Cycle 1 (2011 Deadline)
Earthquake-generated landslide hazard in Lebanon
PI: Grace Abou-Jaoude, Lebanese American University
U.S. Partner: Joseph Wartman, University of Washington
Project Dates: May 2012 - May 2015
Lebanon is located in a relatively high seismic zone and has a rugged topography, making it vulnerable to hazards from earthquakes and landslides. Records about seismic events in the country go back to 303 AD and contain descriptions about such damages as houses and monuments destroyed and widespread fires, but they offer few if any details about collateral damages from landslide hazards associated with earthquakes. Although Lebanon has not experienced any major earthquake since 1956, the recent discovery of an active thrusting fault close to its coastline has significantly raised its risk of being hit by a high magnitude earthquake. Past studies on seismic hazards in Lebanon have focused on seismic zoning and its impact on structural engineering design. Although many researchers have assessed slope stability hazards in Lebanon based on various static conditions, no effort has been undertaken as yet to assess the impact of a seismic event on triggering landslide hazards in the country.
This project aims to produce a hazard map of Lebanon that clearly shows the critical areas prone to earthquake-induced landslides. This goal will be achieved through three major activities to be conducted over a period of two years. The first task will be mapping the landslide prone zones in the Geographic Information Systems (GIS) framework, followed by a detailed geological field survey. The second task will focus on numerical modeling of slopes, including seismic slope stability analyses in order to evaluate the failure potential of sloping terrains when subjected to different seismic loading events. The third task will be to produce an up-to-date earthquake-induced landslide hazard map, taking into consideration the effects of the active faults in the country, the general terrain parameters, and the seismic slope stability analyses. Ultimately the project should help Lebanese cities to identify areas with high natural hazard potential so they can plan urban growth appropriately, thus preventing damage to critical infrastructure and saving lives in the event natural disasters strike.
Summary of Recent Activities
During the third quarter of 2014, Dr. Abou-Jaoude and her team tested their newly developed model for predicting earthquake-induced landslides in Lebanon against a post-earthquake landslide database. As Lebanon does not have such a database, the team tested their model’s accuracy against earthquake-induced landslides in Northridge, California due to its well-documented history and database of landslides resulting from earthquakes. The LAU team evaluated the proposed regression equations model by comparing the displacement estimates with observed landslides from the 1994 Northridge earthquake database.
The coming months will see Dr. Abou-Jaoude and her team travel to Seattle, Washington to meet with her counterpart, Dr. Wartman and his team. The teams will compare the results from their different models and draw conclusions regarding their accuracy in predicting landslide risks. The LAU team will also compile the results of their modelling and prepare for a dissemination workshop scheduled for February 2015.