Extensometer-based monitoring of active deformation at the Khoko landslide (Jivari, Georgia)

There are several ways to monitor the evolution of a mass movement in mountainous areas, such as a landslide: from inclinometers, helpful in measuring deep deformation, to piezometers, for determining water level within the unstable mass, to electronic and manual extensometers, suitable for assessing local deformation. Here, we document the results of an extensometer-based campaign of measurements carried out in Georgia from 2016 to 2019, at the giant Khoko landslide, located on the southern slope of the Greater Caucasus. The campaign was conducted in the framework of a NATO-funded project, aimed at identifying geohazards affecting the Enguri artificial reservoir and the related hydroelectrical plant. Our results, which are meant to be integrated by the more accurate GPS-measurements performed during the NATO-supported project, indicate that the Khoko landslide is indeed active, and its displacements appear to be controlled by variations in hydraulic load, in turn induced by lake oscillations and, although to a minor extent, by rainfall.