Flood 2024. From polders to resettlements. Hydrologist on how to prepare for a “catastrophe”

Head of the Department of Hydrology and Climatology at Maria Curie-Skłodowska University in Lublin Lublin Dr. Hab. Stanisław Chmiel, professor at UMCS, pointed out that in every disaster there are always voices saying that it would have been possible to prepare better for the flood and mitigate its effects. According to him, this is not only a problem for Poland, because in other countries, such as the Czech Republic, Slovakia, Germany or Austria, extreme weather phenomena also occur.

– Disasters are unpredictable. Of course, we could have prepared better for this flood, but it is not a matter of one or two months, but of many years. Discussions on the method of flood protection were held, but not always adequate decisions were made. The initiative to build a reservoir in Racibórz was certainly a good one, thanks to which there is a greater chance of protecting Kędzierzyn, OpoleWhether Wroclaw – said the hydrologist.

In his opinion, the current situation has shown that we still have too few retention reservoirs in Poland, mainly in areas where flash floods occur. He pointed to the need to build especially dry flood reservoirs, i.e. polders, in mountain and foothill areas, which will capture excess water.

– However, this does not guarantee complete protection. I doubt that it is even possible to build so many reservoirs that there will be no flood threats. After all, disasters do happen that simply cannot be stopped – noted Dr. Hab. Stanisław Chmiel.

He stressed that in this case the flood was primarily caused by the catastrophic intensity of rainfall, and an additional impact was caused by the insufficient number of retention reservoirs, drought, deforestation and, especially, development near rivers.

Asked what else needs to be done, the UMCS professor indicated that the priority should be to limit development in flood areas in order to mitigate the effects of possible floods.

– While floodplain maps have been created for major rivers in recent years, they are still lacking for smaller rivers, their tributaries, seasonal streams, and even dry valleys that occasionally receive surface runoff. This is where we are dealing with the issuance of new building permits. As the current situation has shown, it is precisely small streams that have become large, rushing rivers, and this has contributed to so many disasters – explained the expert.

>>> CHECK ALSO: River levels in Poland. Where are the alarm levels exceeded. Map

In his opinion, a discussion should also be started on the proposal of resettlement for people living in flood areas. He assessed that the best time for this is the period immediately after the flood, then people are most willing to make such decisions.

– We must be aware that these are very difficult decisions for people living in such areas – admitted Prof. Chmiel.

Asked about the misconception that flooding is not a threat during droughts, he explained that if the soil is dry and there is heavy rain, at some point the soil becomes practically impermeable, as if it were frozen or covered with asphalt. – A cushion is created that causes the water not to soak in, but to flow rapidly over the surface – we say that it flows like a carpet – described the hydrologist.

Referring to the forecasts for the future, he explained that according to the observed trends, the frequency of weather anomalies is increasing in our area. This is related to the observed change in the circulation of air masses. – Warm air masses from the south flow into Poland more often, and if they collide with colder air from the north, we can expect heavy rainfall, despite the fact that we have a drought – noted Prof. Chmiel.

Flooding has been ongoing in southern and western Poland since Friday. The most difficult situation is in Lower Silesia and the Opole region. On Monday, the government declared a state of natural disaster in the areas affected by flooding.

>>> READ ALSO: Floods in Central Europe. 24 people died