Developmental and Distribution Characteristics and Formation Mechanisms of Large-Scale Landslide Disaster Chains in Bailong River Basin
Wang Gaofeng
Bi Yuanhong
Li Hao
Gao Youlong
Tian Yuntao
Chen Zongliang
Li Ruidong
Cong Kai
Fan Xiaopeng
Dong Hanchuan
Abstract：The Bailong River Basin is situated between two major left-lateral strike-slip faults:the East Kunlun Fault and the West Qinling Fault.Its unique geological setting makes it one of China's regions most prone to and severely affected by geological disaster chains,presenting an extremely critical situation for disaster prevention and mitigation.Based on data collection,remote sensing interpretation,and field surveys,this study established a database of 132 large-scale landslide disaster chains and systematically investigated their developmental characteristics,distribution patterns,and formation mechanisms.The research findings indicate:(1)All landslide bodies are large-scale or larger,exhibiting significant scale effects.Landslides within the 1 000×104-5 000×104m3 range account for 40.2％in number and 44.8％in total volume.High-position accumulation landslides predominate,with 24.2％displaying a"three-segment"anti-sliding topography.Landslides developed in the Devonian and Silurian soft-hard interbedded strata prone to sliding constitute 65％of the total landslide area;(2)Deformation is primarily characterized by multistage retrogressive deformation(often with local tension cracking-push deformation),progressive thrust-type landslides along fracture zones,and composite large-scale accumulation landslides.Over 60％possess long-runout mechanisms,exhibiting features of high-intensity granular flows dominated by long-duration creep;(3)Spatially,the landslides exhibit a banded concentration along major active faults and linear distribution along river systems.54.6％occur within 2 km of fracture zones,concentrated at fault offsets,bends,terminations,and intersections.Sliding directions are mostly parallel to fault strikes,with regional distribution controlled by NWW-NW trending and NE trending faults,coupled with the river network.(4)Their formation and development are primarily controlled by active faults,landslide-prone strata(including phyllite),and the differential mid-high mountain gorge topography.Regional long-duration(5-15 days)heavy rainfall is the main triggering factor,exhibiting a lag effect.The frequency and scale of disasters increased significantly 1.5 to 5 years after earthquakes.The research results provide important guidance for enhancing the understanding of the formation mechanisms of catastrophic landslide disaster chains in the northeastern margin of the Tibetan Plateau and improving disaster prevention and mitigation capabilities.
Keywords：geological disaster chainlandslide disasterdevelopment and distribution characteristicsformation mechanismBailong River Basinengineering geology
Publication Date：2025-10-30
Online Publishing Date：2025-11-11(First online date of this platform, not the publication date of the document)
Pages：20( 3885-3904 )