Roquebillière landslide | France
Images of the project
A proven geological risk
This landslide’s sad history makes it one of the most famous in France.
The village of Roquebillière is located north of Nice, about 50km inland. The village is built at an altitude of 585m on the left bank of the Vésubie. Above it lies the village of Belvédère at an altitude of 829m.
The slope’s geology cannot be determined precisely. It comprises a surface deposit 30m to 70m high and a substratum composed mainly of gypsum. Gypsum has the characteristic of dissolving quickly on contact with water.
The site has suffered two major disasters. In November 1926, a mudslide swept away a large part of the village, claiming numerous lives. In 1971, further slow movement was identified on the slope.
Establishment of automated monitoring
Sixense were appointed by the DDTM 06 (Departmental Directorate of Territory and the Sea) to set up automatic monitoring of the Roquebillière landslide.
The purpose of the instruments installed by Sixense was not only to observe changes to the long-term risk factors of a landslide on the Roquebillière-Belvédère slope, but also to manage the transitional period during implementation of an effective solution to protect against or prevent risk, by providing a minimum level of real-time information during the development of a potential landslide.
The instruments included piezometers, pore pressure cells, sensors to measure water conductivity and automatic inclinometers. These sensors are connected to acquisition units positioned at various points on the slope. Data is recorded daily and transferred automatically.