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At about 8:00 p.m. local time on 30 August 2020, a large-scale debris flow with an estimated volume of 3.2 million m3 struck Azijue Village in north-eastern Ganluo County, Sichuan Province, China. The debris flow killed three residents, buried two villages, damaged a local middle school, crushed three bridges, and interrupted a significant transportation line (the Chengdu–Kunming Railway) for 14 days. This catastrophic debris flow was successfully detected by local residents 2 h before the final large-volume deposits arrived, which provided enough time for most of the residents to evacuate ahead of the deadly geohazard. To characterise the evolution process of the Azijue debris flow, a detailed field investigation was conducted with the aid of remote sensing technology. The results demonstrated that the debris flow, which had a high viscosity and large density, was part of a geohazard chain. Localised precipitation in a high-relief mountainous area primarily dominated by a subtropical monsoon climate was the main triggering factor for the debris flow. Thick ancient diluvial deposit in the debris flow gully was one of the main environmental factors that facilitated the rapid mass enlargement and long-runout movement of the debris flow. The catastrophic downstream loss of lives and infrastructure can be attributed to a major secondary landslide that originated at the end of the second sub-horizontal diluvial platform and initiated by the combined effect of continuous rainfall, top overloading, and toe cutting by the rapid and dense debris flow. [ABSTRACT FROM AUTHOR]

The failure of the 2017 Xinmo catastrophic rockslide in Maoxian County, Sichuan, Southwest China was a combined effect of long-term and short-term triggering factors. Field investigation, historical data collection, laboratory tests, chemical and microstructure analysis and numerical simulations were adopted herein to reveal the initiation and failure mechanism of the Xinmo rockslide. The analytical results showed that this failure involved the coupling of several triggering factors. The initial cracks in the rock mass were induced by historical earthquakes due to the convex topography and the direction effect. Rock masses from the source area of the Xinmo rockslide contain water-sensitive minerals, i.e., albite and chamosite, and the easily oxidized chemical element Fe, resulting in obvious strength deterioration under the action of water. The scanning electron microscopy (SEM) experimental results indicated that the internal structure of the rock mass is conducive to weathering. The compressive and shear strengths of the rock mass were reduced due to freeze-thaw cycles and weathering. The antecedent rainfall further deteriorated the stability of the slope, and stress and deformation accumulated continually in the locked section. Finally, the locked section sheared out, and the slope failed. An entrainment effect was observed in the Xinmo rockslide due to the presence of old landslide deposits and the antecedent rainfall, resulting in an amplification of the catastrophic rockslide. A simplified three dimensional analysis model was established in this study to reveal the influence of the triggering factors on the failure mechanism of the Xinmo rockslide. [ABSTRACT FROM AUTHOR]

There are abundant moraine soil sources distributed in the Qinghai-Tibet Plateau of China, with complex historical causes, changeable material structure, and large differences in mechanical properties. Moraine landslide often occurs under the action of rainfall and ice and snow melting. The debris of landslide enters the gully and mixes with water flow, which is very easy to produce the moraine landslide--debris flow--dammed lake disaster chain, which is the key and difficult point of disaster prevention and reduction in the plateau. In recent years, the Sichuan--Tibet railway project and major hydropower development in Tibet have faced a great threat from the moraine landslide--debris flow--dammed lake disaster chain. It is a major national demand to improve the capacity of disaster prevention, reduction and relief. Moraine landslide--debris flow--dammed lake--dam-breaking flood is a chain disaster process of cascade amplification, which involves complex dynamic evolution mechanisms such as landslide initiation, movement behavior transformation, erosion amplification along the process, multi-stage river blocking superposition, and dam break water-sediment coupling. Especially under complex meteorological conditions, there are some problems such as unclear mechanism, inaccurate model, and lack of simulation technology. It is urgent to carry out the research on the complex dynamic mechanism, control theoretical model, and whole process numerical simulation of moraine landslide--debris flow--dammed lake disaster chain process. Combined with the research status at home and abroad, five research contents are further proposed: 1) Evolution of mechanical properties of moraine soil under complex meteorological conditions. 2) Dynamic disaster process and migration model of moraine landslide--debris flow. 3) Formation mechanism and simulation of moraine landslide--debris flow--dammed lake. 4) Mechanism of erosion and outburst of moraine dam and the process of flow channel expansion. 5) Mechanism of water-sediment interaction in the downstream channel and the simulation of flood evolution. Many preliminary explorations and research work have been carried out to preliminarily reveal the migration of moraine landslide debris flow and multi-stage river blocking mechanism, a dam break evolution model that can consider water erosion and intermittent collapse of the broken slope has been built, and the simulation method of moraine landslide--debris flow--dammed lake disaster chain evolution process has been discussed. The results lay a foundation for further understanding of the complex dynamic mechanism of the moraine landslide--debris flow--dammed lake disaster chain process, constructing the control theoretical model and developing the whole process numerical simulation system. And the results are expected to provide a theoretical basis for the mechanism of moraine landslide--debris flow--dammed lake disaster chain and technical support for non-engineering risk reduction and emergency disposal decision-making. [ABSTRACT FROM AUTHOR]

