Large landslide risk assessment in hilly areas. a case study of huşi town region (north-east of romania)

Abstract

Large landslides are a common geomorphological characteristic of the Moldavian Plateau (Romania), their presence and manifestation being favored mainly by geological and climatic conditions. In numerous cases, the spatial pattern of the large landslides is under the form of amphitheatres, with impressive dimensions, reaching sizes of hundreds of hectares. Due to their defensive characteristics, these landforms often constituted sites for settlements location during the Middle Ages. The constant growing of the human pressure (19th, 20th century) had led to the settlements extension in areas of high slope instability. A representative case of settlements location on these landforms is the Huşi town, with a population of 25.000 inhabitants, situated in the central part of the Moldavian Plateau. The landslide risk assessment for the Huşi town area (approximately 79 km2) was performed on the basis of landslide susceptibility and exposed elements maps. Landslide susceptibility was assessed using the logistic regression approach, taking into account ten quantitative and qualitative factors. The cartographic base was represented by topographic maps at scale 1:5.000 and the high resolution orthorectified aerial image (2010). The elements exposed to risk were digitized from the same primary cartographic materials and the General Urban Plan provided by local administration. The results indicate high level of landslide susceptibility on the southern side of the Huşi town and this should be seriously considered by the decision makers in the land planning projects.