Multihazards Seismic Impact in Mountainous Areas
Estimation of the Multihazards Seismic Impact in Mountainous Areas
Tech Area / Field
- ENV-MRA/Modelling and Risk Assessment/Environment
- OBS-GEO/Geology/Other Basic Sciences
- OBS-NAT/Natural Resources and Earth Sciences/Other Basic Sciences
3 Approved without Funding
Institute of Geology, Earthquake Engineering and Seismology, Tajikistan, Dushanbe
- Institute of Seismology, NAS, Kyrgyzstan, Bishkek
- Lawrence Livermore National Laboratory / Center for Global Security Research, USA, CA, Livermore\nGeoForschungsZentrum Potsdam, Germany, Potsdam\nUniversity of Liege, Belgium, Angleur\nNORSAR, Norway, Kjeller
Project summaryThe Project aim.Within the framework of this project it is planned to develop an up-to-date technique for the estimation of earthquake impacts considering various induced multihazards in mountain areas. The study will be applied to the two neighboring countries – Tajikistan and Kyrgyzstan, which are the regions most exposed to seismic hazards in Central Asia, and where the mountains occupy about 90% of the territory. Such a technique would allow us to provide more accurate predictions for land-use planning, as well as more reliable safety emergency preparedness plans for the population. Very accurate methods and approaches will be developed and applied to a pilot area in the South Tien Shan along the Kyrgyz-Tajik border, which is exposed to both a high seismic activity and a high susceptibility to slope failure on one hand, and includes densely populated areas in the mountains on the other hand.
Current status. Seismic hazard assessment for Central Asia was conducted in the past at a small scale (1:1000000) and averaging of earthquake parameters resulted in the loss of regional particularities of seismic events. In Tajikistan, the current Map of General Seismic Zoning was made in 1978, and has never been "off the mark" with regard to the measured seismic effects within the territory of Tajikistan. The same facts are observed for the territory of Kyrgyzstan. However, other facts give rise to serious concern about the applicability of such a map: actually, this map provides predictions mainly aimed at ensuring safety of buildings and structures with respect to the impact of seismic ground shaking while our experience indicates that most losses of human lives and considerable material damages in the target regions are associated with effects of secondary earthquake consequences: landslides, rock slides, debris flows and soil liquefaction. Dramatic examples, when people lost their lives not directly due to the seismic shaking but rather as a result of landslides, rockslides or debris flows, are given by such earthquakes as Karatag in 1907 (M=7.4), Sarez in 1911 (M=7.7), Faizabad in 1930 (M=6.4) and in 1943 (M=6.7), Khait in 1949 (M=7.4), Hissar in 1989 (M=5.5) in Tajikistan, and 1911 (M8.2) Chilik-Kemin, 1992 (M=7.3) in Kyrgyzstan. The most recent event in May 12, 2008 Wenchuan earthquake in China (M=7.8) has damaged 1803 dams and reservoirs, and triggered tens of thousands of landslides over an area of many thousands of square kilometers.
The existing seismic hazard maps don’t take into account such consequences though above examples indicate the importance of such analysis.
The project’ influence on progress in this area. The Project methodology and technique of multihazards seismic impact estimation for mountainous areas are based on the up-to-date GIS data base compilation and analysis, modern seismic hazard and landslide hazard estimation technique that will be worked out during the Project implementation and allows us to provide more accurate assessment of real seismic impact for population and property.
The participants’ expertise.The scientists involved in this project have many years of considerable experience to work in seismic active mountainous areas and study not only seismicity, but other natural hazards especially landslide, rock falls and debris flows, including the earthquake triggered events. They take part in some international projects (CASRI, TIPAGE, GEM, TIPTIMON and other). Some information is available on the Internet web-site http://www.ingeos.tj and http://www.seismo.kg.
