Conditions of the formation of the main exogenous processes in the southwest part of the Baikal rift system (Russia) and in the eastern part of the south China block (China)

The aim of the study is to analyze and compare the causes and conditions for the formation of the exogenous processes in the southwestern part of the Baikal rift system (Russia) and in the eastern part of the South China block (China) with the emphasis on the weathering, gravitational and surface-water processes. The Tunka rift zone is taken as the main site. It is compared with the eastern part of the South China block where the main observation points are associated with the Yangtze River delta and adjacent territories. The main research methods include field routes with visual examination of the observation points and measurement of certain characteristics and parameters, as well as selection and analysis of the published and archive literary sources. The comparison of the geodynamic processes emerging in the study territories has concluded that the dominant processes are weathering and gravitational processes, namely, landslide formation. The intensity of the processes is primarily determined by the sharply broken relief. The differences between the two study regions are determined by the climatic peculiarities including the precipitation level and temperature change, as well as by the seismicity, the presence of the glacier forms, and the landscape features. The combination of the above factors predetermines the wet landslide activity of the Tunka branch of the rift depressions vs. almost none of the kind in the Yangtze River delta. The analysis of the defined factors makes it possible to predict exogenous processes such as landslide and mudslide, and take timely measures on minimizing the negative impact of the above. The lack of the large scale maps showing the danger zones and adequate control of identifying the land areas that are knowingly in need of protection from the geodynamic processes’ impact, are increasingly leading to the extension of the danger zones and associated risk both in the eastern part of China and throughout the Baikal region.

exogenous processes, weathering, landslide, mudslide, Baikal region, Eastern China