Ischia, the satellite disaster and landslide risk maps

A few hours after the landslide in the municipality of Casamicciola Terme, on the island of Ischia, on the night between 25 and 26 November, the Copernicus emergency management service was activated, the European Union service with ESA satellites which, thanks to overflights from space, is able to give first glimpse of what happened. In the first published observations, the path of the landslide on the slope of Mount Epomeo was identified.

The area highlighted by the satellite data is located in one of the zones that the landslide risk maps of the Campania Region indicate as R4, i.e. the highest level (in red). While such close contour lines (the lines indicating slope) on the map mean that point is among the steepest.

The record rainfall, 126 millimeters of rain in six hours, never happened in the last 20 years, has saturated the ground, triggering what geologists are calling a flash flood of debris. The river of mud has overwhelmed everything it encountered during the steep descent, at least one other wall has crumbled, at the foot of a building whose windows now overlook the void, identified by Copernicus technicians on the map. According to the maps of the Region, a large part of the island of Ischia (and of the municipality of Casamicciola Terme) is at high risk of landslides, as well as a good part of the territory and the Italian population (at least one million and 400 thousand people live in areas high or very high risk).

Atmospheric events made increasingly violent by global warming can only aggravate the emergency, especially in those areas where a high land consumption has been added to the risk of instability or flooding, as Ispra pointed out in a tweet, taking the island of Ischia as an example.