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对美姑河沿线10个小流域山洪灾害对省道公路的危险性进行了评价,得出了山洪高危险性、中危险性和低危险性小流域的分布图件,山洪高危险性和中危险性小流域沟口处的公路路段为汛期高危险路段。利用最新获取的SRTM-DEM数据,基于GIS空间分析技术,提取了美姑河流域及10个子流域的典型地貌参数,综合考虑提取的地貌量化参数与小流域山洪危险性的关系,分级量化了小流域山洪对沟口公路的危险性大小。通过对流域地貌参数的分析,得出流域南北向伸展的狭长外形受区域构造和断层控制,美姑河流域新构造运动活跃,处于侵蚀循环的活跃阶段,与美姑河流域水土流失、泥石流等山地灾害发育的实际情况吻合。 相似文献
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滑坡堰塞湖是山区常见的一种自然灾害, 对其溃决风险与过程的科学认知和合理评估是应急处置的关键。外荷载作用下滑坡堰塞体的力学响应、滑坡堰塞湖渐进破坏机理与溃决洪水预测理论是滑坡堰塞湖风险评估研究领域的关键科学问题。本文围绕滑坡堰塞湖形成后的溃决风险与过程展开综述, 从定性和定量的角度分别对堰塞湖危险性评价方法进行分析总结, 从小尺度、大尺度和超重力场试验技术的角度总结了堰塞湖的溃决机理、溃决过程及其影响因素, 从数学方法的角度对堰塞湖溃决洪水预测中经验公式法、简化和精细化数值模拟方法的进展进行总结评价。然而, 国内外关于滑坡堰塞湖风险评估领域的研究仍处于起步阶段, 空-天-地一体化监测技术、堰塞湖危险性评价中的不确定性问题、堰塞体材料冲蚀特性与溃决机理、堰塞湖溃决洪水精细化模拟等将是未来的重点研究方向。本综述可为堰塞湖防灾减灾和流域水工程风险管理提供有价值的参考。 相似文献
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喜马拉雅山中段波曲流域近期冰湖溃决危险性分析与评估 总被引：4，自引：1，他引：3
西藏聂拉木县波曲流域内分布有大量的冰湖,对2000/2001年度卫星遥感数据遥感解译获取了冰湖的分布及面积;对比1987年的数据发现,经过15 a流域内冰湖数量和面积均发生了巨大的变化.通过野外考察获取了重要冰湖的溢流状态、冰碛堤稳定性、冰川影响等资料,在此基础上使用直接判别法和冰湖溃决危险性指数(Idl)进行了冰湖溃决危险性评价,所有冰湖中有9个处于高度危险状态的,3个处于较高危险的,2个处于稳定状态,其余35个处于相对稳定或趋于衰退状态.冲堆普下游、科亚普下游和主河至科亚普汇口以下为高度危险区,塔吉岭普下游、如甲普下游和章藏布下游处于较高危险,其他支沟下游及所有上游区处于冰湖溃决相对安全区.基于危险性评价结果,建议下游根据危险性大小,采取相应的应对措施以减轻冰湖溃决泥石流的危害. 相似文献
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冕宁县安宁河流域为地质灾害密集分布区,安宁河断裂穿越于此,构造复杂,冷渍沟在上游左岸发育。在强降雨条件下,该沟就会暴发泥石流,堵塞安宁河流域和掩埋杀叶马村房屋和道路。冷渍沟泥石流具有流域面积小,主沟长度短,沟床纵比降大等特征,为了研究安宁河流域内泥石流的危险性,以冷渍沟为例,分析不同降雨周期下的泥石流暴发强度,模拟泥石流的运动过程并进行危险性评价。模拟的最大流速、最大堆积深度和降雨强度三者结合建立冷渍沟泥石流危险性评价模型。研究结果表明,冷渍沟泥石流危险范围内高危险区域占27%,主要集中在松散固体物质较多的沟道,中危险性区域和低危险区域各占56%和17%,该结论为危险范围内的居民和重点设施的风险管控提供参考。 相似文献
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刘希林 《中国地质灾害与防治学报》2013,24(2):8-15
针对我国试行的《地质灾害危险性评估技术要求(试行)》存在的问题,认为地质灾害危险性评估应该包括区域评估、流域评估和场地评估三个层次.阐述和分析了顶层设计与区域评估、流域评估和场地评估的任务和内容,对地质灾害危险性评估范围、评估分级、调查内容(以泥石流为例)、评估内容、提交成果,以及评估报告参考提纲等,提出了具体修订建议. 相似文献
