Ecological Approach to Assessing the Causes and Consequences of the Winter Landslide on the Bureya Reservoir

The thawing of permafrost in the north of Siberia and the Far East is accompanied by hazardous geoogical phenomena (landslides, sink-holes, floods, etc.) which present a threat to the infrastructure of the region and lead to a change in the natural water quality. In December 2018, at the temperature of ‒32 ℃, a giant landslide occurred on the shore of the Bureya reservoir, which cut off access of water to the Bureya hydroelectric power station. To restore the hydrologial regime, explosives were used, which also affected consideraby the composition of water in its interaction with crushed rocks. Risk factors were represneted by toxic volatile compounds (benzene, methanol, toluene, and xylene). As a result of destruction of soil coverof the coastal zone and biochemical processes at the interaction of water with rocks, considerable changes were observed in the behavior of a number of elements (As, Pb, Fe and Co). Ecological risks of change in the water composition are associted with input of a large volume of crushed rocks, vegetable debris, detonation products of explosives, and with an intensification of biogeochemical processes. They are accompanied by input of toxic organic matter, gases and elements into the water. It is necessary to conduct a comprehensive survey of the steep shores of the Bureya reservoir and organize a monitoring of the potential emission of methane in order to prevent hazardous natural phenomena associated with the thawing of permafrost.