Expected results and their application. The final output of this project will be a new verified methodology and approach of multihazards analysis applicable to seismically active mountainous regions as well as a more accurate estimation of seismic risk for property and population. The results of such assessment for the most seismically active mountainous countries in Central Asia – Tajikistan and Kyrgyzstan will promote the sustainable development of the economy and population safety. In addition, the created GIS database will provide information to outline those areas that are most exposed to these multihazards and which would require more detailed analyses and monitoring of the risk affecting important industrial and social infrastructure in these areas. The special web-site will be created for this purpose, where the GIS data base, preliminary results of the project implementation will be discussed and reviewed by the participants and collaborators, and the final results of the project will be shared for anyone interested scientists and authorities
Meeting the ISTC goals and objectives. Since former “weapons” scientists took part in this Project implementation and because it is exceptionally peaceful, the Project meets the ISTC goals. Adherence to these objectives can be attained by a wide involvement of scientists and participating institutions through providing information on the Project during international conferences and workshops and a web-page.
Scope of activities.The following activities will be implemented in the frame of the Project:
- collecting geological, seismological and meteorological data including information about active faults, seismic catalogues, slope failures, debris flows, precipitation and temperature regime, most important industrial and social structure in pilot area(dams, big plants and cities, national parks, main infrastructures like roads, bridges, power lines and so on);
- creation of up-to-date GIS database for further analysis;
- using recent satellite imagery for upgrading the existing information about landslides, rock falls and debris flows;
- upgrading the existing deterministic seismic hazard maps based on the up-to-date methodology and techniques (spatial analysis of the seismic events and seismic sources, using the up-to-date ground motion prediction equations – GMPE - for estimation of seismic intensity);
- providing the modern probabilistic seismic hazard assessment (PSHA) for pilot area );
- analysis of the slope failures and debris flows distribution and their connection with most active seismic sources;
- analysis of the triggering effects of strong earthquakes for slope stability;
- construction of the matrix for multihazards analysis;
- creation of the maps of multihazards seismic impact for pilot area;
- based on the Project results, recommendations are provided for the national authorities for a safer land-use in mountainous areas;
- Presentation of results to the international scientific community.
Role of Foreign Collaborators/Partners. Group of scientists led by Dr. Eileen Vergino(Lawrence Livermore National Laboratory (LLNL), University of California) and Dr. Randolph J. Martin (New England Research, Inc. (NER)) expressed their wish to become Collaborators of this Project. The other Collaborators Dr. Conrad Lindholm (NORSAR Company, Norway) and Dr. Dino Bindi (GFZ, Germany) are engaged in the evaluation of seismic hazard using up-to-date techniques and methodology, Dr. Hans-Balder Havenith (Université de Liège Dep. Géologie - Géorisques et Environnement) is engaged in estimation of slope stability under seismic impact. We also plan to use the Skype based video-conferences for common discussions between collaborators and participants.
Technical approach and methodology. The main innovation of the Project work is the estimation of multihazards impact related to earthquakes for mountainous areas based on well-known facts from the past strong earthquakes around the World, and the use up-to-date techniques and approaches (GIS based spatial analysis, up-to-date GMPE, use DEM for slope failure analysis and so on). The calculation of seismic impact will take into account the logical connection between the intensity of Earth’s surface shaking and triggered slope failures based on the recent and modern scientific knowledge and methodology. The final maps of earthquake-induced multihazards and impacts assessment for the pilot area will be presented a numerical component that would strongly differ from existing approaches. The combined matrix based on the relation between risk-hazard-vulnerability for earthquakes and earthquake-triggered slope failures will be made as a result of project implementation (Re=f(He*Ve) and Rl=f(Hl*Vl)), i.e. RMH = feqs + flsd,
where R is a risk, V is a vulnerability and H is a hazard (e for seismic impact, and l for landslide impact – see further explanations below).
The more detailed methodology and approaches will be discussed during the first year of project implementation. The final maps will be based on such a matrix and will indicate the combined risk for every given cell. In case of good results this methodology and approach can be used in other mountain areas around the World.