Ecological Systems and Devices Annotation << Back FORMATION OF TIMBER DRIFTING ON THE DEBRIS FLOW OF SAKHALIN ISLAND S.V. Rybalchenko The paper considers the regional features of the phenomena of timber drifting on the debris flow rivers of Sakhalin Island, the regularities of seleforming on the Sakhalin rivers and their mudfl ow regime are established, the factors of formation of timber drifting characteristic of the debris flow watercourses of Sakhalin Island are studied. Due to the history of the formation of the Sakhalin terrane and the macrorelief of the territory, the main mountain structures are composed of marine sediments, which leads to selenity of rivers, the active development of slope exogenous processes in the sides of watercourses, which ensure the flow of solid phase and woody vegetation into the channel and talvegs. Also, regional features include a large amount of liquid precipitation, the annual amounts of which in the valleys and on the coast are 800–1200 mm, and in mountainous areas can reach 1500–2000 mm. The main rock composition of timber drifting is represented by broad-leaved rocks (willow and alder), which, unlike softwood timber drifting, are more prone to the formation of creases and are most dangerous for culverts. Keywords: debris flow, timber drifting, logjams, slope exogenous processes, riverbank erosion. DOI: 10.25791/esip.2.2023.1355 Pp. 46-55.