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1.
我国西藏地区冰湖溃决灾害综述 总被引：15，自引：4，他引：11
冰湖溃决是我国西藏地区典型的地质灾害类型之一,具有突发性强、规模大、破坏力强和危害范围广等特点,往往造成下游地区遭受惨重的生命财产损失。冰湖溃决成因特征是形成机制、早期识别和危险性评价等冰湖溃决研究的基础,受客观条件限制,我国西藏冰湖溃决的基础调查工作存在资料分散甚至缺失的局限性。为解决这个难题,通过资料收集、遥感解译和野外调查等技术手段,重新梳理了我国西藏地区的冰湖溃决事件及基本特征,共调查出33个冰湖37次溃决事件,其中2个为冰川阻塞湖（简称冰川湖）,划定了冰湖溃决高发地带的地理分布位置,分析出冰崩/冰滑坡、埋藏冰融化、冰川融水、强降水、泥石流和上游冰湖溃决洪水6种诱发原因,为我国西藏冰湖溃决研究提供基础调查成果和参考依据。 相似文献
2.
藏东南冰湖溃决泥石流灾害及其发展趋势 总被引：9，自引：3，他引：6
冰湖溃决泥石流是高山冰湖溃决洪水引起的突发性泥石流,是一种自然灾害现象.西藏冰湖溃决泥石流集中分布于东南部的雅鲁藏布江、波曲及朋曲流域等.冰湖溃决泥石流常形成灾害链对藏东南社会、经济危害严重.分析了气温和降水对冰湖溃决和及其所形成的泥石流的影响,认为冰湖的溃决大部分是由于异常气候条件造成的,冷湿的气候有利于冰川的积累,当气候转为湿热和干热或气温突然升高0.6～1.2 ℃时最易引起冰湖溃决泥石流.通过对西藏地区气候变化的研究,对未来50 a藏东南冰湖溃决泥石流的发展趋势作了预测探讨.一般来讲,气温升高,冰川融水的增加有个临界点,当过了临界点后其冰川融水将会减少,冰湖溃决可能性减少,冰湖溃决泥石流也将减少.也就是说,未来西藏东南部冰湖溃决泥石流的发展趋势,将呈倒"U"字型.冰湖溃决泥石流的发生更多地依赖于突发性的降雨增多. 相似文献
3.
聂拉木县冲堆普2002年泥石流成因分析及防治对策 总被引：7，自引：3，他引：4
聂拉木县冲堆普于2002年5月23日和6月29日先后两次暴发了大规模泥石流灾害,导致下游的水电站、中尼公路、农牧业生产、通讯设施等遭受严重破坏,总共损失约750余万元,给地方社会经济造成了严重的影响.通过对上游的考察和气象资料分析,查清了灾害的形成原因是冲堆普上游冰川融水和嘉龙湖局部溃决所诱发.这是一种多因子共同作用的新型泥石流类型,不同于以往的冰川融水型泥石流和冰湖溃决型泥石流.针对泥石流的危害,提出了防治措施,包括软性措施和硬性措施. 相似文献
4.
冰湖溃决洪水或泥石流（GLOF）是青藏高原主要灾害之一,其形成的灾害链对人民的生命财产安全造成了严重的威胁,其中冰崩导致的冰湖溃决是GLOF的主要灾害形式,但由于其发生位置偏远、间隔时间长、随机性强,导致实地观测资料缺乏,冰崩入湖形成的涌浪机理和过程仍不清晰,而涌浪的规模是GLOF造成下游灾害大小的最主要因素。为分析冰湖涌浪的产生、沿程传播过程和对冰碛坝的爬坡高度,以西藏聂拉木县嘉龙错为例,采用有限体积法,基于流体计算软件Fluent,模拟了嘉龙错补给冰川发生冰崩导致冰湖涌浪的过程。结果表明：数值模拟能较好地对涌浪的产生、规模、沿程传播和对岸爬坡过程进行再现,涌浪初始高度随着冰湖水深、冰体入湖速度和冰体厚度的增加而增大,涌浪高度增加趋势随着冰体入湖速度和冰湖水深的增加而增大,随着冰体厚度的增加而减小。 相似文献
5.
