FOSS4G-Asia 2023 Seoul

This talk introduces a new open-source fast Memory-Efficient Flow Accumulation (MEFA) algorithm using OpenMP parallelization. Flow accumulation is one of the most important parameters for any hydrologic and/or environmental analyses. There have been many studies that focus on the improvement of its computational efficiency using OpenMP, MPI, and CUDA, but most of benchmark algorithms are not memory-efficient in terms of the number of write operations and the amount of bytes read/written. This memory-inefficient nature of those algorithms deteriorates their computational performance during parallel processing of the input flow direction matrix. The new MEFA algorithm has reduced its memory requirements in both writes and bytes by eliminating a need for intermediate output matrices and writing its final value to each cell only once deterministically. The new algorithm performed 45% and 19% faster than its OpenMP and MPI benchmark algorithms, respectively, using 20% less memory asymptotically.

The GRASS GIS community celebrated its 40th birthday this past summer! Its version 8.3 provides more than 360 changes compared to the 8.2 release, and it comes with many fixes and improvements in its modules and graphical user interface. The single-window layout is now mature and provided as the default UI. We have extensively cleaned up the C/C++ code by adopting the Clang format and fixing almost all compiler warnings. Not only that, we started modernizing the build system using CMake for cross-platform build automation, testing, and packaging. We are also converting the HTML manuals to easier-to-maintain Markdown/mkdocs to collect more user contributions. Last but not least, for internalization efforts, we have migrated our translation platform from Transifex to Weblate, which automatically creates pull requests with new translations. As always, we welcome new contributors for development, documentation, and translation!