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


Hydrological situation for December 2023

Figure 1. Exceedance of lowest discharge threshold level for December 2023
Figure 1. Exceedance of lowest discharge threshold level for December 2023
Figure 2. Exceedance of lowest water level threshold level for December 2023
Figure 2. Exceedance of lowest water level threshold level for December 2023
Figure 3. Classification of stations according to discharge historical data average percentile ranges for December 2023
Figure 3. Classification of stations according to discharge historical data average percentile ranges for December 2023

During the month of December, there were 415 stations with exceedances, a hundred more than the previous month. Most of them are located in Germany (97 stations). In Slovenia there are 52 stations with exceedances and in Italy there are 41 stations. 

In addition, there are 34 stations in Poland, 26 in Croatia, 22 in Hungary and 20 in Spain. The following countries have recorded less than 20 stations with exceedances this month: Switzerland, Czech Republic, Ireland, Austria, Slovakia, Serbia, Ukraine, Norway, Bosnia and Herzegovina, Belgium, Sweden, Romania, Lithuania, France, and Iceland.

As for the river basins, the main river basin with values above the thresholds this month is the Danube River, with 184 stations in eleven different countries with Slovenia standing out. The Rhine River, focused in Germany and Switzerland, is the next river basin with the highest number of stations (53), followed by the Po River basin with 39 stations showing exceedances in Italy. A total of 48 different river basins have exceedances in December.

In terms of stations that recorded values of mean discharge above the 90% quantile, 331 exceeded this threshold this month. In December, Germany was the country with the most stations in this situation: 102. Poland, with 44 stations, and Austria with 28, are the countries with the next highest number of stations in this situation. The German stations are distributed in four different river basins, highlighting the Danube River and the Rhine River with 44 stations each exceeding this quantile. In Poland there are two basins affected (Oder and Vistula) while in Austria the Danube river and the Rhine river basins are affected. In Slovakia, 27 stations have values above this quantile. In Switzerland, 25 stations exceed this cliff. Other stations exceed the 90% quantile value in up to 21 countries.

By river basin, the aforementioned Danube River stands out with 146 stations above the 90% quantile. The  Rhine River basin is the second with the highest number of stations over this cliff, showing 69 stations in this situation and followed by the Oder river basin with 28. A total of 27 different river basins have exceedances over the 90% quantile in December.

Finally, and according to the number of stations recording mean values below the 10% quantile, in December there were 33 stations with average values below this cliff at five different countries.

This month, Spain is the country with most of the stations (20), followed by Norway with 8 stations and Romania with 3 stations. Sweden and Bulgaria show one station each in this situation.

In terms of river basin, this month the Guadalquivir River is the one with the highest number of cases, with 11 stations with an average discharge below the 10% quantile. The Llobregat River and the Danube River have 4 stations each, one more than the Ebro river basin. In total, as many as 15 different basins have values below this limit in Europe.