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泥石流颗粒的标度分布 被引量:14
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作者 李泳 谢江 +1 位作者 周小军 郭晓军 《四川大学学报(工程科学版)》 EI CAS CSCD 北大核心 2013年第1期1-7,共7页
大多数泥石流由宽粒径颗粒组成,粒径介于10–3~102mm。通常以个别特殊粒径(如D10、D30、D50等)或其组合(如均匀系数、曲率系数等)来刻画颗分的性质,但这些都是经验性参数,没有明确的物理意义,也不能确定颗分曲线的函数形式。选取蒋家... 大多数泥石流由宽粒径颗粒组成,粒径介于10–3~102mm。通常以个别特殊粒径(如D10、D30、D50等)或其组合(如均匀系数、曲率系数等)来刻画颗分的性质,但这些都是经验性参数,没有明确的物理意义,也不能确定颗分曲线的函数形式。选取蒋家沟典型黏性泥石流流体样本和国内各泥石流多发区泥石流堆积土体样本,通过粒度分析,运用Matlab和函数逼近方法,发现泥石流颗粒普遍满足一种标度分布:P(D)=CD-μexp(-D/Dc),因而颗分性质可以用自然参数μ和Dc来刻画。μ刻画了土体在自然状态下的孔隙度,Dc是一个特征粒径,代表颗粒组成的范围。根据蒋家沟大量泥石流样本发现,μ<0.10,而对高容重泥石流,μ<0.05。泥石流容重随Dc呈幂函数增长,Dc从而刻画了泥石流的输移能力。由此确立了分布参数与泥石流性质的关系,并将其用于汶川震区泥石流的评估。 展开更多
关键词 泥石流 颗分曲线 标度分布 分布参数 泥石流评估
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颗粒组成与泥石流运动的涨落 被引量:5
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作者 李泳 苟万春 +1 位作者 王保亮 刘道川 《山地学报》 CSCD 北大核心 2016年第4期468-475,共8页
泥石流物源、流体和堆积物的颗粒分布满足P(D)=CD^(-μ)exp(-D/Dc),其中参数C,μ和D_c由传统的粒径分布特征决定。μ随细颗粒(特别是粘粒)含量的增大而增大,D_c刻画粒径的范围,且随粗粒含量而增大。蒋家沟泥石流的观测表明,同一场泥石... 泥石流物源、流体和堆积物的颗粒分布满足P(D)=CD^(-μ)exp(-D/Dc),其中参数C,μ和D_c由传统的粒径分布特征决定。μ随细颗粒(特别是粘粒)含量的增大而增大,D_c刻画粒径的范围,且随粗粒含量而增大。蒋家沟泥石流的观测表明,同一场泥石流包含着数十到数百个不同性质、流态和规模的阵流。阵流的涨落和多样性是与流体的颗粒组成密切相关的。一定的颗粒组成对应着一定的饱和颗粒浓度,决定一定的饱和流体状态。阵流的涨落,是在没有达到饱和状态时的随机运动的状态。阵流涨落随D_c增大而趋于平缓;当流体达到饱和态时,阵流达到最大的流深、流速和流量,且与颗分参数(μ,D_c)具有幂函数关系。运用本文的方法,可根据颗分参数来预估泥石流的性质和规模。 展开更多
关键词 泥石流演化 颗粒分布 随机过程 动力学参数 泥石流评估
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Risk Assessment of Highways Affected by Debris Flows in Wenchuan Earthquake Area 被引量:21
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作者 CUI Peng XIANG Ling-zhi ZOU Qiang 《Journal of Mountain Science》 SCIE CSCD 2013年第2期173-189,共17页
Since the Wenchuan earthquake in China on May 12th, 2008, highways in earthquake-affected areas have been frequently interrupted by debris flows. We analyzed the hazard effect modes and damage processes along highways... Since the Wenchuan earthquake in China on May 12th, 2008, highways in earthquake-affected areas have been frequently interrupted by debris flows. We analyzed the hazard effect modes and damage processes along highways and developed three key indexes, scale of debris flows, deposits on highways and river blockage, to describe quantitatively the highway disasters. By combining the empirical methods and the actual terrain conditions, we proposed new methods to determine the value of hazard indexes. In addition, we used the economic value and resistance of highway as vulnerability assessment indexes, then determined the specific subindexes for the subgrade, bridges and culverts, and developed a way for the quantified vulnerability zoning. Moreover, we proposed the assessment and mapping methods for highway risk. The risk is described into 5 grades: extremely low risk, low risk, middle risk, high risk and extremely high risk. We applied these methods in a case study carried out on provincial highway S3o3 from Yingxiu Town to Wolong Town, in Wenchuan County. Analysis of debris flow risk for the whole highway, showed that the total length of highway in extremely low risk area was 28.26 km, 4.83 km in low risk area, 8.0 km in middle risk area, 3.65 km in high risk area, and 3.06 km in extremely high risk area. The assessment results are consistent with the field survey data which reflected the disaster situation. This risk method can be used objectively to evaluate the debris-flow risk along highways, and is useful for highway reconstruction in mountainous areas suffering from active debris flows. 展开更多
关键词 Debris flow Highway disaster Hazardanalysis Vulnerability analysis Risk analysis Wenchuan earthquake
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Comparison between FLO-2D and Debris-2D on the Application of Assessment of Granular Debris Flow Hazards with Case Study 被引量:24
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作者 WU Ying-Hsin LIU Ko-Fei CHEN Yi-Chin 《Journal of Mountain Science》 SCIE CSCD 2013年第2期293-304,共12页
