Evolutionary behaviour of the Tessina landslide

The Tessina Landslide is a complex landslide active since more than 50 years in the Alpago area (Belluno, Italy). The evolution of the landslide is typical of Tertiary Flysch formations, characterized by some medium-large roto-traslational slides, periodically occurring in the source area, and then turning into mudflows, leading to risky conditions for the lower valley. In the last decades, it has been intensively studied and monitored with the aim of better understanding its evolution mechanisms and adopting a mitigation strategy for risk reduction. The paper presents data recorded by two different real-time monitoring systems, recently installed in the area. The first system measures the groundwater pressure and the displacements of a lateral sector playing a crucial role for the stability of the whole area; the second one is a new photographic-based system, which takes continuously along with time digital images of the upper scarps with the aim of evaluating the trigger mechanisms of mudflows in the depletion basin. The experimental information collected so far permit to understand the stability evolution of the various landslide portions together with the mudflow formation process, necessary to evaluate the effectiveness of possible future mitigation works.