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


Hydrological situation for January 2021

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

by EFAS Hydrological Data Collection Centre

January has been a month with abundant rain that has caused that many stations exceeded their threshold levels, especially in central Europe. The Danube basin stands out according to the number of stations affected - mainly in Germany, Romania, Serbia, Hungary, Bosnia & Herzegovina, and Slovenia. The Po river basin in Italy is second according to the number of stations with exceedances (35% of its stations exceeded threshold levels), although the percentage of stations in this basin with exceedances is 20% less than the Danube (which has a much larger area). The Rhine basin stands out in a third place with 20% of its stations with exceedances too. Other affected basins with more dispersed stations are the Oder, Vistula, and Dnieper river basins (in Poland, Czech Republic, Belarus, and Ukraine) and the Minho basin and Mediterranean and Levante areas (Spain). Finally, there are scattered stations in Norway, Sweden, Iceland, and even in Israel, where a station on the Jordan River overpassed their thresholds in the middle of January.

Regarding stations registering values above the 90% quantile, as was the case of the previous two months preceding, these are mostly located in the Scandinavian basins, where the vast majority of stations is located in the southern basins of Norway (Drammen, Glomma and Skien) accounting for nearly a quarter of the stations. This trend was followed by stations in northern Norway, northern and eastern Sweden, and Finland. Another high density of stations can be found along England (UK) and in the Danube river basin passing through Serbia, Slovakia, Romania, Slovenia, Austria, Bulgaria, Ukraine, Croatia, and Germany. To a minor extent, stations also exceeding the 90% quantile are scattered in northern Spain (Ebro, Douro and Minho basins) and southern Spain (Guadalquivir, Guadalhorce, Guadiaro and Velez). A lower density can be found in the Dnieper and Dniester basins (Ukraine) and Rhone basin (one station in Switzerland and another in France). Isolated stations exceeding the 90% quantile can be seen in the Oder (Poland), Rhine (Germany), Po (Italy) and Vistula (Slovakia) basins.

Finally, and according to stations registering values below the 10% quantile, these are mainly located in central Norway, Ukraine (Dnieper basin) and in Germany across the Rhine, Danube and Elbe basins with a remarkable concentration of stations. A lower density of stations can be found in the Oder basin (Poland), and isolated stations also showing values below the 10% quantile are located in the Avon river (England) and the Tangvattnet river (Sweden, close to the Norwegian border).