Transformation of accumulative landforms in the area of the Selenga river delta under the influence of changes in Baikal level
E.G. PERYAZEVA, A.M. PLYUSNIN, A.V. UKRAINTSEV
Dobretsov Geological Institute, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, Russia
Keywords: abrasion and accumulation processes, Lake Baikal level rise, sand formations, sedimentation, bank erosion
Abstract
This article provides a substantiation for the transformation of the Lake Baikal coast in the area of the Selenga river under the effect of abrasion and accumulation processes associated with the Lake Baikal level rise during the construction of the Irkutsk hydroelectric power plant. It is shown that in the first years after the runoff regulation, an intense erosion of the entire coast occurred. On the basis of processing and comparing cartographic material from different years it was found that there occurred a significant decrease in the length and area of islands, peninsulas and sand bars in the Sor and Cherkalova Sor bays and in the Selenga delta. At present, destruction of sandy islands in the mouths of the rivers and the transport of sandy material along the coast continue during the autumn storms. It is shown that the decrease of the Selenga delta surface is associated with changes in sedimentation conditions. Coarse fraction of the solid runoff began to accumulate in the middle delta, and only fine suspended material enters the lake delta.
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