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危险性评价是滑坡灾害预防与减灾工作首要解决的重要内容.在地理信息系统技术支持下, 以山地灾害频发区——小江流域作为研究对象, 选取坡度、土体粘聚力和内摩擦角这3个评价指标构建滑坡危险性分级评价指标体系, 将投影寻踪技术运用到滑坡危险性等级评价中, 对评价样本的各指标因素进行线性投影, 以最优投影方向所对应的投影特征值作为评价依据, 建立了滑坡危险性等级综合评价模型, 绘制了滑坡危险性等级分布图.结果表明: 研究区极高危险区、高危险区、中等危险区、低危险区和极低危险区的面积比例为14.28∶9.41∶69.12∶7.00∶0.19;根据所建立的5级评价指标体系对研究区60个土质滑坡点资料进行了验证, 在占研究区总面积23.69%的高、极高危险区的小范围内, 实际发生土质滑坡数量45个, 占总土质滑坡数量的75.00%;中等危险性级别以上区域拥有的土质滑坡数量占全部土质滑坡的96.67%;不同危险性级别的滑坡体积方量统计结果表明, 滑坡体积方量密度随危险性级别的提高而迅速增加.对比评价结果及实测结果可知, 投影寻踪分级结果符合实际情况, 证实了该方法的正确性, 为滑坡危险性评价提供了一条新思路. 相似文献
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陕西陇县地质灾害危险性分区评价 总被引：6，自引：2，他引：6
在陇县地质灾害详细调查的基础上.通过统计分析确定了各类主要影响因素,采用信息量法和定性评价方法分别进行了地质灾害的危险性评价.建立了地质灾害评价指标体系,确定了地质灾害危险性判别标准,进行了地质灾害危险区划.共划分为高危险区、中危险区、低危险区和极低危险区4个等级,在此基础上,又划分了12个亚区.其中高危险区面积为619.19 km2,占总面积的25.79%,中危险区面积为509.74km2,占总面积的21.23%,低危险区面积为711.75 km2,占总面积的29.65%,极低危险区面积为559.87 km2,占全区面积的23.32%. 相似文献
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展布于青藏高原东南部的雅鲁藏布江流域河谷中广泛分布有古堰塞湖沉积,古堰塞湖发育与构造活动、气候变化和地表过程等因素关系密切。在广泛地质调查的基础上,识别出雅鲁藏布江流域的十余个古堰塞湖,通过对其开展沉积学、地貌学和年代学工作,结合前人工作结果,初步建立了古堰塞湖群的地层年代框架。地表残留的古堰塞湖沉积多集中于末次冰期冰盛期和全新世早期,持续时间可达千年—万年。对大竹卡古湖、格嘎古湖和易贡湖的研究结果进行了介绍,归纳出古堰塞湖群发育的基本特征,初步讨论了构造、气候和侵蚀相互作用下古堰塞湖研究的意义、存在的问题以及研究的方向。提出末次冰期以来的冰川(泥石流)堵江-堰塞-溃决洪水所构建的极端气候-灾害事件,对雅鲁藏布江河谷地貌和古地理环境等有重要影响。 相似文献
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流域暴雨山洪过程时空异质性强,准确评估雨洪变化特性和洪水危险性对山洪灾害防治具有重要意义。以7个降雨特征指标和6个洪水特征指标刻画流域场次雨洪特性,采用中国山洪水文模型和洪水频率指标相结合,模拟和评估口前流域洪水过程及其危险性。结果表明：场次洪水洪峰模数、洪峰时间偏度、高脉冲历时占比、涨落洪速率与降雨总量、平均雨量、最大雨强、雨峰位置系数、基尼系数等降雨特征指标显著相关,三场致灾洪水过程的降雨均呈现量级大、强度大、历时短、暴雨中心偏中下游的特点;率定期和验证期的平均径流深相对误差均在9%以内,平均洪峰流量相对误差均在11%以内,平均峰现时间误差均在1.7 h以内,平均Nash-Sutcliffe系数为0.80和0.76;各场次洪水有0.0%～93.3%的河段流量达到一般危险及以上等级,三场致灾洪水过程的危险性等级最高,分别有80.0%、35.0%和1.7%的小流域河段流量达到高危险及以上等级。研究可为山区小流域暴雨洪水危险性评估、灾害响应和复盘等提供技术支撑。 相似文献
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The 12 May Wenchuan earthquake-induced landslide lakes: distribution and preliminary risk evaluation 总被引：26，自引：9，他引：17
The Wenchuan earthquake, measured at M
s 8.0 according to the China Earthquake Administration, occurred at 14:28 on 12 May 2008 in the Sichuan Province of China.
