Propagation characteristic of debris avalanches and dynamic effects of curvature terrain under complex topography in China
摘要
The types, propagation, and scales of catastrophic geohazard were closely associated with geomorphic units. This paper systematically analyzed the characteristics of catastrophic geohazard in the orogenic belts of the Qinghai-Tibet Plateau, Periphery of the Qinghai-Tibet Plateau, and the Yangtze Platform, which also revealed the impact of gully curvature on debris avalanche movement, combined with topographic and geomorphic analyses, statistical movement parameters, and physical model experiments. The research findings indicated that the geohazard types in the orogenic belts of the Qinghai-Tibet Plateau were predominantly rockslides, rock-ice avalanches, and ice avalanches, disaster volumes exceeding 10 million m3 and movement distances exceeding 5 km. Additionally, geohazards in this region often occur with temperature changes, tectonic patterns, and extreme heavy rainfall. Geohazards were primarily characterized by rockfall and rockslides in the Yangtze Platform, with the deposits volume ranging between 5 × 105 and 1 × 106 m3 and movement distances below 2 km. The sliding bodies in this area were generally influenced by factors such as structural planes, tectonic forms, and topographic conditions, exhibiting five types structures. For various curved movement paths, there has been some decrease in velocity with long movement distance and high length-to-width ratio of the deposits as the curvature of the path increased. Compared to straight movement paths, curved paths enhance the lateral momentum transfer of debris particles while weakening the longitudinal momentum effect. This study between the geohazard chains and gully topography may be considered in hazard assessment and dynamics of high mountains.