Hi Nikos, On 2019-01-25 at 07:18 -0800, Nikos Alexandris <[email protected]> wrote... > A billion-pixel scaled DEM is the main input to compute the slope length > and steepness (LS) factor for RUSLE (`r.watershed`), only. > > Tiling this DEM in tiles of 5K^2 pixels (`r.tile`), appears to be a > reasonable approach to parallelise this process.
Do you need to parallelise it? I just ran r.watershed on a 4.5 billion-pixel DEM w/o a problem on my laptop and I think it took ~6 hours, but I'm not sure. It might have been closer to 12. I have 32 GB of ram and gave half to the process, but told it to use disk instead of memory via the -m flag: r.watershed -s -m elevation=phi threshold=1000000 drainage=dir memory=16384 --v --o -k. _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