It brought overwhelming destruction to eight provinces and cities. Landslides and rock avalanches triggered by the earthquake
produced 257 landslide lakes which were distributed along the fault rupture zone and river channels. The authors traveled
to the disaster zone immediately after the earthquake to examine some of the features of the debris dams and performed a quick
evaluation of the potential for outburst of earthquake-induced landslide lakes for the purpose of disaster relief. The preliminary
analysis indicated that the landslide lakes could be classified as those exhibiting extremely high risk, medium risk, and
low risk according to field observations and remote sensing, to determine material composition, dam structure, dam height,
maximum water storage capacity, and size of the population potentially affected area. The failure risk of 21 debris dams were
evaluated as follows: one dam with an extremely high danger risk, seven dams with a high danger, five dams with a medium danger,
and eight dams of low danger. More concern was given to the Tangjiashan Lake and different scenarios for the potential sudden
failure of its dam were assessed. The risk evaluation result was accepted in full, by the earthquake disaster relief office.
A successful emergency dam treatment for risk reduction was planned, based on our assessments, and these measures were quickly
carried out. According to this research, the earthquake destabilized the surrounding mountains, resulting in a prolonged geohazard
for the area. Landslides and debris flows will continue to develop for at least 5 to 10 years after the Wenchuan earthquake
and will produce additional dammed lakes. Recommendations and plans for earthquake–landslide lake mitigation were proposed,
based on past successful practices. 相似文献
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Jia-Jyun Dong Yu-Hsiang Tung Chien-Chih Chen Jyh-Jong Liao Yii-Wen Pan 《Engineering Geology》2011,117(1-2):52-61
Landslides may obstruct river flow and result in landslide dams; they occur in many regions of the world. The formation and disappearance of natural lakes involve a complex earth–surface process. According to the lessons learned from many historical cases, landslide dams usually break down rapidly soon after the formation of the lake. Regarding hazard mitigation, prompt evaluation of the stability of the landslide dam is crucial. Based on a Japanese dataset, this study utilized the logistic regression method and the jack-knife technique to identify the important geomorphic variables, including peak flow (or catchment area), dam height, width and length in sequence, affecting the stability of landslide dams. The resulting high overall prediction power demonstrates the robustness of the proposed logistic regression models. Accordingly, the failure probability of a landslide dam can also be evaluated based on this approach. Ten landslide dams (formed after the 1999 Chi-Chi Earthquake, the 2008 Wenchuan Earthquake and 2009 Typhoon Morakot) with complete dam geometry records were adopted as examples of evaluating the failure probability. The stable Tsao-Ling landslide dam, which was induced by the Chi-Chi earthquake, has a failure probability of 27.68% using a model incorporating the catchment area and dam geometry. On the contrary, the Tangjiashan landslide dam, which was artificially breached soon after its formation during the Wenchuan earthquake, has a failure probability as high as 99.54%. Typhoon Morakot induced the Siaolin landslide dam, which was breached within one hour after its formation and has a failure probability of 71.09%. Notably, the failure probability of the earthquake induced cases is reduced if the catchment area in the prediction model is replaced by the peak flow of the dammed stream for these cases. In contrast, the predicted failure probability of the heavy rainfall-induced case increases if the high flow rate of the dammed stream is incorporated into the prediction model. Consequently, it is suggested that the prediction model using the peak flow as causative factor should be used to evaluate the stability of a landslide dam if the peak flow is available. Together with an estimation of the impact of an outburst flood from a landslide-dammed lake, the failure probability of the landslide dam predicted by the proposed logistic regression model could be useful for evaluating the related risk. 相似文献
