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Measuring the internal velocity of debris flows using impact pressure detecting in the flume experiment 总被引:2,自引:0,他引:2
Sergey CHERNOMORETS 《山地科学学报》2011,8(2):109-116
Measuring the internal velocity of debris flows is very important for debris flow dynamics research and designing debris flow control works. However, there is no appropriate method for measuring the internal velocity because of the destructive power of debris flow process. In this paper, we address this problem by using the relationship between velocity and kinetic pressure, as described by surface velocity and surface kinetic pressure data. Kinetic pressure is the difference of impact pressure and static pressure. The former is detected by force sensors installed in the flow direction at the sampling section. Observations show that static pressure can be computed using the formula for static water pressure by simply substituting water density for debris flow density. We describe the relationship between surface velocity and surface kinetic pressure using data from seven laboratory flume experiments. It is consistent with the relationship for single phase flow, which is the measurement principle of the Pitot tube. 相似文献
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Debris flows triggered from non-stationary glacier lake outbursts: the case of the Teztor Lake complex (Northern Tian Shan,Kyrgyzstan) 总被引:1,自引:0,他引:1
Sergey Aleksandrovich Erokhin Vitalii Viktorovich Zaginaev Anna Alexandrovna Meleshko Virginia Ruiz-Villanueva Dmitry Aleksandrovich Petrakov Sergey Semenovich Chernomorets Karina Saidovna Viskhadzhieva Olga Valerjevna Tutubalina Markus Stoffel 《Landslides》2018,15(1):83-98
One of the most far-reaching glacier-related hazards in the Tian Shan Mountains of Kyrgyzstan is glacial lake outburst floods (GLOFs) and related debris flows. An improved understanding of the formation and evolution of glacial lakes and debris flow susceptibility is therefore essential to assess and mitigate potential hazards and risks. Non-stationary glacier lakes may fill periodically and quickly; the potential for them to outburst increases as water volume may change dramatically over very short periods of time. After the outburst or drainage of a lake, the entire process may start again, and thus these non-stationary lakes are of particular importance in the region. In this work, the Teztor lake complex, located in Northern Kyrgyzstan, was selected for the analysis of outburst mechanisms of non-stationary glacial lakes, their formation, as well as the triggering of flows and development of debris flows and floods downstream of the lakes. The different Teztor lakes are filled with water periodically, and according to field observations, they tend to outburst every 9–10 years on average. The most important event in the area dates back to 1953, and another important event occurred on July 31, 2012. Other smaller outbursts have been recorded as well. Our study shows that the recent GLOF in 2012 was caused by a combination of intense precipitation during the days preceding the event and a rapid rise in air temperatures. Analyses of features in the entrainment and depositional zones point to a total debris flow volume of about 200,000 m3, with discharge ranging from 145 to 340 m3 s?1 and flow velocities between 5 and 7 m s?1. Results of this study are key for a better design of sound river corridor planning and for the assessment and mitigation of potential GLOF hazards and risks in the region. 相似文献
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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
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Perov Veniamin Chernomorets Sergey Budarina Olga Savernyuk Elena Leontyeva Tatiana 《Natural Hazards》2017,88(1):199-235
The total area of debris flow territories of the Russian Federation accounts for about 10% of the area of the country. The highest debris flow activity areas located in Kamchatka-Kuril, North Caucasus and Baikal debris flow provinces. The largest debris flow events connected with volcano eruptions. Maximum volume of debris flow deposits per one event reached 500 × 106 m3 (lahar formed during the eruption of Bezymyanny volcano in Kamchatka in 1956). In the mountains of the Greater Caucasus, the maximum volume of transported debris material reached 3 × 106 m3; the largest debris flows here had glacial reasons. In the Baikal debris flow province, the highest debris flow activity located in the ridges of the Baikal rift zone (the East Sayan Mountains, the Khamar-Daban Ridge and the ridges of the Stanovoye Highland). Spatial features of debris flow processes within the territory of Russia are analyzed, and the map of Debris Flow Hazard in Russia is presented. We classified the debris flow hazard areas into 2 zones, 6 regions and 15 provinces. Warm and cold zones are distinguished. The warm zone covers mountainous areas within the southern part of Russia with temperate climate; rain-induced debris flows are predominant there. The cold zone includes mountainous areas with subarctic and arctic climate; they are characterized by a short warm period, the occurrence of permafrost, as well as the predominance of slush flows. Debris flow events are described for each province. We collected a list of remarkable debris flow events with some parameters of their magnitude and impact. Due to climate change, the characteristics of debris flows will change in the future. Availability of maps and information from previous events will allow to analyze the new cases of debris flows. 相似文献
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Kurovskaia V. A. Chernomorets S. S. Krylenko I. N. Vinogradova T. A. Dokukin M. D. Zaporozhchenko E. V. 《Water Resources》2022,49(1):58-68
Water Resources - Three likely scenarios of debris flow development in the valley of the Gerkhozhan-Su river are discussed: (I) the passage of a debris flow comparable with that in 2017; (II) a... 相似文献
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Catastrophic detachment and high-velocity long-runout flow of Kolka Glacier, Caucasus Mountains, Russia in 2002 总被引:1,自引:0,他引:1
Stephen G. Evans Olga V. Tutubalina Valery N. Drobyshev Sergey S. Chernomorets Scott McDougall Dmitry A. Petrakov Oldrich Hungr 《Geomorphology》2009,105(3-4):314-321
In September 2002, a catastrophic geomorphic event occurred in the Caucasus Mountains, southern Russia, in which almost the entire mass of Kolka Glacier detached from its bed, accelerated to a very high velocity (max. 65–80 m/s), and traveled a total distance of 19 km downstream as a glacier-debris flow. Based on the interpretation of satellite imagery obtained only 8.5 h before the event occurred, the analysis of seismograms from nearby seismic stations, and subsequent detailed field observations and measurements, we suggest that this remarkable event was not a response to impulse loading from a rock avalanche in the mountainside above the glacier, or to glacier surging, but due entirely to the static and delayed catastrophic response of the Kolka glacier to ice and debris loading over a period of months prior to the September 20 detachment. We reconstruct the glacier-debris flow using field observations in conjunction with the interpretation of seismographs from nearby seismic stations and successfully simulate the behaviour (runout, velocity, and deposition) of the post-detachment glacier-debris flow using a three-dimensional analytical model. Our demonstration of a standing-start hypothesis in the 2002 Kolka Glacier detachment has substantial implications for glacier hazard assessment and risk management strategies in valleys downstream from unstable debris-covered glaciers in the mountain regions of the world. 相似文献
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