Status: 12.10.2022 8:25 AM
Heavy rain, floods and flash floods – due to climate change, extreme weather events will become more frequent in the future. With flood protection, an app should now help identify unknown danger zones in advance.
By Frank Grotelüschen, Deutschlandfunk
July 2021, the flood disaster in the Ahr Valley: more than 130 people are killed and about 500 buildings are destroyed. The consequences are also so disastrous because some houses, roads and bridges are built in an unfavorable way: in heavy rain they hinder the rapid drainage of the water masses, and a flood turns into a flash flood. Even small causes can have major consequences, such as a barrier in a stream. According to Katharina Haupenthal of the University of Applied Sciences Trier, quicksand, which washes ashore during heavy rain, then gets stuck in front of this grid. This causes the water to rise and flow into the gardens.
Robot to find waterfalls
There are many such obstacles where water accumulates and cannot flow away. But not all of them are known and mapped – and therefore cannot be systematically eliminated. Therefore, a research team from Trier and Koblenz is now working on techniques to more accurately identify such obstacles. A small rover uses a laser scanner to search for potential waterfalls in risk areas.
According to Haupenthal, the idea is that he can drive through the streets and recognize bumps in sidewalks, in streets, in small construction conditions. For example, you could see where there are problems, where the water is drained into the basement of a house? And where should the community change?
Residents can report dangerous places
A second technique requires the cooperation of local residents: they often know best where the water collects in their neighborhood when it pours heavily. The idea: People should use a smartphone app to report to authorities if they discover a critical spot. A first version is already ready, says Haupenthal, pointing to her smartphone. “The app can record my location. And via an input mask there is the possibility to select the type of problem, for example ‘clogging by deposits’.” Users can also enter a short problem report, photograph the obstacle and then send it to the operator.
Sounds pretty simple – but there are some pitfalls. According to Haupenthal, how do you know that that information is correct? When people enter data for fun, to try, it skews the results.
Plausibility check for data
To prevent this, the experts themselves want to check the quality of the data for plausibility, which should be enough to unmask possible pranksters. Later this could be done automatically by software. The project will run until early 2025, when Haupenthal and her colleagues want to present a ready-to-use app. The idea is actually to be able to provide the municipalities with a kind of toolbox. Tools that allow them to display their hazard maps in a higher resolution.
One of the partner municipalities is the municipality of Altenahr. It is true that she currently has more pressing problems than developing a smartphone app. In the long run, however, the new technology can certainly ensure that extreme rainfall does not have as catastrophic consequences as it did in the summer of 2021.
Flash flooding app: Citizen Science must improve flood protection
Frank Grotelüschen, Deutschlandfunk, October 12, 2022 10:02 am