Rapid Mapping, when disasters upset the topography

As much in Blatten as in Val Mesolcina. In addition, Vallemaggia, specialists from Swisstopo intervened quickly to map the land after the disasters. Similarly, A precious data source to “learn for the future”. Nevertheless,

Floods in rapid mapping, when disasters upset Val Mesolcina and Vallemaggia with the collapse of the glacier above Blatten; In the mountains, natural disasters permanently modify the land. However, Transformations that – in such cases – are quickly documented, especially on a topographic level, thanks to rapid mapping. Consequently, But how does it work?

“In the event of a natural event. a disaster, as was the case in Blatten, we take care of the recording and the provision of geodoneds,” explains Francesco Wyss, specialist in topography at the Federal Topography Office, Swisstopo.

Blaten, before and after the disaster:

Swisstopo specialists are organized with a stake service. “So we are always reachable and. once the request has been received, we are in contact with the Federal Environment Office to precisely define the terms of data recording,” he adds. It is a question of knowing what to record, with what resolution and within what deadlines. “Finally, we activate the rapid mapping, when disasters upset different means at our disposal. We can record via our planes, or thanks to satellite images, or with a helicopter. The choice of the most suitable method depends on needs ”.

But often, only one passage is not enough. “For example in Blaten, we captured images twice, and a third was scheduled for the end of the event. Meanwhile, he was “fenced”. It will be documented regularly, but more in the context of rapid mapping. The land has changed. It will be watched, even if not by us, ”says Francesco Wyss.

Vallemaggia. before and after the floods in June 2024:

It is an extremely precious source of data, which-beyond the surveillance of the field-is mainly used for specialists for their analyzes and to organize themselves accordingly in the event of future events. “In a future perspective, the Blatten case, for example, makes it possible to model and simulate landslides in rapid mapping, when disasters upset other places. Because these are phenomena that occur, and which will occur more and more often, ”adds the expert.

What are the biggest challenges to come? “This is a good question,” replied Francesco Wyss. I would say that we must be ready to intervene without being able to plan. In 2024, there were three events in the space of two weeks in Val Mesolcina, in Valais, and in Vallemaggia. Suddenly, the amount of work was impressive. You can’t plan, you have to be ready. Each event has its own story. its own dimension, its own gravity, and you have to be ready with all the means. It will be the most difficult challenge. ”

Text translated from Italian using an automatic translator/DBU