Hazard and Risk Related to Earthquake-Triggered Landslides

This paper first analyses how important earthquake-induced landslide hazards are compared to other geohazards at world-wide scale. Further, we will outline where these hazards may have the strongest impacts-at regional and local scale. In this regard, we consider the short-and long-term effects of geological, tectonic, climatic and morphological conditions. Hazard and risk related to these processes will also be analysed on the basis of a series of case histories: e.g., the 1920 Haiyuan earthquake-landslide disaster in China. A detailed report will be provided for two events in Central Asia: the earthquakes of Khait in 1949 and Suusamyr in 1992. Focus will also be on the risk related to mega-events such as the Usoy rockslide dam in Tajikistan and giant rockslides in other parts of Central Asia and in the world. One conclusion is that in semi-arid mountain regions marked by a strong seismic activity, such as those in Central Asia and North-western China, seismogenic landslides and related long-term effects may represent the most important geohazards. Further, the susceptibility to seismic slope instability is highest along active fault zones and on convex slopes made of soft or fractured materials.