Ecological Systems and Devices Annotation << Back AVALANCHE HAZARD OF NATURAL AND MAN-MADE COASTAL AVALANCHE COMPLEXES FOR HIGHWAYS OF SOUTH SAKHALIN E.N. Kazakova At present, in South Sakhalin, in terms of the length of the avalanche hazardous zones and the frequency of avalanches the most damage to highways is caused by avalanches from natural and man-made avalanche complexes of marine terraces and cliffs. Avalanche catchments here have a relative height of no more than 200 m, the average volume of avalanches rarely exceeds 1.5 thousand m3, and the avalanche run out distances rarely exceeds 500 m. However, the roads of South Sakhalin for many kilometers are laid directly at the foot of avalancheprone slopes, so even small avalanches can cause damage to vehicles and cause loss of life. Regular blockages of the roadbed in these parts of highways temporarily block communication between settlements and require significant economic costs for clearing. The most avalanche hazardous parts of roads are located in the Nevelsky district: Shebunino – Nevelsk (length 22 km, 82 % of the length of this part are avalanche hazardous) and Kalinino – Nevelsk (length 15 km, 80 % of the length of this part are avalanche hazardous). For these areas, morphological and morphometric characteristics of avalanche catchments, as well as avalanche parameters (volume, frequency, maximum run out distance) were determined. Avalanche safety on roads exposed to avalanches from sea terraces is currently a serious problem due to the scale of the work required. Due to the large length of avalanche hazardous zones, it is very difficult to provide avalanche protection for all dangerous parts of roads. Keywords: avalanche, avalanche hazard, coastal avalanche complex, Sakhalin Island. DOI: 10.25791/esip.6.2023.1373 Pp. 03-11.