Aggregation of weather indicators

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General description

The aggregation of grid weather towards administrative regions is executed for different input datasets. For each of the datasets the procedure is repeated using different weighing methods and different output resolutions. A dedicated software package called Aggregator is developed to do all calculations.

Input datasets

In the MCYFS several grid weather datasets are available: grid weather based on station observations (observed grid weather) and 6 ECMWF products (see acquisition). All sets are available in grid format. A selection of these datasets is aggregated to regions: observed grid weather (table WEATHER_OBS_GRID) and (re-)forecasted weather of the ERA, HIS/OPE model (table WEATHER_<MODEL>_GRID).

Weighing methods

Grid cells (or part of grid cells) that fall inside a region are used to calculate the aggregated value of a specific weather indicator. Besides using all grid cells in a region, the aggregation is repeated using different selections of grid cells in each region. The selection is based on landcover masks. In other words: the aggregated indicator emphasizes the phenomena that are most relevant for the selected mask while neglecting the phenomena not relevant for the selected mask.

Masks

For Europe weather data is aggregated to land cover types only:

  • no mask (all mixed)
  • agricultural areas
  • non-irrigated arable land
  • arable land
  • pasture
  • temporary forage
  • rice

The masks are based on CORINE land cover and for countries, not covered by CORINE, the Globcover data set is used.


For the other regional windows weather data is aggregated to land cover types and a few crop types, the latter based on crop specific areas available at regional level.

RUK CHN IND SAM
no mask, all mixed no mask, all mixed no mask, all mixed no mask, all mixed
irrigated cropland irrigated cropland irrigated cropland
rain fed cropland rain fed cropland rain fed cropland rain fed cropland
arable Land (irr+rainfed) arable Land (irr+rainfed) arable Land (irr+rainfed) arable Land (irr+rainfed)
agricultural areas (arable + mosaic > 50%) agricultural areas (arable + mosaic > 50%) agricultural areas (arable + mosaic > 50%) agricultural areas (arable + mosaic > 50%)
arable land custom arable land custom
winter wheat irrigated wheat wheat
spring wheat rain fed wheat irrigated wheat
grain maize rice rain fed wheat
rice


Output resolutions

The output is calculated for different types of regions.

In case of Europe:

  • 4 levels of administrative regions (NUTS0-3)
  • 2 levels of agri-environmental regions (zones and strata)

In case of other regional windows like Russia and Kazakhstan (RUK), China (CHN), India (IND) and South America (SAM):

  • 3-4 levels of administrative regions (RUK has a specific sub national level grouping level 1 regions)

The results are written to the tables

Replace <MODEL> with one of the model abbreviations for which aggregated indicators are calculated (ERA, HIS/OPE).