ИСТИНА

The study is dedicated to extreme exogenous processes (EEP) associated with the accumulation and movement of clastic material – landslide-talus and debris flows, being cyclical and are subject to the complex effect of several factors. The novelty is their joint consideration. The cycle of EEP development, during which some processes stipulate each others, can last for several years. We analyze the main factors in the formation of EEP: air temperature, precipitation, frost weathering and seismicity at the end of the previous cycle and during the current one in the Cherek Balkarsky river basin, where we conduct monitoring research since 2009. It is assumed that the processes associated with the accumulation and movement of clastic material - landslidetalus, talus and debris flows are cyclical and are subject to a complex effect of several factors. Novelty of the research is in joint consideration of these factors. Here the cycle is between 3 and 6 years. Large debris flows in the study area descended in July 2017, before that – in the summer of 2012. The cycle of EEP, such way, lasted 5 years. The prerequisites for its completion in the summer of 2017 were joint activity of several factors, and, to a large extent, not immediate, but early. And already in July, large gatherings were preceded by a significant increase air temperature, which, thus, served as a «trigger», and a violent summer flood. Since then, there has been an accumulation of debris material - local landscapes go through the next cycle. Air temperature variation in winter 2019/20 was not quite traditional for the cold season in the study area. Average monthly values of November and December were the usual. However, the transition from warm the cold season was sharp. Summer of 2019 was cool – its values are unusually low for this time. Moreover, the coldest month of summer was July, traditionally the warmest. The low July temperature neutralized the abundant precipitation that fell this month in terms of their contribution to the EEP activity: the melting of glaciers and snowfields in the highlands was weak. Winter 2019/20 was extremely little snow. Accordingly, the avalanche activity this season was very weak. The channel processes in spring 2020 are also poorly developed. Seismic activity in 2019 in the study sites did not appear. Thus, the state of the main EEP factors in 2019 did not contribute to the active flow of the latter and the accumulation of debris. Factor indicators in the winter season 2019/20 suggest a low activity of EEP in the summer of 2020.