NATO Project

Project participants:

Italy – University of Milan – Bicocca

Georgia – Tbilisi Institute of Geophysics

Azerbaijan – Baku Geological Institute

United States – Michigan Technological University

United Kingdom – University of Portsmouth

Kazakhstan – Kostanay Engineering and Economics University named after M. Dulatov 

Project description

This project aims to assess the vulnerability to geological hazards of a highly strategic facility in the Republic of Georgia, represented by the country's largest hydroelectric power plant on the Inguri River, and to evaluate various possible scenarios of geological hazards that may arise, preventive measures that can be realistically taken by the main end users involved, as well as training activities that can be deployed to enhance the capacity and know-how of young researchers and technical specialists from different countries. The Inguri HPP provides 75% of Georgia's energy supply and is currently the second highest arch dam in the world at 271.5 m. It is part of the Inguri HPP, which is partially located in Abkhazia, a separatist region of Georgia. Problems with Inguri 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 are located (a total of 8,000 inhabitants, plus hundreds of rural settlements). Several small landslides have occurred on the slopes near the reservoir, and on one side of the lake there is a huge landslide called ‘Hoko’, which, if it falls into the reservoir, will cause a major emergency. In May 2014, a huge landslide occurred in the Darial Valley near another site selected for the construction of a new reservoir, killing eight people. Despite the very steep slopes surrounding the Ingur Reservoir and the high seismicity of the area, no quantitative assessment of slope stability in this area has been carried out. The very high seismicity is due to the fact that the area is located at the foot of the Greater Caucasus mountain range, along a series 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 analysis of the stability of the slopes surrounding the reservoir has never been carried out. Furthermore, an updated assessment of the local maximum ground motion intensity during an earthquake, including an analysis of pre-instrumental earthquakes, has not yet been carried out. This data is of paramount importance for the correct quantitative assessment of peak ground acceleration (PGA) caused by the strongest earthquake that can be expected here in the future. Obtaining this seismic information, taking into account the fairly long historical seismic record, will allow us to conduct a modern assessment of the safety of vital infrastructure that is of strategic importance to Georgia.

The main objectives of the project are as follows:

1) Reconstruction of prehistoric seismic activity of major Quaternary faults near the Ingur Hydroelectric Power Plant and calculation of maximum paleoseismic magnitude;

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

3) Expanding and supplementing the currently limited instrumental catalogues of earthquakes in Georgia by including new paleoseismicity data;

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

5) Assessing possible scenarios for the spread of a tsunami after the collapse of the unstable slopes under investigation into the artificial lake and a possible dam breach;

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 classes (at partner universities and universities in NATO countries) on both paleoseismic studies and landslide analysis, to prepare young researchers and technicians for independent work and to acquire the necessary skills for seismic hazard assessment, slope stability and flood analysis;

8) Engage end users 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 the data necessary for quantitative assessment of seismic and landslide hazards, as well as a report describing various possible scenarios.