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


Hydrological situation for August 2023

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

by EFAS Hydrological Data Collection Centre 

During the month of August, there were 288 stations with exceedances, five times that of the previous month. Most of the stations are located in Slovenia (83 stations), related to both types of variables (water level and discharge). In Austria, there are 47 stations with exceedances. In Norway and Germany, there are 38 and 37 stations respectively. 

In addition, there are 24 stations in Italy and 21 in Croatia. The following countries have recorded ten or less stations with exceedances this month: Switzerland (10), Sweden (9), Hungary (7), Slovakia (6), Poland (3), Spain (2) and Serbia (1).

As for the river basins, the main river basin with values above the threshold is again the Danube, with 184 stations in eight different countries, with Slovenia standing out with 71 exceedances. The Po River in Italy is the next river basin with the highest number of stations (23), followed by the Glomma River and the Rhine River, both with 13 stations showing exceedances. A total of 38 different river basins have exceedances in August.

In August 326 stations recorded values of mean discharge above the 90% quantile. Slovenia was the country with the most stations in this situation with 112 presented. The countries with the next highest number of stations in this situation are Norway (48), Croatia, and Germany (25 each). The Slovenian stations are distributed in ten different basins, highlighting the Danube River, with 82 stations exceeding this quantile. In Norway, there are 14 basins affected while in Germany and Croatia, we find three basins on each country. In Sweden, 21 stations have values above this quantile. In Spain, 17 stations exceed this cliff. Other stations exceed the 90% quantile value in up to 18 countries.

By river basin, the Danube River stands out with 144 stations above the 90% quantile. The  Soca-Isonzo river basin (Slovenia) is the second with the highest number of stations over this cliff, showing 19 stations in this situation, followed by the Rhine river basin with 18. A total of 74 different river basins have exceedances over the 90% quantile in August.

Finally, and according to the number of stations recording mean values below the 10% quantile in August, there were 71 stations with average values below this cliff in 14 different countries.

This month, Spain is the country with most of the stations (28), followed by Poland with 12 stations. France has 11 stations with values below this threshold. With five stations we find Romania, Iceland, and Norway with three each. Ukraine has two stations with mean values lower than this cliff and another seven countries show one station each in this situation.

In terms of river basin, this month the Ebro River is the one with the highest number of cases, with 11 stations with an average discharge below the 10% quantile. The Danube River has nine stations, and the Vistula, the Loire, and the Guadalquivir rivers have seven stations each in the same situation. In total, as many as twenty-five different basins have values below this limit in Europe.