|
Cycle 4 (2015 Deadline)
Landslide risk index mapping for Lebanon
PI: Grace Abou-Jaoude (grace.aboujaoude@lau.edu.lb), Lebanese American University
U.S. Partner: Joseph Wartman, University of Washington
Project Dates: October 2015 - March 2017
Project Overview
Landslides threats have traditionally been considered in the context of hazard (the likelihood or annual frequency of occurrence) rather than risk, which is a function of both hazard and the resulting consequences. This project will develop risk-based landslide maps, thus advancing the state of the practice in regional-scale landslide assessment. Products from the U.S. Government-supported partner’s current work on landslide vulnerability will applied in this internaitonal collaborative effort. Specifically, the research team will quantify the effects of landslide damages on residential and commercial structures based on the outcomes of the U.S. partner’s research. These are expected to include the fragility relationships relating landslide characteristics to building, community, and infrastructure damage, as well as risks to life-safety. Modifications will be made to these vulnerability characteristics as appropriate for building styles and construction practices in Lebanon. This research will drive the shift from currently employed qualitative assessment procedures to modern risk-based methodologies. The assessment techniques of the US project consider the combinations of landslide failure mode, topography, and building type that result in loss-of-life and capital losses. As part of this new collaborative PEER project, these techniques will be applied for the first time over regional scales in Lebanon using spatial databases of geology, topography, and building styles.
Conducted by the same Lebanese-U.S. team, PEER Project 1-163 (June 2012-May 2015) focused on generating a co-seismic landslide hazard map of Lebanon. The team developed the understanding that hazard mapping alone is not sufficient. Landslide-risk assessment will provide public officials, policy-makers, and geotechnical engineers meaningful information for directly estimating human and capital losses. The landslide risk maps will serve USAID’s work on Urban Programs by helping cities to identify areas with high natural risk potential and develop proper urban growth planning. This will also link to the unplanned temporary camps that are rapidly expanding in Lebanon in response to the crisis in Syria. As “temporary” camps, the settlements are unplanned, so traditional land-use measures have not been employed. However, experience in Lebanon has repeatedly shown that such “temporary” camps usually become permanent settlements. The explicit life-safety risks posed to residents of the settlements (as well as other long-established part of the country) are unknown. In this new project, the impact of precipitation- and earthquake-induced landslide events on people and structures will be evaluated. At the end of the project, the developed maps will be disseminated to urban planners, policy-makers, geotechnical engineers, non-governmental organizations, and the Disaster and Risk Management Unit in Lebanon. The maps will highlight the zones that are prone to the highest risks of danger and will prompt officials to take the necessary mitigation actions. The project’s broader impact will be to prevent damage and save lives due to landslide disasters by providing a basis for properly managing urban growth away from the identified critical zones. This should ultimately help in preserving the country’s economy when facing such devastating natural hazards.
Final Summary of Project Activities
Building upon a previous PEER grant, the research team developed comprehensive landslide risk index maps in Lebanon to identify areas with high risks of human loss and infrastructure damage associated with rainfall and earthquake-induced landslides. The landslide risk index was based on a multi-modal approach, decided in collaboration with a U.S. based team, to assess landslide impacts on structures and identify elements at risk. The project was important on a national scale to reduce and mitigate disaster risks. The results can ultimately be used to properly manage urban growth away from the identified critical zones.
After an extensive literature review, the two teams settled on research methodologies to assess hazards from rock falls, debris flows, and sliding. Hazard maps identifying falling rock and debris flow hazards were generated by the team at Lebanon American University, specifically research assistant Miriam Tawk. The team evaluated risk by identifying elements exposed in susceptible areas, including demographic and socioeconomic factors. The research team also identified three main types of areas at risk: the road network, urbanized areas within villages, and informal settlements. The main occupants of the informal settlements are Syrian refugees, and field visits by the PEER team clearly showed these settlements are at very high risk in the event of any natural disaster.
The Lebanese and U.S. research teams met twice across the grant period, including when the University of Washington team came to Lebanon. During the UW team’s visit, they participated in a second PEER project workshop and joined “ground-truthing” visits in two areas where the PEER project predicted high hazards and risks. The field visits confirmed many of the predicted locations.
The PEER project team dissemination workshop was well attended by government officials, faculty, students, and practitioners. Among the participants were representatives from the National Disaster Risk Reduction and Management Unit, the Order of Engineers and Architects, the National Research Council, the Civil Defense, and the Council for Development and Reconstruction.
The researchers also collaborated with the RUMMARE team, part of the National Research Council, to conduct work related to mass movement hazards and risks in Lebanon. The sub-committee on landslide hazards at the Lebanese Parliament has expressed interest in the results of the work. A representative from the Disaster and Risk Management Unit in Lebanon showed high interest in the developed maps to help them identify the villages that are prone to the highest landslide risks and take the necessary mitigation actions.
Publications
A. Grant, J. Wartman, G. Abou-Jaoude. 2016. Multi-Modal Method for Coseismic Landslide Hazard Assessment. Engineering Geology 212: 146-160. https://doi.org/10.1016/j.enggeo.2016.08.005
A. Saade, G. Abou-Jaoude, and J. Wartman. 2016. Regional-scale co-seismic landslide assessment using limit equilibrium analysis. Engineering Geology 204: 53-64. https://doi.org/10.1016/j.enggeo.2016.02.004
Back to PEER Cycle 4 Grant Recipients
|
