Hello all I'm working on deriving a nice drainage network for the Amazon basin. The problem is that the area is too large.
The region settings are these: projection: 3 (Latitude-Longitude) zone: 0 datum: wgs84 ellipsoid: wgs84 north: 6:17N south: 21:30S west: 80:37W east: 44:50W nsres: 0:00:03 ewres: 0:00:03 rows: 33340 cols: 42940 cells: 1431619600 With 14.3 billion cels, r.watershed would need about 450 GiB of disk space running in seg mode, is that correct? (from the manual, 31 MB for 1 million cells). I do have that disk space available, but it's in a secondary drive. If I set TMPDIR to that drive, will r/watershed use it? I ask because the documentation (https://grass.osgeo.org/grass72/manuals/variables.html) only says that this environmental variable is used by "[Various GRASS GIS commands and wxGUI]". On a side note, r.terraflow should be an alternative for such a large dataset, but from the manual: "r.terraflow has a limit on the number of rows and columns (max 32,767 each)". That's the size of a positive short integer. Is this limit still needed? thanks Carlos -- Prof. Carlos Henrique Grohmann Institute of Energy and Environment - Univ. of São Paulo, Brazil - Digital Terrain Analysis | GIS | Remote Sensing - http://carlosgrohmann.com http://orcid.org/0000-0001-5073-5572 ________________ Can’t stop the signal.
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