冰湖溃决泥石流是高山冰湖溃决洪水引起的突发性泥石流,是一种自然灾害现象,对藏东南社会、经济危害严重。文中根据实地调查及相关资料,分析了气温和降水对冰湖溃决和冰湖溃决泥石流的影响以及冰湖溃决泥石流年内和年际的形成规律,并认为冰湖的溃决往往是由于异常气候条件造成的,冷湿的气候环境有利于冰川的积累。当气候转为湿热或干热,特别是气候突变异常年代,最易引起冰湖溃决泥石流。受西藏气候变化的影响,未来40年藏东南冰湖溃决泥石流的发展趋势呈抛物线"∩"型。 相似文献
6.
本文分析了主要由冰滑坡和冰崩入湖导致的冰湖溃决的机理和条件.进而,从气候条件、水文条件、终碛堤、冰湖规模、冰滑坡、沟床特征和固体物质补给等方面分析了冰湖溃决泥石流的形成条件和特点,归纳出冰湖溃决泥石流沿程演化的6种模式:溃决洪水-稀性泥石流、溃决洪水-黏性泥石流、溃决洪水-稀性泥石流-黏性泥石流、溃决洪水-黏性泥石流-稀性泥石流、溃决洪水-稀性泥石流-黏性泥石流-稀性泥石流和溃决洪水-黏性泥石流-稀性泥石流-洪水.针对冰湖溃决泥石流突发性强、频度低、洪峰高、流量大、流量过程暴涨暴落、破坏力强和灾害波及范围广等特点,提出了7点减灾对策. 相似文献
7.
入湖冰川受冰湖作用影响,物质损失速率高于其他类型冰川,并导致冰湖进一步扩张,冰湖溃决风险增加。建立入湖冰川物质变化序列,对揭示不同类型冰川对气候变化的响应特征,以及评估冰湖溃决风险研究具有重要意义。基于中国地面气象要素驱动数据集和实测气象数据,采用冰川表面能量-物质平衡模型估算了冰川表面物质变化,并结合冰川流动和末端退缩特征,重建了1989-2018年龙巴萨巴冰川物质变化序列。结果表明,近30a龙巴萨巴冰川总物质损失为0.315km^(3)w.e.,平均物质变化速率为-0.114km^(3)w.e.·a^(-1)。冰川平均表面物质平衡为-0.26m w.e.·a^(-1),表面消融是冰川物质亏损的主要贡献因素。气温变化对冰川表面物质损失的影响高于降水;冰川表面物质平衡对夏季气温和降水变化的敏感性强于其他季节;表碛覆盖加速了冰川表面消融,且较薄的表碛厚度会加剧冰川表面物质损失。 相似文献
8.
亚洲高山区冰湖溃决洪水事件回顾 总被引：3，自引：1，他引：2
冰湖溃决洪水是由冰湖快速大量释水所导致的自然灾害。在全球变暖背景下,亟待建立完整的冰湖溃决洪水数据库,以进一步对冰湖进行危险性评估和风险管理。整理了亚洲高山区（青藏高原及周边地区）的冰湖溃决洪水资料,得出冰湖溃决洪水主要分布在天山山脉、喀喇昆仑山、喜马拉雅山脉、念青唐古拉山、横断山等区域。20世纪以来,亚洲高山区共计发生冰湖溃决洪水277起,其中冰碛湖溃决洪水113起,冰坝湖溃决洪水164起。导致冰碛湖溃决的诱因以冰-雪崩或冰川滑塌为主导,占50.1%,埋藏冰融化或管涌、强降水或上游来水、滑坡-岩崩以及地震占比分别为23.1%、18.5%、7.4%和0.9%。1980年以来,冰碛湖溃决洪水的发生频率呈较弱的增长趋势;但由于发生溃决的冰湖趋于小型化,其溃决水量与洪峰流量在喜马拉雅山脉、天山山脉等地区呈显著下降趋势。2010—2018年间喜马拉雅山脉中段发生8起冰湖溃决洪水事件,远高于天山山脉、喜马拉雅山脉东段和念青唐古拉山等地区,成为新的高发区,是未来重点关注的地区。在未来冰湖溃决洪水频率可能增加的状况下,相关国家和地区在应对冰川灾害、实现区域防灾减灾等方面需要加强沟通交流,共同建立跨区域协调的防灾体系。 相似文献
9.