Prunus mira Koehne, a Prunus plant in the Rosaceae family, is named ཁམབུ། in Tibetan and "Guang he tao" in Chinese. It is mainly distributed in Tibet Autonomous Region, Yunnan Province, and Sichuan Province in China. It is also a rare "living fossil group" of peach genetic resources in the world. It is used in traditional Chinese medicine for the treatment of dysmenorrhea, injury, intestinal dryness, constipation, and other diseases, and is used in Tibetan medicine for the treatment of hair, eyebrows, and beard shedding. In this article, the botanical characteristics, medicinal history, modern applied research, and ethnobotanical investigation of P. mira were recorded and evaluated. P. mira was first recorded in Dumu Materia Medica. P. mira in Sichuan Province is mainly distributed in Ganzi Tibetan Autonomous Prefecture, and has certain economic and medicinal value. P. mira has high nutritional composition. It is made into high-quality edible oil, cosmetic base oil, fruit juice, fruit wine, fruit vinegar, "Liang guo", and other products. Oleic acid and linoleic acid are the main fat-soluble components of P. mira , which has an anti-inflammatory medicinal value and promotes hair growth. Its longevity and cold resistance can bring great genetic value and play an important role in maintaining peach genetic diversity. At present, there are few studies on the pharmacological effects of specific active components of P. mira and there are also few clinical studies. We can continue to study these aspects in the future. At the same time, products of P. mira have great market potential. All in all, P. mira is very worthy of further research and development. [ABSTRACT FROM AUTHOR]

Public participation in disaster preparedness and mitigation activities become an important part of disaster risk management. The impact of risk perception and protection motivation theory on preparedness in various types of disasters have been widely reported, and risk attitudes have similarly been studied as a factor influencing preparedness decisions. However, the adaptability of the results on the impact of risk perception on preparedness behavior was questioned in recent years. Especially in the field of geological disasters, very limited studies about the protection motivation theory and risk attitudes have been conducted in China. Therefore, this study designed a questionnaire of people's risk perceptions and the perception of protective measures based on the protection motivation theory and individual risk attitude factors. The involved field research was conducted in Ganluo County, Liangshan Prefecture, Sichuan Province in 2020. Based on the research data, the structural equation modeling method was used to analyze the effects of threat appraisal, coping appraisal and risk attitudes on people's willingness to engage in protective behaviors. The results show that individual coping appraisals have a significant effect on the willingness to engage in adaptive behavior, and the risk attitude factor added to the extended model also shows a significant effect on the willingness to prepare for disasters. The results of the study have important practical implications for the encouragement of multilevel participation in risk management in geological hazard-prone areas. [ABSTRACT FROM AUTHOR]

In the traditional Tibetan medicinal system, the medicinal parts of Nardostachys jatamansi (D.Don) DC. include the dried roots and rhizomes, which is effective in treating various diseases. In this study, molecular evolutionary analysis based on three markers (i.e. , ITS, matK and rbcL), and principal component analysis (PCA) combined with 1H NMR measurements were used to assess the genetic and chemical differences of the N. jatamansi from different habitats in Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China. The results showed that the ITS marker was highly effective to identify the intraspecific variation of N. jatamansi. Furthermore, the results of the chemical analysis indicated that the nardosinone and sucrose, as the metabolite landmarks, can distinguish the different habitats of N. jatamansi in Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China. Moreover, combining the chemical analysis with phylogenetic analysis, the results indicated that the metabolites differences may be affected not only by genetic structures but also by environmental factors. These findings provide valuable references for the effective protection and exploitation of N. jatamansi resources. • Using molecular evolutionary analysis and 1H NMR-PCA methods to assess the genetic and chemical differences of the N. jatamansi. • ITS marker was highly effective to identify the intraspecific variation of N. jatamansi. • Nardosinone and sucrose are the metabolic markers for the discrimination of N. jatamansi. • The metabolites differences may be affected not only by genetic structures but also by environmental factors. [ABSTRACT FROM AUTHOR]