The “Tektonik” Landslide at Mailuu Suu, Kyrgyz Republic

Abstract

Around Mailuu Suu, Jalalabad Oblast, Kyrgyz Republic, about 230 landslides have been documented. The cause of this unusual proliferation of landslides is an unfavorable concurrence of factors such as stratigraphy and lithology, intensive tectonic deformation, ongoing tectonic uplift, the precipitation pattern and associated potent (erosional) discharge and a Loess cover of significant thickness. Some of the landslides form potential hazards to radioactive mining waste (waste dumps and tailing management facilities) of abandoned uranium mines of the Soviet period. The appropriately named “Tektonik” landslide is one of the biggest landslides in the Mailuu Suu area and was formed during an initially highly active phase between 1969 and 1984. Today much of the unstable material has already been displaced and accumulated at the base of the slope in two major lobes of about 3 and 1.2 million m³, respectively. About 1 million m³ of material is still in active displacement, albeit at a very slow speed. The failure mechanisms observable in the field are sliding, toppling, falling and earth flow. To assess any residual risk of the (partly stabilized) “Tektonik” landslide to the (mostly removed) tailings management facilities (TMF) a detailed field mapping and topographical survey, with subsequent 3D rock-fall and 2D landslide modeling were carried out. The investigations showed that the remaining risk of dislocation and dissipation of radioactive tailings by landslide activity is low, and as long term mitigation measure only regular site visits are recommended to visually monitor landslide behavior and TMF condition.