Mihai Ciprian Mărgărint

Landslide Susceptibility Assessment: GIS Application to a Complex Mountainous Environment

This study attempts to quantify landslide susceptibility in the upper Putna River basin in the Romanian Carpathians Bend using GIS techniques and logistic regression. First, a detailed landslide inventory was carried out and a GIS database was built, comprising potential predictors of landslide occurrence. The GIS database included 11 quantitative predictors, mostly geomorphometric parameters, and 4 qualitative predictors which were transformed into quantitative variables using landslide density approach. The logistic regression analysis, combined with a stepwise selection of the predictors, showed that landslide occurrence is best explained by slope inclination class, altitude, soil class, distance to drainage network and surface geology. The results show that the potentially unstable terrains, displaying high and very high landslide susceptibility values, cover an area about 3 times greater than the mapped landslide area.

Landslide Type and Pattern in Moldavian Plateau, NE Romania

This study proposes a regional scale approach of landslide typology and patterns for the Moldavian Plateau, one of the Romanian regions most affected by mass movement processes. A regional historical landslide inventory was carried out, using remote sensing imagery, resulting a number of 24,263 polygons, which cover 18.3 % of the whole study area (24,803 km2). Preconditioning, preparatory, and triggering factors were revised and the following types of landslides were identified and attributed in the inventory: rotational, translational, lateral spread, flows, and complex landslides. The statistic interpretations of the geomorphometric variables of the polygons that define the areas affected by landslides, reveal a strong relation between the landslide phenomenon and the lithology, the morphostructure and the topography. The general pattern of landslide distribution emphasizes a repetitive model along cuesta scarp slopes; this is mainly related to the lithology dominated by limestones, sandstones, and volcanic consolidated tuffs at the upper part of the slopes, with friable clayey and sandy strata intercalations. The landslide inventory and the revealed types and patterns of landslides are an essential step for a better understanding of landslide phenomenon, landslide risk assessment, and landslide management in the Moldavian Plateau.