landslide

Hilly regions around the world are one of the most vulnerable places for inhabitation, where landslides represent a permanent threat for their population. In some particular cases, in the past, due to their topographic features, areas affected by massive landslides served a real opportunity for the location of strategic and fortified settlements.

Natural hazards are the most significant threats in rural areas of Romania, while landslides, floods and bank river erosion are the geomorphological processes that impose the greatest risk in the Moldavian Plateau. We have identified 189 of disappeared, displaced and partially affected villages (in the area between Siret and Prut Rivers), using old cartographic materials as primary tool, and overlapping them with the present situation: ortophoto imagery and LiDAR derived high-resolution Digital Elevation Models (DEMs).

Today, as in the past, people living in hilly and mountainous regions have had to face the consequences of mass movement processes. Archaeological remains are important elements of cultural heritage, which can be significantly affected by landslides in different environmental settings and landscape evolution phases. In the Eastern Carpathians lowlands, landslides have shaped a landscape with inaccessible escarpments tens of metres high, providing ancient populations with naturally defensive sites at which to build their fortified settlements.

The creation and analysis of landslide inventories is the basic approach for starting the landslide hazard to risk analysis chain analysis. In order to perform this kind of analysis for the Iași Municipality (North–eastern Romania) we created based on aerial imagery and LiDAR data a landslide inventory of the landslide events that happened in the last 100 years. In total, we identified and delineated 518 landslide events: 51.5% translational slides, 19.7% slumps (rotational slides), 17% flowslides and 11.8% flows.

Iași Municipality as other urban areas around the world has a long history of landslide activity which needs to be studied considering the urban sprawl. We performed a first landslide susceptibility modeling for Iași Municipality based on the AHP method using weights given by expert judgements regarding the influence of preparatory and conditional landslides factors (slope, ruggedness, lithology, historic landslide density and hydrogeology) and weights given by the historic landslide density over the factors.