Characteristics and risk assessment of debris flow in northeast tibetan plateau

Based on the principle of fuzzy matter-element analysis, the concept of information entropy is introduced to establish a fuzzy matter-element evaluation method. This method is utilized to comprehensively evaluate the degree of debris flow. The classifications of debris flow are regarded as the objects of matter-element and their indexes for evaluation as well as the corresponding fuzzy values are used to construct the composite fuzzy matter-elements. By calculating the relevancy the comprehensive evaluation of debris flow can be carried out. This model is applied to analyze the degree of debris flow in the practical application. The application shows that the model is effective and practical.

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Heavy metal concentrations and ecological risk assessment for surface sediment of Da Qaidam Salt Lake in Qaidam Basin, northern Tibetan Plateau

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/513/1/012069 ◽

2020 ◽

Vol 513 ◽

pp. 012069

Author(s):

Chunliang Gao ◽

Junqing Yu ◽

Xiuyun Min ◽

Aiying Cheng

Keyword(s):

Risk Assessment ◽

Heavy Metal ◽

Tibetan Plateau ◽

Ecological Risk ◽

Ecological Risk Assessment ◽

Surface Sediment ◽

Salt Lake ◽

Qaidam Basin ◽

Heavy Metal Concentrations ◽

Northern Tibetan Plateau

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Risk assessment of debris flow based on group decision making – A case study of Luanchuan County, Henan Province, China

MATEC Web of Conferences ◽

10.1051/matecconf/201817504025 ◽

2018 ◽

Vol 175 ◽

pp. 04025

Author(s):

Pengyu Chen ◽

Ying Kong

Keyword(s):

Risk Assessment ◽

Decision Making ◽

Debris Flow ◽

Group Decision Making ◽

Debris Flows ◽

Large Scale ◽

Group Decision ◽

Henan Province ◽

Comprehensive Assessment ◽

Material Sources

Luanchuan County, located in the mountains of Western Henan Province, is characterized by poor geological environment and abundant material sources and rainfalls. Debris flows have occurred many times in this county, and in some gully debris flows exhibit a large scale, requiring risk assessment. In the multi-factor comprehensive assessment methods for debris flow risk, it is really important to determine the weight of each factor since this affects the reliability of the assessment results. Given that the subjective weighting method can accurately reflect the importance of each factor, in order to improve the reliability of subjective weighting, the group decision making method is used to determine the weight of each factor. Group decision making is realized using the analytic hierarchy process and the data fusion algorithm. In this method, the expert combination weight is determined; on this basis, a model for comprehensive assessment of debris flow risk is established by the linear weighted sum method, and risk assessment is performed for gullies with medium to large-scale debris flows in the study area. The assessment results show that all debris flow gullies face minor to moderate risks. For gullies with high risk degree, it is suggested to timely clear material sources in channels and construct or reinforce retaining dams in order to prevent re-occurrence of debris flows.

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Event-based probabilistic risk assessment of livestock snow disasters in the Qinghai–Tibetan Plateau

Natural Hazards and Earth System Science ◽

10.5194/nhess-19-697-2019 ◽

2019 ◽

Vol 19 (3) ◽

pp. 697-713

Author(s):

Tao Ye ◽

Weihang Liu ◽

Jidong Wu ◽

Yijia Li ◽

Peijun Shi ◽

...

Keyword(s):

Climate Change ◽

Risk Assessment ◽

High Risk ◽

Tibetan Plateau ◽

Return Period ◽

Probabilistic Risk Assessment ◽

Future Climate Change ◽

Tibet Autonomous Region ◽

Event Based ◽

Probabilistic Risk

Abstract. Understanding risk using quantitative risk assessment offers critical information for risk-informed reduction actions, investing in building resilience, and planning for adaptation. This study develops an event-based probabilistic risk assessment (PRA) model for livestock snow disasters in the Qinghai–Tibetan Plateau (QTP) region and derives risk assessment results based on historical climate conditions (1980–2015) and present-day prevention capacity. In the model, a hazard module was developed to identify and simulate individual snow disaster events based on boosted regression trees. By combining a fitted quantitative vulnerability function and exposure derived from vegetation type and grassland carrying capacity, we estimated risk metrics based on livestock mortality and mortality rate. In our results, high-risk regions include the Nyainqêntanglha Range, Tanggula Range, Bayankhar Mountains and the region between the Kailas Range and the neighbouring Himalayas. In these regions, annual livestock mortality rates were estimated as >2 % and mortality was estimated as >2 sheep unit km−1 at a return period of 20 years. Prefectures identified with extremely high risk include Guoluo in Qinghai Province and Naqu, and Shigatse in the Tibet Autonomous Region. In these prefectures, a snow disaster event with a return period of 20 years or higher can easily claim total losses of more than 500 000 sheep units. Our event-based PRA results provide a quantitative reference for preparedness and insurance solutions in reducing mortality risk. The methodology developed here can be further adapted to future climate change risk analyses and provide important information for planning climate change adaption in the QTP region.

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