All forecasts are coming true, the Genoese low will bring “very extensive, intense and wide zones of rainfall” – said tvnmeteo.pl presenter and weather forecaster Tomasz Wasilewski in the program “Tak jest” on TVN24. Prof. Artur Magnuszewski from the University of Warsaw talked about the similarities and differences between the current situation and that of 1997 and whether we have learned our lesson after the flood of the millennium.
Southern Poland is preparing for heavy rainfall, flooding and overflows. This is due to the influence of the Genoese low Boris.
Professor Artur Magnuszewski, hydrologist from the Department of Hydrology at the University of Warsaw, and Tomasz Wasilewski, presenter and weather forecaster at tvnmeteo.pl, talked about the disturbing forecasts for the coming days in the “Tak jest” programme.
As Wasilewski pointed out, all forecasts are coming true – the Genoese low “will be over the south-eastern part of the country tonight” and will bring “very extensive, intense and wide zones of precipitation” over central Europe. According to the tvnmeteo.pl expert, the situation is particularly difficult in the Czech Republic, where “half of the country's surface has forecasted precipitation of around 200-300 liters of water per square meter.”
Meteorological warningstvnmeteo.pl for IMWM
Small rivers become “monstrous, rushing streams”
Tomasz Wasilewski pointed out, recalling Głuchołazy, which was flooded in 1997, that the “main danger” may turn out to be smaller rivers. – Every day, you cross them on a small footbridge. These small rivers turn into such monstrous, rushing, large, spreading streams. It happens very quickly – said Wasilewski.
He noted that in Głuchołazy “about 80 liters of water per square meter have fallen since Thursday, and about 90 liters will fall overnight and on Saturday, and about 100 liters on Sunday.” – This rainfall will be greater than what has occurred, but it will also encounter water that has already fallen there. Day after day and hour after hour, this total rainfall will accumulate, so there will be more and more water – he said. He noted that “mountain rivers” may react the fastest and most violently.
Wasilewski: small rivers turn into rushing streamsTVN24
Are we in for a repeat of the flood of the millennium?
In the public space, the threat in Lower Silesia is compared to the flood of 1997, called the flood of the millennium. Prof. Magnuszewski spoke about whether such a comparison is justified in this case.
– The similarity occurs at the level of the meteorological situation. If we were to reach for studies concerning the flood in 1997, we would see a very similar air circulation system. The low, which also formed over northern Italy in 1997, led to moist air from the Caspian Sea and the Mediterranean Sea entering Poland – explained the hydrologist.
He also said that the air mass that reaches our country from the south “is a huge carrier of water”.
Professor Magnuszewski was also asked about how he assessed the capacity of rivers and other reservoirs to absorb such a large amount of water in comparison to the flood of 1997. – Before the flood in 1997, there was considerable rainfall in the Sudetes region, so the starting point was different. Now we have had a long period of drought and this is such good news when it comes to this starting point – said the guest of “Tak jest”.
– The second issue is precisely the flood retention, which is created in reservoirs in Poland. In 1997, the retention reservoirs were approximately half emptied. This flood reserve was not one hundred percent available, they were partially filled with water – he said and specified that today the reservoirs are emptied, which will allow for “greater freedom in controlling this flood”.
Another piece of reassuring news is that “the middle Oder currently has an average water level, while the entire lower Oder below the mouth of the Warta is in low water level zones”. – This is good news because, in addition to the capacity we have in artificial reservoirs, such riverbed retention is also important, i.e. in the riverbeds and valley. In the case of the Oder, this retention is maintained – said the professor.
Heavy rains are expected to hit much of Poland over the weekend. Preparations are underwayJacek Tacik/Fakty TVN
Hydrologist: We have learned our lesson from the floods in 1997 and 2010
Magnuszewski also pointed out that information capabilities are much better than 27 years ago. – After the flood in 1997, a network of weather radars was created in Poland. This is also an effect of that flood. Of course, it brought great losses, but the positive side of this phenomenon is that we have learned our lesson – said the professor.
He added that after the flood of the millennium, a lot of investments were made in the field of technical infrastructure. – Many dry reservoirs have been prepared. In Wroclaw the hydraulic capacity of the entire city system has been improved. In turn, the lesson from the 2010 flood that we have learned is primarily digital terrain models. At that time, we did not know exactly which way the water would flow. (…) Today we have excellent information on the terrain in the river valleys, but also in flood areas. We have flood risk management maps. This is also something very much needed in crisis management conditions – he said.
Main image source: PAP/Tomasz Wojtasik