by EFAS Hydrological Data Collection Centre
During the month of April, there were 116 stations with exceedances, similar to the previous month. The majority of stations with exceedances are in Ukraine and Croatia (14), all of them related to water level. In Germany, there are 10 stations with exceedances in both variables. Serbia also stands out with exceedances at 10 stations.
In addition, there are station exceedances in the Czech Republic (9), Italy (8), Bosnia-Herzegovina (8), Poland (7), and Spain (6). Several countries have recorded less than five exceedances this month: Austria and Slovenia (4), Slovakia, Iceland, Norway, Hungary and Romania (3), Belgium (2), and only one station with values above the threshold on Israel and Ireland.
As for the river basins, the main river basin with values above the threshold is again the Danube, with 51 stations in 11 different countries, with Croatia and Serbia standing out with 13 and 10 exceedances respectively. The Rhine River in Germany and Austria is the next river basin with the highest number of stations (12). A total of 28 different river basins have exceedances in April.
In terms of the stations that recorded values of mean discharge above the 90% quantile, 114 exceeded this threshold in April, more than twice as many in the previous month. In April, England was the country with the most stations in this situation (23), ten times more than in March. Luxembourg, with 16 stations in this situation, and Germany with 14, are the countries with the next highest number of stations. The British stations are distributed in six different basins, highlighting the Thames River, with 16 stations in this situation. In Luxembourg, only the Rhine basin is affected, while in Germany we find three basins, also highlighting the Rhine basin. In Spain, 10 stations show values above this quantile. In Norway, eight stations exceed this cliff. Other stations exceed the 90% quantile value in up to 14 countries.
By river basin, it is the Rhine River that stands out with 26 stations above the 90% quantile. The Danube river basin is the second with the highest number of stations over this cliff, showing twenty stations in this situation and followed by the aforementioned Thames with 16. A total of 34 different river basins have exceedances over the 90% quantile in April.
Finally, and according to the number of stations recording mean values below the 10% quantile, we can find an increase of nearly fifty percent. In the month of April, there were 79 stations with average values below this cliff, but in fewer countries, only eight.
Again this month, Spain is the country with the most stations (59), followed by France with seven stations. Italy has six stations with values below this threshold. With two stations we find Austria and Poland, while Romania, Switzerland, and Norway have only one station each in this situation.
In terms of river basin, this month the Ebro is the river with the highest number of cases, with 21 stations with an average discharge below the 10% quantile. The Duero, Guadalquivir, and Llobregat rivers have more than five stations each in the same situation. All these basins are located in Spain, where seven other rivers are affected. In total, as many as twenty-three different basins have values below this limit in Europe.