Hydro-meteorological preconditions and geomorphological consequences of extreme flood in the small river basin in the wet subtropical zone (the Tsanyk River case study, Sochi region)

The overall increase in precipitation and the frequency of extreme rainfall is confirmed by several meteorological observations both on Black Sea coast Caucasus. In this context, research drivers an event becoming a severe flood geomorphological (erosion) becomes especially important. article analyses factors contributing to development flash watershed river Tsanyk (Great Sochi area) estimates its impact. Analysis hydrologic-meteorological situation during 7-9 September 2018 previous period showed that unique for investigated from hydrologic perspective. After prolonged without precipitation, 7-8 resulted with rapid water level rise (117 cm 40 min). We determined rates volumes channel erosion based repeated survey section, estimation speed length banks being flushed out, composed loose sediments bedrock using pin method. amount loosened average 2-3 times higher than flysch banks. At same time, material export one comparable (or even exceeds) total bank year, previously identified stationary observations.