To use simulated crop indicators in the Yield Forecasting module - where they are compared to officially reported yields per region - they have to be aggregated to administrative regions. Administrative regions in Europe are called regions. The NUTS system is organized in different levels. The highest level is made up of countries and referred to as level 0 regions. Countries are subdivided in macro regions (level 1). Macro regions are subdivided in sub-regions (level 2). Level 3 regions form the finest sub-division. The administrative regions and there relations are stored in the REGION table.
Some countries are too small to split up to the finest level (level 3). In that case the region level 3 is equal to region level 2 in order to have a complete coverage within each level. Some of the smallest countries are not subdivided and region level 1, 2 and 3 are duplicates from region level 0. Regions that fall inside the MCYFS region of interest but are not part of the European Union don't have a formal NUTS divisions. Most of these regions only have one subdivision (region level 1) which is duplicated to level 2 and 3 to cover the entire MCYFS region of interest with each level.
Acreage statistics of regions is used to aggregate simulated crop indicators from the finest level3 to higher levels (2, 1 and 0). The acreage is stored in table AGGREGATION_AREAS. By using alternative aggregation area's, a single simulated crop is aggregated towards various alternative crops (see Crop parameters for the CGMS), each of which can be used in the Yield Forecasting.See EMU to administrative regions for the construction and application of the AGGREGATION_AREAS table.