Climate change has a considerably fortified heavy rain

The hydrologist Günter Blöschl explains that rainfall now has 15 percent more water. The reason is higher temperatures.

There is not every day that there is a study with data that comes entirely from Austria, evaluated by researchers from Technical University (TU) Vienna, the Geosphere Austria, the Ministry of Agriculture and the University of Graz. However, it is about findings that are valid for large parts of the earth and above all explained for the medium -sized wide validity Blöschl. Here you show how the increased temperatures influence the regional level, and what that means for the flood situation.

Two rows of measurements of more than 100 years
Since the precipitation of two independent positions in Austria is carefully documented in parallel -for the first by the GeoSphere Austria, the former Central Institute for Meteorology and Geodynamics (ZAMG), and secondly the hydrographic service -this can be investigated in detail. There are a total of 883 rural measuring stations, of which 163 also increase values ​​every hour. The scientists were able to analyze precise series of measurements from 1900 to 2023 accordingly, there was no second time, according to the hydrologist.

How the average temperatures increase as a result of climate change – in Austria the plus is currently around two degrees Celsius – have an influence on heavy rain events, especially in the summer months, is one of the big questions in climate research and for flooding management. Behind it is the realization that air can absorb seven percent more water vapor per extra degree Celsius. There are also questions about how the extra energy in the regional system influences. The stronger warming in the area of ​​the soil also means that the warm air masses have risen faster from there. So you will be cooled up faster, which leads to more rain, Blöschl explains.

Average heavy rainfall today much more productive
It was believed that the precipitation events had to increase in the short term. According to the hydrologist you could now moor at this level. In Austria, the data even offer an evaluation of the rainy quantities per hour from 1950. In fact there was no significant change here from 1950 to 1980. Then it went up for more than 40 years: “In the period 2003 to 2023, an average heavy rain brought 15 percent more water than an average heavy rainfall in the period 1950 to 1970,” said first author from targeter Haslinger.

This development is less related to the large global circulation in the atmosphere, but usually explains the extra energy that is available locally: “This also means that this is more or less everywhere outside the tropics. That is the first study worldwide that shows that.

Smaller plus with extreme daily quantities
The fact that heavy rainfall in particular is more violent in the short term is that the rainy quantity has increased by only eight percent within a whole day during extreme events from the nineties to the years 2010. So if precipitation events increase more than long -term intensive rain phases in the short term, this also means that different regions are differently influenced by flooding.

According to the research results, falling floods caused by violent, one or two hours of thunderstorms and floods in smaller river shops will be even more expected in the future. The fact that this is the case is already clear in the domestic flood data. “But there is no flood in the Danube,” said Blöschl.

What happens regionally for floods in the fall?
This means that one has to think more about regional flood protection in smaller areas and analyze exactly how even more intensive, short heavy rainfall events in a specific region have an impact. Because: with global warming, according to the hydrologist the short heavy series on average in Germany in Germany.