Opening CHIRPS' NetCDF file in QGIS

Question

I'm trying to open a NetCDF file from the CHIRPS dataset with yearly precipitation in QGIS 2.14 (OsX) but it hasn't worked at all. I've tried using both the NetCDF browser plugin and opening the NetCDF as raster file (common way of doing it) but according to QGIS all the raster values in the dimension (years) are 0 (no rain). I thought it was an error in the NetCDF but I opened it in ArcMap and it shows all the different values of rain per year pretty well.

Does any of you had this same experience in QGIS with NetCDFs from other sources than CHIRPS? I wonder if it is a bug in GDAL or some very specific characteristic of the type of NetCDF file that the CHIRPS folks are exporting.

Any help or comments are welcome!

Answer 1

Taking the global annual data it seems that qgis does not read the metadata.

With gdalinfo, you get this information:

Size is 7200, 2000
precip_geostatial_lat_max=50 
precip_geostatial_lat_min=-50 
precip_geostatial_lon_max=180 
precip_geostatial_lon_min=-180 
precip_long_name=Climate Hazards group InfraRed Precipitation with Stations
precip_missing_value=-9999 

Comparing size and extent, the resolution seems to be 20pix per degree. This can be used to build a vrt file around the netcdf:

gdal_translate -of VRT -a_ullr -180 -50 180 50 -a_srs EPSG:4326 -a_nodata -9999 -b 1 chirps-v2.0.annual.nc chirps.vrt

to get a reasonable output compared with Natural Earths boundaries:

Note that "upper left" is not where you expect it, because the file is upside down.

The QGIS netcdf plugin shows values that do not make sense for me. It should report -9999 for nodata in sea areas, but does not. It is still experimental after all.