Hi Priscilla,

I guess the problem is that you run g.region both with the –a flag and the 
align option.
Se: https://grass.osgeo.org/grass70/manuals/g.region.html

Please try:
g.region -p raster=out_Ghiandone_DEM_strahler@Silvia 
or even just:
g.region -p raster=out_Ghiandone_DEM_strahler@Silvia
(both commands should give the same result).

I have seen quite some confusion around the –a flag (e.g. it has been used in 
Processing in QGIS in a unsuitable way for quite some time).
Maybe the manual should be improved by:

1)      altering the flag description and

2)      adding examples for aligning the region to

a.      another raster map

b.      a user given resolution / map resolution

Flag description could be e.g.:
“Adjusted to be even multiples of the resolution in raster or res option” 
instead of the current:
“Align region to resolution (default = align to bounds, works only for 2D 

BTW, is there any case where it makes sense to specify both –a flag and align 
option? If not, both could be made mutually exclusive in order to avoid such 

Finally, two possible examples for the manual of g.region, which might help to 
make that a bit more clear:

# Set region extent to a vector map and align resolution to an existing raster 
g.region –p vector=soils align=elev_state_500m

# Define region to  align resolution to be an even multiple of the resolution 
specified by the user
g.region –pa vector=soils res=100

Kind regards,

From: grass-user [mailto:grass-user-boun...@lists.osgeo.org] On Behalf Of 
Margherita Di Leo
Sent: 13. oktober 2016 18:18
To: Priscilla_I <isacco.sil...@gmail.com>
Cc: GRASS user list <grass-user@lists.osgeo.org>
Subject: Re: [GRASS-user] Problem in running r.basin


On Thu, Oct 13, 2016 at 4:51 PM, Priscilla_I 
<isacco.sil...@gmail.com<mailto:isacco.sil...@gmail.com>> wrote:
I'm a new grass user, running "r.basin" module for Grass 7.0.4 on Windows
10, I get this error message "ERROR: Region resolution and raster map
<out_Ghiandone_DEM_strahler> resolution differs. Run 'g.region
raster=out_Ghiandone_DEM_strahler' to set proper region resolution."
I'm using a map in projected coordinates, and I align region with the raster

g.region -p -a raster=out_Ghiandone_DEM_strahler@Silvia

projection: 1 (UTM)
zone:       32
datum:      wgs84
ellipsoid:  wgs84
north:      4965768.6398801
south:      4943886.74090327
west:       353479.72655961
east:       379279.66825865
nsres:      24.64177813
ewres:      24.64177813
rows:       888
cols:       1047
cells:      929736

raster info are

Map:      out_Ghiandone_DEM_strahler@Si  Date: Thu Oct 13 11:31:23 2016    |
 | Mapset:   Silvia                         Login of Creator: Silvia
 | Location: Piemonte
 | DataBase: C:\Users\Silvia\Desktop\Grass
 | Title:     ( out_Ghiandone_DEM_strahler )
 | Timestamp: none

 |   Type of Map:  raster               Number of Categories: 0
 |   Data Type:    CELL
 |   Rows:         888
 |   Columns:      1047
 |   Total Cells:  929736
 |        Projection: UTM (zone 32)
 |            N: 4965768.6398801    S: 4943886.74090327   Res: 24.64177813
 |            E: 379279.66825865    W: 353479.72655961   Res: 24.64177813
 |   Range of data:    min = 1  max = 4
 |   Data Description:
 |    generato da r.stream.order
 |   Comments:
 |    r.stream.order stream_rast="out_Ghiandone_DEM_stream_e" direction="o\
 |    ut_Ghiandone_DEM_drainage_e" strahler="out_Ghiandone_DEM_strahler" h\
 |    orton="out_Ghiandone_DEM_horton" shreve="out_Ghiandone_DEM_shreve" h\
 |    ack="out_Ghiandone_DEM_hack" memory=300


Any ideas? Thanks in advance!

What is the exact r.basin command line that you  run? Can you post also 
r.info<http://r.info> of the DEM that you use as input?

Margherita Di Leo
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