冰湖溃决泥石流形成的临界条件 总被引：2，自引：0，他引：2
随着全球气候的变暖, 在世界上许多高山峡谷区的冰湖溃决及其溃决洪水引发的泥石流, 经常对下游居民及其他基础设施造成极为严重的危害. 使用水槽试验的方法, 从单宽流量和库容、沟道纵坡、堆积物粒径3个方面探讨了冰湖溃决泥石流形成的影响因素和临界条件. 结果显示: 冰湖溃决泥石流形成与否不仅与溃决洪水提供的能量有关, 还与参与泥石流活动的沟床物质特性紧密相关. 通过对试验数据的分析, 当泥石流形成的特征参数K>2.66时, 冰湖溃决洪水可以演化为泥石流. 该种方法可以对危险性冰湖的预测提供理论参考. 相似文献
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11.
J. Klimeš J. Novotný I. Novotná B. Jordán de Urries V. Vilímek A. Emmer T. Strozzi M. Kusák A. Cochachin Rapre F. Hartvich H. Frey 《Landslides》2016,13(6):1461-1477
Studies focusing on moraine deposits which slide into glacial lakes are scarce, even though they can trigger impact waves responsible for generating glacial lake outburst floods. We focused on landslides in lateral moraines as possible triggers. Detailed geomorphological, geophysical, and satellite radar interferometric investigations of the Palcacocha Lake moraine (Cordillera Blanca, Peru) together with laboratory tests on samples from the site provided data for slope stability calculations using GeoSlope software and hydrodynamic impact wave modeling using the Iber code. We identified landslides that could affect Palcacocha Lake and calculated their stability (factor of safety) under specified conditions, including variable water saturation and earthquake effects. Calculations showed that the moraine slopes are close to the threshold value (Fs?=?1) for stability and are especially sensitive to water saturation. The height of impact waves triggered by a landslide in 2003 and the potential wave heights from newly identified, possibly active landslides were calculated, based on landslide volume estimates, detailed lake bathymetry, and basin topography. Results show that potential future landslide-triggered waves could have similar properties to the 2003 impact wave. Evidence gathered in this study suggests that glacial lake outburst floods triggered by landslides from moraines, however, would be probably smaller than floods resulting from other types of slope processes (e.g., ice/rock avalanches) if dam breach is not taken into account. This assumption has to be critically evaluated against site-specific conditions at a given lake and any possible environmental factors, such as climate change or earthquake that may mobilize larger volumes of moraine material. 相似文献
12.