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区域滑坡灾害预测预警与风险评价 总被引：16，自引：0，他引：16
区域滑坡灾害预测预警是滑坡灾害研究领域的难点和热点。过去10多年来在这方面的研究主要集中在区域降雨与地质环境的结合方面。文章总结了目前国内外滑坡灾害预测预报、预警和风险管理研究现状,认为把滑坡灾害预警预报与风险管理相结合是减灾防灾的需要,也是今后该领域研究的发展趋势。文章从区域滑坡灾害空间预测、时间预警预报的角度提出了滑坡灾害预测预报的分类和理论基础,并在此基础上,利用MapGIS软件平台进行二次开发,建立了基于WebGIS的滑坡灾害信息管理系统和实时预警发布系统。以2004年"云娜"台风期间浙江省永嘉县滑坡灾害预警预报为例,进行了滑坡危险性预测、人口易损性预测、经济易损性预测到风险预测的实例研究。 相似文献
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土石坝抗震安全的设计一般立足于预防结构的倒塌,如何使土石坝结构地震破损控制在可接受的风险水平是一个值得研究的重要课题。应用地震风险分析理论,建立了土石坝地震风险分析方法,包括地震危险性分析、地震易损性分析和地震灾害损失评估3个方面。在场地地震危险性分析基础上,将基于性能的抗震设计思想应用于土石坝结构地震易损性分析中,以土石坝坝顶相对沉陷为评价指标,划分土石坝震损等级,最后结合地震经济损失分析,建立了土石坝地震风险计算模型,在技术和经济上对土石坝地震破损风险进行分析计算。以某高土石坝为例,用该模型对大坝的震害和经济损失进行了预测分析,其结论可为土石坝安全评价及投资决策等提供依据。 相似文献
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The mountain province of East Siberia, which includes the Baikal Rift system, is a zone of high tectonic and seismic hazard. Earthquakes and coseismic faulting are dangerous not only by themselves but also as far as they initiate rock collapse and downslope movement of unconsolidated deposits, which may block river valleys and produce rockfall-dammed lakes. Within some rifts of the rift system, evidence of past dammed lakes was discovered that arose instantly, in a geological sense, and flooded large areas of forest. In mountains around some rift basins, small living dammed lakes were encountered, as well as traces of catastrophic debris flows that may have accompanied breaching of earlier collapse-produced dams. Analysis of geomorphological setting in the region, especially in the Muya Rift Basin, revealed conditions favourable to hazardous origination of rockfall-dammed lakes. A large dammed lake may come into existence due to the collapse of bedrock over the narrow antecedent valley of Vitim in the Muya Rift. Preliminary estimates based upon data on the Vitim River discharge showed that the lake might form in as short as 27 days, though the rapidity of its formation, and hence the degree of the risk, can vary as a function of the highly variable amount of summer discharge of the river. Rockfall-dammed lakes may also originate in the floors of Chara and Tunka Rift Basins. Due to their rapid formation, lakes will bring about extensive flooding and cause danger to the taiga, railways and constructions in this populated developing area, and will cause degradation of the permafrost. 相似文献
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以雅砻江卡拉水电站为例,针对滑坡群风险在水电工程坝址比选时的量化评价问题,在考虑滑坡体危险性分析和易损性分析的基础上,引入滑坡体工程影响系数、重要性系数、距离模数、滑坡体状况系数4个指标参数,综合考虑滑坡体客观情况与人类活动的影响,建立以年期望损失为指标的水电工程滑坡风险评价体系。在以坝址安全风险指标、堵江引起发电量损失指标与清淤损失指标和涌浪破坏损失指标为标准的综合评价方法中,运用安全与经济相平衡原则,得出基于滑坡风险评价的坝址比选结果。经实例计算,采用改进后的评价方法可得同一量纲下的计算分析比常规方法更具可比性,综合考虑可为坝址比选提供依据。 相似文献
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探讨了城市泥石流风险评价的系统方法,该方法包括泥石流扇形地危险区划、城市易损性分析和城市泥石流风险评价三个主要内容。泥石流堆积扇危险区划是基于数值模拟计算出的泥深和流速分布图进行叠合完成的。以美国高分辨率的“快鸟”卫星影像为数据源,完成了研究区的城市土地覆盖类型遥感解译,在此基础上完成了城市泥石流易损性分析,应用地理信息系统提供的统计和分析工具,完成了研究区泥石流风险评价。该风险区划图可用于指导对泥石流易泛区的不同风险地带的土地利用进行规划和决策,从而达到规避和减轻灾害的目的,也为生活在泥石流危险区的城市居民提供有关灾害风险信息,以作避难和灾害防治的依据。 相似文献
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塌岸灾害风险与塌岸灾害特点及人类社会经济活动密切相关,其风险评价涉及诸多因素.将信息量法应用于塌岸灾害风险预测库,建立了相关的信息量模型及评价指标;以重庆万州区和平广场地段为例,在三峡水库蓄水条件下,分别对塌岸灾害的危险性、易损性、风险性进行了综合预测研究.研究结果表明,塌岸评价指标选取合理,塌岸高危险性的单元与不良地质现象、库岸侵蚀和库岸类型密切相关;塌岸灾害易损性与人类社会经济活动及不良地质现象相关;塌岸高风险区主要集中在塌岸高危险性及高易损性单元,或受人口、建筑物分布影响的塌岸中等危险性的单元. 相似文献