fitting new variograms using the up-to-date dwd weather data (here for precipitation)
DWD weather data is downloaded from https://opendata.dwd.de/climate_environment/CDC/observations_germany/climate/daily/more_precip/historical/
A comparison to the precipitation station data stored in /data/stohyd/data/processed/Germany/DWD/pre/pre_1900-2015/ to the new station data showed that some stations changed:
Nr Stations| Old LUT | New LUT | Same | Abandoned | New Stations
pre |5394 |5616 |5380 |14 |236
tavg |1059 |1213 |1055 |4 |158
tmax |1059 |1213 |1055 |4 |158
tmin |1059 |1213 |1055 |4 |158
However it is unclear which data was used for calculation of the variograms used in the current drought monitor version (status: 2019-11-28).
Calculation of the variogram resulted in the following theoretical variogram parameters (using exponential variogram type)
nugget sill range Type Easting Northing BIAS RMSE r
0.3199E+00 0.9526E+00 0.6429E+05 2 0.0 0.0 0.0098 0.0009 0.9946
The Old variogram parameters were:
nugget sill range varTyp
0.2000E+00 0.9014E+00 0.3990E+05 2
In the graph the new variogram is plotted using new theoretical and experimental variogram data)
Interestingly, the old nugget seems to fit the data better. The range is remarkable bigger in the new data. @thober any possible explanations?