THE AUTUMN 2023 MASSIVE MUDFLOW EVENTS FORMATION IN THE MINOR RIVERS BASINS OF THE SUSUNAI RANGE AREA

Heavy rainfall on the night of August 31 – September 1, 2023, caused massive mudflows in the area of the Susunai range near Yuzhno-Sakhalinsk. Such large-scale mudflows have not occurred since 1981. Another intense rainfall in early October 2023 has once again resulted in mudflows. This paper describes the condition of 13 mudflow channels after these events, presents the mudflow parameters, and provides a list of mudflow-caused damages. Special attention has been given to the mudflow initiation mechanism. The paper also confirms the data on recurrence frequency of massive large-scale mudflows in the Susunai range area.