THE FORMATION PROCESS,SOIL-FORMING CHARACTERISTICS,AND LANDSLIDE DISASTER MECHANISM OF MORAINE IN HIGH-MOUNTAIN GLACIER REGIONS
After glacier transport,accumulation,and ablation,moraine soil constitutes the primary product in high-mountain glacier areas on the edge of the Qinghai-Tibet Plateau in China.Influenced by the topography and extreme climate of these regions,it exhibits characteristics such as wide gradation,strong penetration,heterogenei-ty,non-sorting,and non-bedding.Moraine soil serves as the principal material source contributing to the geological disaster of moraine landslides in high-mountain glacier areas.Systematically understanding the formation process and disaster evolution characteristics of moraine soils in alpine mountain areas is of great practical value for a scien-tific comprehension of disaster pregnancy mechanisms.To achieve this,the study begins by discussing glaciation and moraine geomorphology characteristics in alpine mountain areas.It then clarifies the evolution process and de-velopment conditions of moraine soil,analyzing the distribution characteristics of moraines in high-mountain glacier areas on the margin of the Qinghai-Tibet Plateau in China.Next,the study summarizes related classification indica-tors of moraine soil and discusses typical soil-forming characteristics under different deposition positions,deposition times,and genesis.Finally,the main disaster-causing factors and structural characteristics of moraine landslides are examined,and the development characteristics and disaster evolution process of moraine landslides under extreme climate conditions are analyzed.The findings indicate that:(1)The development of moraine soil in high-mountain glacier areas is primarily influenced by glacial ice advance and retreat,prevalent in the western high-altitude region and areas with clustered high-mountain systems exhibiting distinct vertical climate changes.(2)Moraine structures differ based on deposition positions and times,revealing regional variations.Modern moraines at high-altitude glac-ier sources exhibit loose structure,poor circularity,and undeveloped bedding,while ancient moraines with a broad altitude span feature relatively dense structure.(3)Various failure modes of interfacial landslides induced by differ-ent moraine slope structures include shallow surface moraine fall/meltwater creep,ice water accumulation,and ancient moraine layer interface control.The water-holding and slip-promoting effect of the ice-rich zone emerges as the primary cause of landslide disasters at the moraine soil interface.This study aims to provide a fundamental refer-ence for understanding the characteristics of moraine land quality and the mechanisms underlying landslide disasters in high-mountain glacier areas.
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