Hi,
I’d like to use the conditioned DEM from HydroSheds (15sec resolution)
in GRASS to extract rivers etc. using r.watershed. On the HydroSheds-
Website (http://hydrosheds.cr.usgs.gov/dataavail.php) there are two possible
file formats: bil and esri grid.
The esri grid folder for Europe (eu_dem_15s) contains several files all with .adf ending and metadata (htm, xml).
The bil folder contains the eu_dem_15s.bil and a *.hdr and *.prj and some more.
Which format is prefered for importing into GRASS? I guess its the .bil as there is only
one bil-file with the different addtional info (header, projection etc.). Which format type
is the .bil in r.in.gdal?
/Johannes
Johannes Radinger wrote:
Hi,
Hi Johnanes!
I'd like to use the conditioned DEM from HydroSheds (15sec resolution)
in GRASS to extract rivers etc. using r.watershed. On the HydroSheds-
Website (http://hydrosheds.cr.usgs.gov/dataavail.php) there are two possible
file formats: bil and esri grid.
The esri grid folder for Europe (eu_dem_15s) contains several files all
with .adf ending and metadata (htm, xml).
The bil folder contains the eu_dem_15s.bil and a *.hdr and *.prj and some
more.
Which format is prefered for importing into GRASS? I guess its the .bil as
there is only
one bil-file with the different addtional info (header, projection etc.).
Which format type
is the .bil in r.in.gdal?
I guess (BIL is simply, well as we all know, "Binary Data Interleaved per
Line", and) what matters is to have beforehand a Header file (the .hdr). It
might be ESRI's "EHdr -- ESRI .hdr Labelled" type of file or ENVI's "ENVI -
ENVI .hdr Labelled Raster".
# check...
gdalinfo --formats | grep .hdr
ENVI (rw+v): ENVI .hdr Labelled
EHdr (rw+v): ESRI .hdr Labelled
..
Also, what does "gdalinfo" on the "*.hdr" files of yours say about?
Importing should be straightforward using "r.in.gdal".
...ok, looking closely: I've downloaded one of the files:
<http://earlywarning.usgs.gov/hydrodata/sa_15s_zip_bil/ca_dem_15s_bil.zip>\.
#unzip, checking
gdalinfo ca_dem_15s.bil -nogcp -nomd -nofl
Driver: EHdr/ESRI .hdr Labelled
Files: ca_dem_15s.bil
Size is 14160, 6000
Coordinate System is:
[...]
I think it should be easy to import.
Best, Nikos
/Johannes
[0] <http://www.gdal.org/frmt_various.html>
On Saturday 18 of May 2013 15:44:47 Nikos Alexandris wrote:
..
Also, what does "gdalinfo" on the "*.hdr" files of yours say about?
Well, right... the *.bil file(s) as shown below.
..
#unzip, checking
gdalinfo ca_dem_15s.bil -nogcp -nomd -nofl
Driver: EHdr/ESRI .hdr Labelled
Files: ca_dem_15s.bil
Size is 14160, 6000
Coordinate System is:
[...]
Nikos
Hi Nikos,
thanks! I already also checked and its really straight forward to import the bil raster file as ESRI-rasters.
Now I am just working on a re-projection e.g. to a pseudo-mercator system… but that is another story 
/johannes
···
On Sat, May 18, 2013 at 2:46 PM, Nikos Alexandris <nik@nikosalexandris.net> wrote:
On Saturday 18 of May 2013 15:44:47 Nikos Alexandris wrote:
…
Also, what does “gdalinfo” on the “*.hdr” files of yours say about?
Well, right… the *.bil file(s) as shown below.
…
#unzip, checking
gdalinfo ca_dem_15s.bil -nogcp -nomd -nofl
Driver: EHdr/ESRI .hdr Labelled
Files: ca_dem_15s.bil
Size is 14160, 6000
Coordinate System is:
[…]
Nikos
On Sat, May 18, 2013 at 1:55 PM, Johannes Radinger
<johannesradinger@gmail.com> wrote:
Hi,
I'd like to use the conditioned DEM from HydroSheds (15sec resolution)
in GRASS to extract rivers etc. using r.watershed.
Various artifacts were introduced in the conditioned DEMs of
HydroSheds. Rather use the filled, but not conditioned DEMs,
particularly when you want to use r.watershed or r.stream.extract. The
results will be more realistic. Or to be 100% sure, use SRTM v2.1 and
fill nodata with GRASS.
On the HydroSheds-
Website (http://hydrosheds.cr.usgs.gov/dataavail.php) there are two possible
file formats: bil and esri grid.
The esri grid folder for Europe (eu_dem_15s) contains several files all with
.adf ending and metadata (htm, xml).
The bil folder contains the eu_dem_15s.bil and a *.hdr and *.prj and some
more.
You should download both and investigate the output of gdalinfo for
both. One of them might have wrong extents and resolution. For
example, worldclim also provides the same two file formats: bil and
esri grid. In this case, the esri grid is wrong and the bil format
should be used (ESRI has problems with coordinate precision).
Markus M
Which format is prefered for importing into GRASS? I guess its the .bil as
there is only
one bil-file with the different addtional info (header, projection etc.).
Which format type
is the .bil in r.in.gdal?
/Johannes
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