Basins
The CEMS-flood sub-seasonal and seasonal products include a basin summary of the river discharge anomaly and uncertainty information. On this layer the basin colours represents the dominant forecast anomaly and uncertainty of the river pixels of the basins.
The basin delineation was done semi-automatically, including some manual corrections and subjective decisions on where to split very large catchments and how to group small river catchments along the coastal areas. The basin borders perfectly align with the 1 arcmin (~1.5 km) LISFLOOD river network in EFAS, while follow the 3 arcmin (~5 km) river network in GloFAS down to 250 km2 pixel size. Some basins are smaller while other are larger, generally smaller over EFAS, while larger outside of the EFAS domain. In addition, the basin size was often determined by the complexity of the river network and whether splitting larger basins made practical sense, i.e. not to create too small / too many basins, in case the river network complexity would have required it.
In total, 944 basins were defined globally (Figure 1a), of which 204 are within the EFAS domain (Figure 1b). The basin size ranges from yyy1 to yyy2 km2 globally, while zzz1 to zzz2 in EFAS, with the average size of XXX1 km2 in EFAS and XXX2 km2 in GloFAS.
Representative stations
GloFAS and EFAS have so-called fixed reporting points, which are used to show the forecast information regardless of conditions. These points are
