Complex Back Analysis of Historical Landslide Events from Iasi Municipality, Romania

Abstract:

Iasi Municipality (Romania) is a regional hot-spot of urban landslides, more than 75% of its territory being included in a landslide hazard zone. Historically, the urban landslide activity started after the Medieval Period, when the city extended from the 20 m Bahlui river fluvial terrace toward the adjacent Bahlui Valley hillslopes. The historical landslides are events that reactivated Holocene old and dormant landslide bodies and scarps. Historical sources and scientific papers were used for the identification of the landslide events and their characteristics, both in terms of hazard (magnitude), vulnerability, and risk (losses). Further, fieldwork, topographic maps, and high-resolution LiDAR data were used to map the landslide probable extension and topography. Finally, numerical modeling of the reconstructed topography was used to assess the mechanism and the probable factors. The obtained results regarding the associated hazard, vulnerability, and risk, should be used for the reevaluation of the hazard and risk zonation, considering the new technological and climate realities from the present-day and the near-future.