Epistemic uncertainties induced by landslides typology in Vrancea seismic region (SE Carpathians, Romania) and their implication in hazard evaluation

Vrancea seismic region, corresponding to the Curvature sector of the SE (Romanian) Carpathians, represents a very active geomorphic region, marked by a wide variety of fluvial, slope gravitational and seismic processes. The morpho-litho-structural traits, the active neotectonic movements, the climatic regime and the human influence are controlling a complex multi-hazard environment. Accordingly, numerous landslide hazard evaluation attempts have been developed during the last decade, and several landslide inventories were used to calibrate and validate statistic and probabilistic susceptibility models. However, comparing various results, it was seen that fine-tuned regional susceptibility models, performing properly from a statistical point of view, resulted in differently-distributed susceptibility classes, potentially inducing confusions among stakeholders and end-users. It is the purpose of this presentation to outline the geomorphic complexity of landslides typology in the study-area, and the induced epistemic uncertainties. Different landslide inventories (based on field mapping, optical remote sensing imagery, radar interpherometry) and bi/multivariate statistical approaches are being discussed, and slope sensitivity, geomorphic complexity of landslides, their evolution, frequency-magnitude relationship, triggering thresholds, morphodynamic sectors and connectivity are evaluated as potential sources of epistemic uncertainties. The presentation concludes with a series of recommendations meant to support the development of more robust and highly predictive susceptibility models and hazard evaluation. By enriching such methodology for evaluating the past, present and future behavior of such processes, the geomorphologists may foster numerous stakeholders to develop the optimal proactive measures for risk prevention and preparedness and the most suitable reactive actions for response and recovery.

Key words: Vrancea seismic region, Romania, Carpathians, landslides typology, epistemic uncertainty