Tectonic and structural control of landslide hazards in the Outer Carpathian Mountains, Ukraine

Abstract Landslide processes in the Carpathian Mountains represent a major hazard threatening both human lives and the socio-economic development and infrastructure of the region. The Carpathians are vulnerable to landslide hazards due to several factors related to regional geology and tectonics. The main goal of this study is to examine the main factors influencing landslides in the Outer Carpathian Mountains in Ukraine, to understand which factor(s) have the most impact on landslide susceptibility, and finally to demonstrate the potential of the integrated technique for assessment of landslide hazards at the regional and local scale. This analysis confirms the essential role of tectonics in landslide formation. Genetic classification and formation mechanisms of landslides are spatially associated with fracture zones. Fracture zones are generally subparallel to river valleys but locally are orthogonal or diagonal. This article examines the conditions of landslide formation associated with fracture zones orthogonal to river valleys. Landslide occurrence and the corresponding damage to infrastructure within such zones exhibit a localized character dictated by the width of fracture zones. These zones are clearly expressed in the topography. Therefore, in the regional classification of landslides in the Outer Carpathians it is necessary to add the landslides associated with a tectonic structure of various nature and orientations. This study also provides valuable insights for hazard preparedness and landslide risk reduction in the region.