Monthly maps for discharge anomalies and Lowest alert level exceedance with a summary of the monthly hydrological situation.


Hydrological situation for December 2021

Figure 1. Exceedance of lowest discharge threshold level for December 2021.
Figure 1. Exceedance of lowest discharge threshold level for December 2021.
Figure 2. Exceedance of lowest water level threshold level for December 2021.
Figure 2. Exceedance of lowest water level threshold level for December 2021.
Figure 3. Classification of stations according to discharge historical data average percentile ranges for December 2021.
Figure 3. Classification of stations according to discharge historical data average percentile ranges for December 2021.

by EFAS Hydrological Data Collection Centre

During the month of December, the highest concentration of stations with exceedances is found mainly in the north of Spain, especially in the Ebro river basin and in a smaller number of stations in the Douro, Minho, Llobregat, Ter, Turia, Seco, and Algar basins. There is also a large number of stations that overpass their first threshold in Bosnia and Herzegovina, Croatia, and Slovenia (Danube river basin), and in northern and central Italy (Po, Tiber, Garigliano, and Badino basins). In the Danube river basin, there are more dispersed stations with exceedances in Serbia, Romania, Ukraine, Hungary, Austria, and Slovakia. There are also notable stations located in the Dnieper and Neman basins (Belarus and Lithuania), the Vistula, Oder, and Elbe basins (Poland and Germany), in the Rhine basin in Germany, and in the Scheld basin in Belgium. There are some exceedances too in center Norway, Ireland, and Iceland.

Regarding stations registering values above the 90% quantile, the more remarkable place is the Scandinavian Peninsula: Norway, Finland, and Sweden with 24, 10, and nine stations, respectively. In Spain, 21 stations exceeded the 90% quantile, mainly in the Ebro and Guadalquivir basins, and to a lesser extent in Jucar, Mijares, Seco, Algar, and Barbate basins. Along the Danube river basin, 12 stations throughout the following countries overpassed the quantile: in Germany, Austria, Romania, Bosnia and Herzegovina, Serbia, Bulgaria. In a more isolated way, there are also some stations registering values above the 90% quantile in Ukraine, Belarus, Poland, Italy, and France.

Finally, and according to those stations registering values below the 10% quantile (38 in total), the highest concentration of them corresponded to the Danube basin, mainly the western area (Austria). Only one station is located in Hungary and another one in Serbia. Secondly, we also have a high density of stations fulfilling this criterion in Spain (Ebro, Guadalquivir, Guadalhorce, and Verde basins) and in central Italy. Finally, a lower density of stations under the 10% quantile occurred in Ukraine, Poland, Scandinavia, Germany, Iceland, and the United Kingdom.