Part I

Draft Black Sea Regional Transmission Project ESIA
lowland zone, scouring, flooding-accumulation dominate, while landslide and gullying
processes are negligible. In the hilly foothills the major processes are landslide and erosion.
In the low and medium mountains a zone-wide spectrum of geodynamic processes can be
observed.
The risk of earthquakes is high in this region, with seismic activity in the 7-8 magnitude zone
(Dzirula crystalline massif, Adjara-Imereti ridge, Okriba mountain massif). Landslides poses
serious risks to industrial and economical activities in the region, with the landslide damage
coefficient for Imereti estimated as 0.7-0.9.
Bank erosion (scouring) is observed in 229 areas in the region, with a total length of
527kilometers. Erosion affects arable lands, roads, bridges, irrigation hydrotechnical and
bank protection facilities, oil and gas pipelines, and cause damages to some. Gullying is
registered in 484 areas, with a total length of 257.3 kilometers.
Rock and scree avalanches (16 and 254 units respectively), are mainly concentrated in the
mountain regions in river headwaters and rocky areas of the ravines, as well as along the
slopes cut during road construction. Mudflows are less frequent, with 136 mudflow gullies
having been observed. Activation of the mudflow processes endangers some residential
areas including Chiatura and Sachkhere, as well as Baghdati, Sairme, Baghdadi- Sakreula,
Bagdati-Khani , Shorapan-Salieti, Sestaphoni-Rikoti, Khvani, Sachkhere road sections,
Tsipa-Lashi, Shorapan-Chiatura individual sections of the railroad, where stone-mud flows
hinder traffic.
Flooding and accumulation processes (spring-autumn) are observed in separate sections of
Sachkherte, Kolkheti and Akhalsopeli lowlands. There are 32 sections subject to flooding in
the region,. Floods damage arable lands, irrigation and hydrotechnical facilities, pipelines,
roads, protective engineering constrictions, industrial objects, settlements (including
Sachkhere, Zestaphoni, Kutaisi, Vani, and Samytredia residential areas and infrastructure).
In total flooded areas may reach hundreds of hectares.
In areas with carbonate rocks, karst processes are observed, with 121 units with different
forms of karst processes being registered in Khoni, Tskhaltubo, Terjola, Tkibuli, Chiatura,
Sachkhere and Kharagauli. They are rare in Vani and Samtredia areas.
Avalanches are occasionally observed in unpopulated high mountain areas of Kharagauli,
Badati, Vani, Tkibuli, Chiatura and Sachkhere regions. The area belongs to medium
mudflow risk (risk category 0.3-0.1) and high risk of landslides (risk category 0.9-0.7).
4.1.5.3 Seismic hazards
The Greater and Lesser Caucasus form the central Asian segment of the ‘Alpine-Himalayan
Fault and Fold Belt’Akhaltsikhe Basin. This belt extends from the Swiss Alps in southern
Europe to the Himalayan ranges of India and Nepal. The region is actively being deformed
by the collision of the African, Arabian, and Indian tectonic plates with the southern margin of
the Eurasian continent. The east-west trending faults are characterized by compressive
thrust movements. The north-east or north-west trending faults generally exhibit lateral
strike-slip movements.
Two types of fault movement are commonly observed along the study area, namely Reverse
and Thrust Faulting. Both are compressive styles of faulting and involve one fault block
pushing up and over the second fault block. The ‘thrust’ and ‘reverse’ designations are
distinguished by the dip angle of the fault plane. Thrust faults are characterized by dip
angles of less than 45 degrees, and Reverse faults exhibit dip angles of greater than 45
degrees.
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