LAUSR

The natural hazard assessment is hampered by many difficulties due to the complexity of the phenomenon and the need to manage simultaneously several natural and/or technological hazards. Such is the case of most unstable urban sites in Algeria. The paper presents a risk analysis study of landslides and their reactivation in Tigzirt coastal city, located in the north of Algeria, which is classified in a moderate seismic zone. The spatial techniques based on geographic information systems are used to assess landslide susceptibility and hazard. Two qualitative studies of landslide hazard assessment are conducted using parameters defining the Algerian landslides context. The hazard is evaluated by performing a combination of the landslide susceptibility and the urban density. Earthquake-induced landslide hazard is assessed taking into account the Algerian seismicity. The study led to determination and mapping of the hazard induced by Tigzirt landslides.