[R] netCDF to GeoTIFF by layer in r

Ahmed Attia ahmedatia80 at gmail.com
Wed Mar 28 17:38:14 CEST 2018


Hi Ben,

Adding 'band' to raster provided what I want;

importnetcdf <- raster(file.nc,band=4)
writeRaster(importnetcdf,file.tiff,"GTiff",overwrite=FALSE)

Thanks for your help.

Ahmed



Ahmed Attia, Ph.D.
Agronomist & Soil Scientist





On Wed, Mar 28, 2018 at 11:53 AM, Ben Tupper <btupper at bigelow.org> wrote:

> Hi Ahmed,
>
> When reading from a ncdf file you can use the 'varname', 'lvar' and
> 'level' arguments - see the 'Details' section in the docs
>
> https://www.rdocumentation.org/packages/raster/versions/2.6-
> 7/topics/raster
>
> We can't tell what is in the ncdf file from what you report other than it
> has 4 bands (layers) and that the first is called '
> Volumetric.water.content.at..33.kPa' If you want to know more about the
> what is in the file, then I suggest you use the ncdf4 package to open the
> file and explore it's contents - you should get a clear picture of it's
> contents from that.  Something like this (untested)...
>
> library(ncdf4)
> x <- nc_open(file.nc)
> x
> nc_close(x)
>
> While print lots of info about the file.
>
> Ben
>
> On Mar 28, 2018, at 10:37 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote:
>
> Hi
>
> I have a netCDF file of volumetric soil water content at four
> different soil layers and want to convert each soil layer in the
> netCDF file to a GeoTIFF layer. This code converts the netCDF file to
> one GeoTIFF layer, i.e. unclear which soil depth.
>
> file.nc <- "C:/Soil_Weather_data/Agro/VMC21/VMC21.nc"
>
> file.tiff <- "C:/Soil_Weather_data/Agro /VMC21/VMC21"
>
> importnetcdf <- raster(file.nc)
>
> importnetcdf
>
> class       : RasterLayer
> band        : 1  (of  4  bands)
> #the bands here are the four soil layers
> dimensions  : 16800, 43200, 725760000  (nrow, ncol, ncell)
> resolution  : 0.00833333, 0.00833333  (x, y)
> extent      : -180, 179.9998, -56, 83.99995  (xmin, xmax, ymin, ymax)
> coord. ref. : +proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0
> data source :
> C:\FAPSEP_Eucalyptus\FAPSEP\Soil_Weather_data\Agro_IBIS_Euca
> lipto\VMC21\VMC21.nc
> names       : Volumetric.water.content.at..33.kPa
> z-value     : 4.5
> zvar        : VMC2
>
>
>
> VMC1<-writeRaster(importnetcdf,filename="file.tiff",format="
> GTiff",overwrite=TRUE,bylayer=TRUE,suffix="1:4")
>   #bylayer=TRUE, did not work.
>
> VMC1
>
> class       : RasterLayer
> dimensions  : 16800, 43200, 725760000  (nrow, ncol, ncell)
> resolution  : 0.00833333, 0.00833333  (x, y)
> extent      : -180, 179.9998, -56, 83.99995  (xmin, xmax, ymin, ymax)
> coord. ref. : +proj=longlat +datum=WGS84 +no_defs +ellps=WGS84
> +towgs84=0,0,0
> data source : C:\Users\Ahmed\Documents\file.tif
> names       : file
> values      : 2, 80  (min, max)
>
> Any help!
>
>
> Ahmed Attia, Ph.D.
> Agronomist & Soil Scientist
>
> [[alternative HTML version deleted]]
>
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>
> Ben Tupper
> Bigelow Laboratory for Ocean Sciences
> 60 Bigelow Drive
> <https://maps.google.com/?q=60+Bigelow+Drive&entry=gmail&source=g>, P.O.
> Box 380
> East Boothbay, Maine 04544
> http://www.bigelow.org
>
> Tick Forecasting: https://eco.bigelow.org/
>
>
>
>
>

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