Writing data to shapefile's attribute table from NetCDF

[Solhailu]

I have a shapefile (lines) and netcdf file both linked with netid. The netcdf has two dimensions (time and netid) one variable (Qout). The netcdf file has a time series of about 40 years and need to compute a trend and export the data into the shapefile for plotting in ggplot using the values in the attribute table (using something ggplot(shp) + geom_sf(aes(colour = shp$Duration))).

  dimensions:
         time = UNLIMITED ; // (12784 currently)
         netid = 716862 ;

variables:
     float Qout(time, netid) 

The trend is based on the Mann-Kendall test.

  Rs=ts(s,start=1979)
  mk.test(Rs)
  sens.slope(Rs)

Please let me know if you have any idea how to create a loop reading the Qout for each netid and wrtite the mk.test and sens.slope to the shapefile based its netid.

Best regards,

Solomon