MORPHOLOGY, DEFORMATIONS AND TEMPORARY MODIFICATIONS OF THE LENA RIVER CHANNEL AND ITS INFLUENCE ON THE YAKUTSK ECONOMIC INFRASTRUCTURE
Reconfiguratings of the Lena river bed near Yakutsk city (one of the most complex part of the river concerning channel deformations) have directional character, and it caused gradual river drift away from the city. Development of the right-hand tributaries system mostly occurred near Yakutsk, meanwhile the left-handed ones (where the city is situated) grow shallow, and it leads to troubles in operation of municipal water intakes, water accesses to the city, complication of navigability etc. Nowadays the Lena river development is defined by: 1) transforming of the adjacent tributaries into parallel-channeled ones near Yakutsk, upfront not-forks in upper reaches and alternate one-sided forks in the lower reaches; 2) multidirectional river channel shift near Yakutsk - towards right with the right branch development, and towards left with development of shallow bend - on the adjacent section in upper reaches; 3) transgressive shift of the flood-plain island massives - its washaway from the heads and extension of the downstream ends, which lead to the shallowing of left branch (Adamovsky channel) near Yakutsk and development of the right-hand channel here. General regularities of the river bed reconfiguratings allowed to elaborate the trial scheme of recommendations to castigation of the present negative situation on the Lena river near Yakutsk city based on the river processes management and formation of conditions for its development in right direction, as well as to validate the program of detailed researches for the mathematic modelling of the river bed reconfigurations and engineering of hydrotechnical measures.