Numerical simulation has been widely applied to the assessment of debris flow hazards. In East Asia and especially Taiwan, the most widely used numerical programs are FLO-2D and Debris-aD. Although these two programs ... Numerical simulation has been widely applied to the assessment of debris flow hazards. In East Asia and especially Taiwan, the most widely used numerical programs are FLO-2D and Debris-aD. Although these two programs are applied to the same engineering tasks, they are different in many aspects. These two programs were compared according to their fundamental theories, input and output data, computational algorithms and results. Using both programs, the simulations of a real debris flow with abundant granular material induced by landslides at Xinfa village in southern Taiwan are performed for comparison. The simulation results show that Debris- 2D gives better assessment in hazard area delineating and flow depth predicting. Therefore, Debris-2D is better for simulation of granular debris flows. 展开更多
关键词 Debris flow assessment Programcomparison FL0-2D Debris-2D
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Forecast Method of Multimode System for Debris Flow Risk Assessment in Qingping Town,Sichuan Province,China 被引量:3
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作者 KONG Jiming 《Journal of Mountain Science》 SCIE CSCD 2011年第4期592-602,共11页
The Wenchuan Earthquake of May 12,2008 triggered large numbers of geo-hazards.The heavy rain on 13 August 2010 triggered debris flows with total volume of more than 6 million cubic meters and the debris flows destroye... The Wenchuan Earthquake of May 12,2008 triggered large numbers of geo-hazards.The heavy rain on 13 August 2010 triggered debris flows with total volume of more than 6 million cubic meters and the debris flows destroyed 500 houses and infrastructure built after the Wenchuan Earthquake.The study area Qingping Town was located in the northwestern part of the Sichuan Basin of China,which needs the second reconstructions and the critical evaluation of debris flow.This study takes basin as the study unit and defines collapse,landslide and debris flow hazard as a geo-hazard system.A multimode system composed of principal series system and secondary parallel system were established to evaluate the hazard grade of debris flow in 138 drainage basins of Qingping Town.The evaluation result shows that 30.43% of study basins(42 basins) and 24.58% of study area,are in extremely high or high hazard grades,and both percentage of basin quantity and percentage of area in different hazard grades decrease with the increase of hazard grade.According to the geo-hazard data from the interpretation of unmanned plane image with a 0.5-m resolution and field investigation after the Wenchuan Earthquake and 8.13 Big Debris Flow,the ratio of landslides and collapses increased after the Wenchuan Earthquake and the ratios of extremely high or high hazard grades were more than moderate or low hazard grades obviously.23 geo-hazards after8.13 Big Debris Flow in Qingping town region all occurred in basins with extremely high or high hazard grades,and 9 debris flows were in basins with extremely high hazard grade.The model of multimode system for critical evaluation could forecast not only the collapse and landslide but also the debris flow precisely when the basin was taken as the study unit. 展开更多
关键词 Multimode System Risk assessment Debris flow Landslide Wenchuan Earthquake Qingping Town
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Debris Flows Risk Analysis and Direct Loss Estimation:the Case Study of Valtellina di Tirano,Italy 被引量:5
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作者 Jan BLAHUT Thomas GLADE Simone STERLACCHINI 《Journal of Mountain Science》 SCIE CSCD 2014年第2期288-307,共20页
