Dear all,
I tried to extract a river network from a huge DEM:
rows: 180752
cols: 141312
cells: 25542426624
r.watershed (in an older revision of GRASS 7) had no problem with the DEM and created raster streams very nicely. However, I could not convert them to vector because r.to.vect complained the streams weren’t thinned properly. Since I would like to continue with the other r.streams.* addons anyway, I tried running r.stream.extract. On the entire DEM it failed with the error message below:
(Mon Apr 13 23:21:30 2015)
r.stream.extract --verbose elevation=dem_10m_nosefi_float@PERMANENT accumulation=dem_10m_nosefi_float_accum@Hydrologi threshold=1500 stream_length=5 memory=50000 stream_raster=dem_10m_nosefi_float_streams_ids stream_vector=dem_10m_nosefi_float_streams_ids
4.23% of data are kept in memory
Will need up to 1285.49 GB (1316340 MB) of disk space
Creating temporary files…
Loading input raster maps…
ERROR: Unable to load input raster map(s)
(Wed Apr 15 12:44:30 2015) Command finished (2243 min 0 sec)
From the error message (Unable to load input raster map(s)), I have no idea where I could start searching for the problem…
On a smaller catchment (with all in RAM calculation) r.stream.extract works fine…
Any ideas how to fix this? Running r.stream.extract per catchment (delineated earlier with r.watershed) would be a possible workaround…
Cheers
Stefan