions are relevant too!

  • Translations: we use OSGeo Weblate
  • Documentation: start by fixing typos in manual pages, add examples where missing, create cool screenshots, write tutorials in the wiki, etc.
  • Contribute material for our social media
  • Write a blog post for our website
  • Bring your own ideas!

Sponsoring: how to...?

  • Individuals:
  • Organizations:
    • Time: employee time for new developments
    • Money: become a regular sponsor with annual contributions or pay developers (or companies) to add features or fix bugs
OpenCollective tiers

"One of the greatest benefits of GRASS GIS is that its environment gives us a plethora of options for manipulating data and testing/designing our automation/workflow processes."

Student grants program: coding for money!

  • GRASS GIS offers a limited number of student grants.
  • These can include actual coding, bug fixing, or documentation and the creation of educational resources.
GRASS GIS student grants

GRASS celebrated 40(!) in Prague

GRASS celebrates 40!

GRASS Community Meeting Prague 2023

GRASS users, supporters, contributors, power users and developers met from June 2 to 6, 2023 in Prague (CZ)

GRASS Meeting in Prague 2023

GRASS Community Meeting Prague 2023

Work and party
GRASS Meeting in Prague (work) GRASS meeting in Prague (party)

GRASS Community Meeting Prague 2023

Thanks to sponsors!!!

  • OSGeo (7300 USD), FOSSGIS (5000 EUR)
  • OSGeo Japan (550 USD) and many individials
  • Venue: Department of Geomatics, Faculty of Civil Engineering, Czech Technical University in Prague
OSGeo logo FOSSGIS logo
GRASS Prague Meeting Open Collectiveo

GRASS Community Meeting Prague 2023 - Selected outcomes

GRASS GIS 8.3 Release

  • More than 360 improvements and fixes!
  • See release notes on GitHub
release contributors

Progress in transition to CMake

  • Full build on UNIX environment
  • PR 3021
  • Thanks to Aaron Saw Min Sern, Loïc Bartoletti and others
cmake logo

New docker hub organization: mundialis -> OSGeo

GRASS GIS on OSGeo Docker Hub GRASS GIS on Docker Hub

by Carmen Tawalika (with support by Markus Neteler)

Graphical Modeler integrated in Single-Window

Graphical Modeler as a new window Graphical Modeler integrated in single window layout

by Martin Landa (work in progress PR 3003)

Conversion of the manual to Markdown/mkdocs

Initial work on conversion from HTML to Markdown/mkdocs

Goal: easier to maintain and more friendly to collect user contributions
GRASS GIS code manual in Markdown

by Markus Neteler

Conversion of the manual to Markdown/mkdocs

Initial work on conversion from HTML to Markdown/mkdocs

Goal: easier to maintain and more friendly to collect user contributions
GRASS GIS code manual in Markdown

by Markus Neteler

actinia export in GRASS GIS modeler

gmodeler model actinia logo actinia export

Automatic export of GRASS GIS models as actinia workflows/templates. Pull request #3005 hanging.

by Ondrej Pesek

Thanks for your attention!!



Bonus material

Land-use/Land-cover from Sentinel-2

r.incora is a multi-addon to derive LULC and change detection maps from S2 scenes incl. creation of training points from a set of rules.
Sentinel-2 based Land-use/Land-cover map

addon by mundialis, Germany

i.sentinel_2: new tools for Sentinel-2

  • i.sentinel_2.parallel.index: calculates different indices in parallel
  • i.sentinel_2.sen2cor: runs atmospheric correction on a single Sentinel-2 L1C scene using ESA's sen2cor
  • ... more to come.

addon by mundialis, Germany

i.svm: Add Support Vector Machines-based image classification

A pair of modules revealing most of features of libsvm to GRASS. Libsvm is a popular library used in many machine learning programs (including scikit-learn).

PR 2189 by Maris Nartiss