Home – Home – Jornals – Geography and Natural Resources 2022 number 5S

The natural preconditions for the development of various morphogenetic types of estuarine systems of the main tributaries of Baikal are considered. The objective of this study was to examine the estuarine areas and adjacent shores of the lake, the development of which is largely due to fluctuations in the current level of the lake-reservoir. The river mouth systems are represented by a complex of subaerial and subaquatic accumulative-erosive landforms and their sediments formed by a river and the lake within the river mouth at the present stage. Within the estuarine areas, there is a wider range of landforms created during the more ancient stages of interaction in the river - sea system. The main recent factors in the development of the estuarine systems of Baikal include fluctuations in the level of the reservoir, wave activity, alongshore currents, and the associated sediment transport and river runoff. The preconditions for the formation and development of various morphogenetic types of estuarine systems are the geological and tectonic features of the coast, which in turn are predetermined by the positive and negative morphostructural elements of the Baikal rift zone as well as by the layer of loose deposits. In addition, tectonic structures determine the nature of the interaction of river flows at the contact with the waters of the receiving reservoir in conditions of deep or shallow near-shore zone. The relationship between the development of morphogenetic varieties of river mouths and the morphostructural features of the marginal elements of the Baikal rift zone, the geometric pattern of the coasts, the slopes of the seashore, and also the ordinal structure of the river system has been determined. The estuarine systems of Baikal undergo multidirectional changes during periods of different water levels, which correspond to the formation or degradation of coastal landforms and channel deformations in the lower reaches of tributaries. An integrated scheme has been developed, which combines the dynamic and morphogenetic classifications of coasts and the types of mouth for the Baikal tributaries. A schematic map of the morphogenetic types of estuaries and the geological and tectonic preconditions for their formation is presented.