Morphodynamics of the confluence of the Svicha and Sukil rivers

SUMMARY With the development of GIS technologies and remote sensing in international research, the study of the morphology and dynamics of the confluence of both large and small rivers is gaining considerable popularity. Confluence nodes are special hydro-geomorphological elements of river systems. Their morphodynamics determines the development of horizontal and vertical deformations of confluent rivers’ riverbeds and affects the economy and infrastructure in the region of confluence, especially in mountainous and foothill areas. The purpose of the present study is to assess the morphodynamics of the Sukil-Svicha confluence within the period of 1880–2021 and to reveal its causes and consequences. To achieve this purpose, topographic maps, space photographs, and UAV surveys were used. According to the results of the study, three periods of the morphodynamics of the Sukil-Svicha confluence node were identified: the first one embraces 1880–1984 (maximum horizontal displacements over 3 km); the second one — 1984–2001 (maximum displacements up to 750 m); the third period covers 2001–2021 (stabilization and formation of present junction morphology; maximum displacements — 25–50 m). The main reasons for the riverbed morphodynamics during these periods are analyzed.