Glacial hazards in the Rolwaling valley of Nepal and numerical approach to predict potential outburst flood from glacial lake 总被引：3，自引：1，他引：2
Badri Bhakta Shrestha Hajime Nakagawa Kenji Kawaike Yasuyuki Baba Hao Zhang 《Landslides》2013,10(3):299-313
In recent years, climate change and retreating glaciers constitute a major hazard in the Himalaya of South Asia. Glacial lakes are rapidly developing or increasing due to climate change. The rapid development of the lake may cause outburst of the lake. The outburst discharge from the glacial lake can cause catastrophic flooding and disaster in downstream area. Therefore, it is necessary to investigate the impact of climate change on glacial lakes and to understand the characteristics of the glacial lake outburst. In this study, the field assessment of Tsho Rolpa Glacial Lake in the Himalaya of Nepal has been presented and the impact of climate change on this glacial lake has been discussed. The Tsho Rolpa Glacial Lake is the largest and most potentially dangerous glacial lake in Nepal. In addition, a numerical model has been also developed for computing the characteristics of glacial lake outburst due to moraine dam failure by seepage and water overtopping. The numerical model is tested for the flume experimental cases. The simulated results of the outburst discharge, the dam surface erosion, and the temporal variation of the moisture movement in the dam are compared with those obtained from the hydraulic model experiments. The moisture profile calculated by numerical model was agreeable with the experimental moisture profile. The simulated failure surface of the dam due to seepage by considering the suction in slope stability analysis gave more agreeable results than the Janbu's simplified method. The results of the outburst discharge and dam surface erosion also agreed with the experimental results. 相似文献
13.
西藏典型冰湖溃决型泥石流的初步研究 总被引：6，自引：0，他引：6
刘伟 《水文地质工程地质》2006,33(3):88-92
西藏地区冰川面积约为35000km^2,是我国现代冰川分布最多的地区,也是现代冰湖分布最多的地区.在现代冰川前进或跃动、冰舌断裂、冰湖岸坡出现崩塌或滑坡、温度骤然增加导致冰川融化加速、湖口向源侵蚀加剧、坝体下部管涌引起塌陷等诸多可能因素的影响下易造成冰湖溃决,出现洪水、稀性泥石流、粘性泥石流等危害方式,造成的灾害远远大于由降水引发的泥石流灾害,常常形成危害严重的地质灾害链. 相似文献
14.
Gohar Rehman Sajjad Ahmad Shuhab D. Khan Fayaz Ali Taqweemul H. Ali Sadaf F. Khan 《Natural Hazards》2014,70(2):1589-1602
Glacial lake outburst flood (GLOF) is a powerful natural phenomenon that is very active in the Karakoram and Himalayas. This paper presents a case study from Gupis Tehsil in northern areas of Pakistan that is exposed to GLOFs from nine different glacial lakes in its upper catchment areas. Khukush Lake being the largest of all the glacial lakes has been studied and a flood attenuation model has been created for the whole Gupis Tehsil. This lake covers almost 2.2 km2 of surface area, and its calculated volume is 2.6 × 104 m3. In case of its outburst, the peak flow discharge is calculated to be 7,642 m3/s. The catchment area which contributes water and debris to the lake is 170 km2. This lake is dammed by a glacial moraine, which is not strong enough to sustain the pressure for a longer period of time. Other factors that are reducing the reliability of the dam are the secondary hazards which are in direct contact with the lake, and in case of their reactivation, they can put severe impacts on the dam. There are eight potential sites of the snow avalanche activity where debris along with snow may fall directly into the lake producing a strong wave. This strong wave of water will increase the pressure on the dam and ultimately will increase the probability for its outburst. The presense of water springs towards the downstream side of the natural dam also indicate the presence of hidden channels passing through the dam which may weaken the shear strength of the dam. Almost 24 villages settled along either sides of the Gupis River are critically studied for the expected flood from Khukush Lake. With few exceptions, almost 20–25 % area of all the villages will be affected from this flood. 相似文献
15.
Monitoring of Bashkara Glacier lakes (Central Caucasus, Russia) and modelling of their potential outburst 总被引：2，自引：1，他引：1
D. A. Petrakov O. V. Tutubalina A. A. Aleinikov S. S. Chernomorets S. G. Evans V. M. Kidyaeva I. N. Krylenko S. V. Norin M. S. Shakhmina I. B. Seynova 《Natural Hazards》2012,61(3):1293-1316
Glacier lakes pose threat to downstream settlements and infrastructure. In recent decades the number and area of lakes have
been growing at an accelerating rate due to worldwide glacier shrinkage. In the Russian Caucasus this process is understudied.