andslide risk analysis is one of the primary studies providing essential instructions to the subsequent risk management process. The quantification of tangible and intangible potential losses is a critical step becau... andslide risk analysis is one of the primary studies providing essential instructions to the subsequent risk management process. The quantification of tangible and intangible potential losses is a critical step because it provides essential data upon which judgments can be made and policy can be formulated. This study aims at quantifying direct economic losses from debris flows at a medium scale in the study area in Italian Central Alps. Available hazard maps were the main inputs of this study. These maps were overlaid with information concerning elements at risk and their economic value. Then, a combination of both market and construction values was used to obtain estimates of future economic losses. As a result, two direct economic risk maps were prepared together with risk curves, useful to summarize expected monetary damage against the respective hazard probability. Afterwards, a qualitative risk map derived using a risk matrix officially provided by the set of laws issued by the regional government, was prepared. The results delimit areas of high economic as well as strategic importance which might be affected by debris flows in the future. Aside from limitations and inaccuracies inherently included in risk analysis process, identification of high risk areas allows local authorities to focus their attention on the “hot-spots”, where important consequences may arise and local (large) scale analysis needs to be performed with more precise cost-effectiveness ratio. The risk maps can be also used by the local authorities to increase population’s adaptive capacity in the disaster prevention process. 展开更多
关键词 Debris flows Risk analysis Economic losses Central Alps ITALY
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基于FScom集的多层次模糊综合评判法及其应用研究
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作者 李志方 李志梅 +1 位作者 刘丹 杨磊 《兴义民族师范学院学报》 2021年第3期120-124,共5页
FScom集为处理不同的否定提供了集合基础。研究以FScom集为基础的多层次模糊综合评判方法,给出一种基于此方法的泥石流风险等级评估体系,并在实例中进行讨论,将所得的评价结果与传统模糊综合评价法的结果进行对比分析。
关键词 FScom集 多层次模糊综合评判 泥石流风险评估
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Dynamic characteristics and hazard assessment of debris flow in Shangyao valley
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作者 ZHANG Haoran YANG Zhishuang HAN Yulong 《Global Geology》 2012年第2期126-129,共4页
Shangyao valley is located in Jin'an village of Songpan in Sichuan. Many material sources are accumulated in valleys. The debris flow will be triggered by a rain storm with short-duration and strong intensity, whi... Shangyao valley is located in Jin'an village of Songpan in Sichuan. Many material sources are accumulated in valleys. The debris flow will be triggered by a rain storm with short-duration and strong intensity, which may threaten people's lives and property in downstream. Based on the investigation,the formation conditions of debris flow and its dynamic characteristics are analyzed and its hazard assessment is investigated. Research shows that there is the potential cause of debris flow in Shangyao valley,which is of the middle risk class. 展开更多
关键词 debris flow dynamic characteristics hazard assessment Shangyao valley SICHUAN
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Risk assessments of debris flow based on improved analytic hierarchy process and efficacy coefficient method 被引量:2
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作者 LIU Guochao LI Guangjie YANG Lina 《Global Geology》 2012年第3期231-236,共6页
In order to evaluate the danger of debris flow properly, eight factors were selected as the risk assess- ment indexes of the debris flow, namely the vertical slope, valley relative difference, hillside slope, area of ... In order to evaluate the danger of debris flow properly, eight factors were selected as the risk assess- ment indexes of the debris flow, namely the vertical slope, valley relative difference, hillside slope, area of ba- sin, loose solid material reserves, the path length of sediment supply probability, silting and scouring derrieking and vegetation coverage. The improved Analytic Hierarchy Process ( AHP ) method was used to obtain the weights of the factors; and the efficacy coefficient method was adopted to evaluate the risks of six typical debris flow gullies. According to the research, the improved AHP method not only avoids the subjectivity in the indi- vidual factor valuation by comparing two factors of each layer, but also makes the subsequent consistency check unnecessary. 展开更多
关键词 improved AI-IP method efficacy coefficient method debris flow risk assessments
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