[GRASS-user] Import conditioned DEM from HydroSheds

[Nikos Alexandris]

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>