The creation of the reservoirs of the Angara HPP cascade caused enormous technogenic transformations of the geological environment and led to large-scale changes in its components and significant reconstruction of the entire set of conditions and factors. Indicators of the influence of the reservoir on the geological environment and its source itself are exogenous geological processes developing in the zone of influence of the reservoir. The article presents the results of long-term monitoring studies of the regime and conditions for local coastal geosystems functioning with exogenous processes complex that reflect the state of the natural environment its variation in space and time. Studies have shown that the shore zone of the Angara reservoirs, after long period of operation, has not yet reached the stage of stable equilibrium. Stable dynamics of abrasion is preserved, especially on shore slopes composed of loose sediments. The dynamics of block landslides displacement in the monitoring areas increased by several times: from 0,4–0,5 mm / year in natural conditions to 1,7–3,0 cm / year in technogenic conditions. It was established that the transformation of shore zone is enhanced as a result of geological processes interaction. New eolian-erosion, karst-erosion, abrasion-erosion mechanisms for the development of the erosional process not typical of natural conditions were formed. Karst processes are prominent. Maps of the current activity of the karst process in the southern part of the Bratsk reservoir for the last period of operation (since 2000) have been compiled. A burst of karst activity was noted in 2003, 2009 and 2011, which is closely related to periods of water level lowering after periods of its high standing. Two-stage model of landslide, erosion and abrasion process interaction at a high and low level in the reservoir are presented. Thus, the influence zone of the Angara cascade is high dynamic and determined by operational fluctuations in the reservoir water levels and is still undergoing transformation.

Kozyreva Elena Aleksandrovna, Candidate of Sciences (Geology and Mineralogy), Associate Professor, Head, Laboratory of Engineering and Geoecology, Institute of the Earth’s Crust, 128, Lermontov st., Irkutsk, 664033, Russian Federation, tel.: 8(3952)42-58-99, e-mail: kozireva@crust.irk.ru 

Babicheva Viktoriya Arkadjevna, Candidate of Sciences (Geology and Mineralogy), Research Scientist, Institute of the Earth’s Crust, 128, Lermontov st., Irkutsk, 664033, Russian Federation, tel.: (3952)42-58-99, e-mail: khak@crust.irk.ru 

Mazaeva Oksana Anatoljevna, Candidate of Sciences (Geology and Mineralogy), Research Scientist, Institute of the Earth’s Crust, 128, Lermontov st., Irkutsk, 664033, Russian Federation, tel.: (3952)42-58-99, e-mail: moks@crust.irk.ru

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