MoT-Voellmy v. 2025-05-20

This new version fixes one important bug in the code (see closed Issue #1), provides an executable also for Apple Macintosh computers, updates the documentation, and provides several new examples. Users are urged to switch to the new version and discard the old one.

The bug fix concerns the term quantifying extra friction due to the centrifugal force. If curvature effects are turned on in the simulation configuration file, the run-out distance in the old version was almost identical to that without this term. In the new version, it will be shorter than without curvature effects. In typical avalanches, the differences will be a few tens of meters, but it can amount to several hundred meters if the avalanche attains very high speed. This can be seen very clearly in one of the example cases—drawn from the ISeeSnow model intercomparison initiative of the AvaFrame development team at BFW Innsbruck: Run the simulations 1HS_03_null75s_MoT-Voellmy.rcf and 1HS_03_curv75s_MoT-Voellmy.rcf (in the directory ./Examples/2023_ISeeSnow/data/CoulombOnly/Inputs/ and compare the results (for QGIS users, the QGIS project file ./IdealizedTopo.qgz may come in handy).

Full Changelog: v2025-02-10...v2025-05-20

MoT-Voellmy v. 2025-02-10

First public, open-source release of MoT-Voellmy, a simple and fast code for simulating the flow of (dense) snow avalanches over curved terrain. See the README file for a brief summary of the main features of the code and the documentation for more details on the mathematical and physical background as well as on how to run simulations.

The release provides the source code and executables for Linux and MS Windows, a version for macOS will be added shortly. The Linux version has been tested on Lubuntu 22.04 and 24.04. On Ubuntu 20.04 or other distributions using the same or older versions of the C standard library, either try with the statically linked executable or recompile the code as

gcc -Wall -pedantic -o MoT-Voellmy.2025-02-10 MoT-Voellmy.2025-02-10.c -lm.

For questions and remarks, please send an e-mail to di@ngi.no.