NATO Project G4934 – Science for Peace and Security Program

Project participants:

University of Milan-Bicocca – Italy

Institute of Geophysics Tbilisi – Georgia

Geological Institute Baku – Azerbaijan

Michigan Technological University – USA

University of Portsmouth – UK

Kostanay Engineering and Economic University named after. M. Dulatova – Kazakhstan

 

Project description

This project is aimed at assessing the vulnerability to geological hazards of a highly strategic facility in the Republic of Georgia, represented by the country’s largest hydroelectric power plant: Enguri, and assessing the possible various scenarios of geological hazards that may arise, preventive measures that can be actually taken by the main participating end-users, as well as training activities that can be deployed to increase the capacity and know-how of young researchers and technicians from different countries. The Enguri HPP provides 75% of Georgia’s energy supply and is currently the second tallest arch dam in the world at 271.5 m. It is part of the Enguri HPP, partly located in Abkhazia, a breakaway region of Georgia. Problems with Enguri will affect energy distribution throughout Georgia, moreover, a possible spill from this reservoir will directly affect Abkhazia, where the villages of Jvari and Potskho Etseri (8,000 inhabitants in total, plus hundreds of rural settlements) are located. Several small landslides have occurred on the slopes near the reservoir, and on one side of the lake there is a huge Hoko landslide, the fall of which into the reservoir will cause a major emergency. In May 2014, near another site selected for the construction of a new reservoir, there was a huge landslide in the Darial Valley, which killed 8 people. Despite the very steep slopes surrounding the Enguri Reservoir and the high seismicity of the area, a quantitative assessment of slope stability in this area has not been carried out. Very high seismicity is due to the fact that the region is located at the foot of the Greater Caucasus mountain belt, along a swarm of active faults stretching from Georgia to the Caspian Sea. Although it is well known that seismicity can increase slope instability and cause landslides, a dynamic stability analysis of the slopes surrounding the reservoir has never been performed. Moreover, an updated assessment of the local maximum intensity of ground shaking during an earthquake, including the analysis of pre-instrumental earthquakes, has not yet been carried out. These data are of paramount importance for correctly quantifying the peak ground acceleration (PGA) caused by the strongest earthquake that can be expected here in the future. The acquisition of this seismic information, taking into account a sufficiently long historical seismic record, will allow us to conduct an up-to-date assessment of the security of vital infrastructures of strategic importance to Georgia.

 

The main objectives of the project are the following:

1) Reconstruction of prehistoric seismic activity of the main Quaternary faults near the Inguri HPP and calculation of the maximum paleoseismic magnitude;

2) Calculation of the expected GHA in the area by integrating modern seismicity data with paleoseismicity and local seismic coefficients;

3) Expand and supplement the currently limited instrumental earthquake catalogs of Georgia by including new paleoseismicity data;

4) Assessment of the static and dynamic stability of slopes using modern methods along the entire perimeter of the artificial reservoir;

5) assessment of possible scenarios of tsunami propagation after the failure of the investigated unstable slopes into an artificial lake and a possible dam break;

6) Assessment of a possible scenario of the consequences of flooding with overflow and flooding of material across the territory of Abkhazia and into the Black Sea;

7) Training activities including field exercises and instrumental knowledge as well as indoor sessions (at partner and NATO universities) in both paleoseismic research and landslide analysis to prepare young researchers and technicians for independent work and acquisition necessary skills for seismic hazard assessment, slope stability and flood analysis;

8) Engage end-participants and provide them with a GIS-based platform for immediate use of the information obtained in this project. Expected results include detailed maps and reports with all.