We present results obtained during a 12-year (1999–2010) continuous field monitoring of the Bashkara proglacial lakes group,
which we identified as the place with the highest GLOF risk in the region. Recession of the parent Bashkara Glacier was the
main driver of the rapid expansion of the lower Lake Lapa. The upper Lake Bashkara has not been enlarging, but its water level
has shown significant inter- and intra-annual fluctuations. The lake outburst probability has increased in recent years, and
in 2008 we observed surface overflow over the moraine dam. Taking into account that in the late 1950s lake outbursts at this
site led to large-scale glacial debris flows, we have simulated a potential outburst using River and FLO-2D software and carried
out hazard zonation. An early warning system has been designed and established at Lake Bashkara, and measures to mitigate
risk have been proposed. Rapid change of proglacial lakes requires regular monitoring in ‘hot spot’ areas where the GLOF hazard
is high and is dynamically changing. 相似文献
16.
汶川八级地震地质灾害研究 总被引：118，自引：15，他引：103
汶川地震触发了15000多处滑坡、崩塌、泥石流,估计直接造成2万人死亡。地质灾害隐患点达10000余多处,以崩塌体增加最为显著,反映出地震对山区高陡斜坡的影响差异性非常大,在山顶上的放大作用非常显著。通过综合分析堰塞湖库容、滑坡坝高以及坝体物质组成和结构,对地震形成的33处坝高大于10m的滑坡堰塞湖进行了评估,划分出极高、高、中和低4种溃决危险。汶川地震滑坡滑床往往不具连续平整的滑面,尖点撞击是极震区滑坡的一大共性,可以分为勺型滑床、凸型滑床和阶型滑床等类型。据实地调查,滑坡附近震毁建筑物垂向震动非常明显,具有地震抛掷撞击崩裂高速滑流三阶段特征。在高速滑流中,发生3种效应:(1)高速气垫效应,滑坡体由较大块石和土构成,具有一定厚度,飞行行程可达1~3km;(2)碎屑流效应,撞击粉碎的土石呈流动状态,特别是含水丰富时,形成长程流滑;(3)铲刮效应,巨大撞击力导致下部岩体崩裂,形成新滑坡、崩塌,但是,其厚度不大,滑床起伏不平。本文以北川城西滑坡和青川东河口滑坡为例,分析了地震滑坡高速远程滑动及成灾机理。北川县城城西滑坡导致1600人被埋死亡,数百间房屋被毁,是汶川地震触发的最严重的滑坡灾难,举世罕见。青川东河口滑坡碎屑流是汶川地震触发的较为典型的高速远程复合型滑坡,滑程约2400m,高速碎屑流冲抵清江河左岸,形成滑坡坝,致使7个村庄被埋,约400人死亡。 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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2020年6月17日丹巴县梅龙沟爆发了一次大规模泥石流,一次性冲出固体物质42.7×104 m3,形成泥石流-堰塞坝-溃决洪水-滑坡灾害链,造成5100余户2.12万余人被迫转移,直接经济损失达8亿元。根据现场调查、无人机航拍以及遥感解译,分析梅龙沟泥石流的成因及致灾机理,阐述了“物源成因”、“降雨激发”和“地形促进”对泥石流形成产生的影响。结果表明:（1）梅龙沟泥石流是在前期累计降雨和短时强降雨共同作用下形成;（2）梅龙沟泥石流源头为大石堡沟,起动模式为“沟岸垮塌-泥石流”;（3）泥石流沟内持续的物源补给以及东风棚子、梅龙村、大邑村三处大型滑坡产生的级联堵溃效应,致使泥石流流量不断放大,最终导致大量固体物质冲出沟口;（4）沟口形成的堰塞坝-溃决洪水-阿娘寨滑坡灾害链进一步增强了泥石流的致灾能力;（5）现阶段梅龙沟内物源丰富,临界启动降雨阈值降低,极易在雨季发生大规模泥石流,建议及时采取综合防治措施。 相似文献