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


Hydrological situation for October 2021

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

During the month of October, the highest concentration of stations with exceedances is in the Po river basin (Italy), with 20 stations affected. The situation of exceedances in southern Norway and Sweden is also remarkable. In a more dispersed way, there are four stations with exceedances in Belarus (Dnieper, Neman, and Vistula river basins), one in Ukraine (Vistula river basin), one in Hungary (Danube basin), one in northern Poland, also in Germany, Slovenia, Croatia, and Bosnia & Herzegovina. Finally, 10 stations in Spain exceeded their thresholds, specifically in the east of the country (Llobregat, Ter, Besòs, Serpis, Seco, Almanzora, and Adra basins).

Regarding stations registering values above the 90% quantile, a small number of stations (72) exceeded this value in October. The majority of these stations were located in Scandinavian basins throughout Norway, Sweden, and Finland. Exceedances of the 90% quantile was also noteworthy Spain, where several basins in the east and south of the country had stations with values that were above the 90% quantile. To a lesser degree, other stations found with exceedances over their 90% quantile were located in the Dnieper basin, throughout Ukraine and Belarus, and in the Danube basin (crossing Bosnia and Herzegovina, Croatia, Germany, and Serbia). Isolated stations exceeding the 90% quantile occurred in stations in the Loire and Seine basins (France), Luxembourg (Rhine basin), Poland (Vistula basin), Belgium (Scheldt basin) and in England (Thames and Clyst basins).

Finally, regarding stations that registered values below the 10% quantile (38 in total), the highest concentration of them corresponded to the Danube basin, most prominently along the Austrian stretch of the river with seven stations highlighted. Also, in the Danube basin, we find three stations in Hungary and Ukraine, two stations in Romania, and a single station in Germany, Serbia, Slovakia, and Slovenia. In a more dispersed pattern, we find four stations around the border between France and Spain and four more in the Rhine basin in Germany. A lower density of stations under the 10% quantile occurred in southern Spain, the Oder basin in Poland, and the Dniester basin in Ukraine, with two stations each. At last, we can also find isolated stations fulfilling this criterion in the Tinnelva river (Norway), the Iijarvi river (Finland), the Aire river (France), the Attert river (Luxembourg) and the Parthe river in Germany.