Microzonation of landslide hazard triggered by earthquakes - Application of GIS methodology

The numerous historic data and results from investigations on the earthquake effects during the last decades show that site conditions play the major role in establishing the earthquake damage potential. Landslides and liquefaction, as direct seismic effects, are causing some pattern of soil failure, often found as the most destructive one. In fact, damage from triggered landslides has sometimes exceeded damage directly related to strong shaking and fault rupture [Jibson et al., 2000]. The subject of this research study is analysis and zoning of the geographical distribution of landslide hazards, as one of the most characteristic forms of geotechnical instabilities occurring during earthquakes, by application of the GIS methodology. For this purpose, a detailed GIS procedure for analysis and zoning of the landslide potential in earthquake conditions has been carried out, for the selected area. The analyzed area is a selected urban part of Skopje, capital city of Macedonia. All the documentation on the selected area necessary for analysis of the landslide hazard have been digitized, georeferenced and analyzed by Arcview 9.3, GIS software. The final product is represented by digital maps of expected permanent displacements for a defined earthquake scenario, in different water-saturation conditions of the instable soil layer. Results from this study, such as the potentially affected population and infrastructure, can be used as a data base for preventive mitigation activities for reducing the seismic risk in urban areas.