Original paper

Landslide susceptibility zoning in the Polish Flysch Carpathians

Dlugosz, Michal


In the Flysch Carpatians landslides play a crucial role in relief shaping and alteration of surface features. Landslides in this region are among the most hazardous natural phenomena and may trigger significant environmental and socio-economical losses. The objective of the present paper is to provide a landslide susceptibility map of the Polish Carpathians Mountain to illustrate the most hazardous regions in the study area and show the spatial distribution of the most landslide-prone areas. Many techniques have been suggested for landslide hazard zonation. This study employed direct hazard mapping, in which the degree of hazard is determined by a geomorphologists, based on literature and analysis of terrain conditions (Zabuski et al. 1999). This study was based on the slope gradient map generated from the digital elevation model and on the geological map that was made by digitalizing the Polish Carpathians Geology Map with a scale of 1:200 000. All GIS analysis was made using the Integrated Land and Water Information System ILWIS 3.4. A landslide hazard index was created for each category of each map. Both maps were combined into one landslide susceptibility map. The resulting map was validated statistically with the input landslide occurrence map for the chosen smaller area. The final map presents spatial distribution of the most hazardous regions in the Polish Flysch Carpathians. However, the resulted landslide susceptibility map provides only a general overview of the magnitude of mass movement for such large mountainous areas.