Debris flow is a common natural hazard in the mountain areas of Western China due to favorable natural conditions, and also exacerbated by mountainous exploitation activities. This paper concentrated on the characteri...Debris flow is a common natural hazard in the mountain areas of Western China due to favorable natural conditions, and also exacerbated by mountainous exploitation activities. This paper concentrated on the characteristics, causes and mitigation of a catastrophic mine debris flow hazard at Longda Watershed in Songpan County, Sichuan Province, on 21 July 2011. This debris flow deposited in the front of the No.1 dam, silted the drainage channel for flood and then rushed into tailing sediment reservoir in the main channel and made the No.2 dam breached. The outburst debris flow blocked Fu River, formed dammed lake and generated outburst flood, which delivered heavy metals into the lower reaches of Fu River, polluted the drink water source of the population of over 1 million. The debris flow was characterized with a density of 1.87～2.15 t/m3 and a clay content of less than 1.63%. The peak velocity and flux at Longda Gully was over l0.0～10.9 m/s and 429.o～446.o m3/s, respectively, and the flux was about 700 m3/s in main channel, equaling to the flux of the probability of 1%. About 33o,ooorn3 solid materials was transported by debris flow and deposited in the drainage tunnel （120,000～130,000 m3）, the front of No.1 dam （100,000 m3） and the mouth of the watershed （l00,000～110,000 m3）, respectively. When the peak flux and magnitude of debris flow was more than 462 m3/s and 7,423 m3, respectively, it would block Fu River and produce a hazard chain which was composed of debris flow, dammed lake and outburst flood. Furthermore, the 21 July large-scale debris flow was triggered by rainstorm with an intensity of 21.2 mm/0.5 h and the solid materials of debris flow were provided by landslides, slope deposits, mining wastes and tailing sediments. The property losses were mainly originated from the silting of the drainage tunnel for flash flood but not for debris flow and the irrational location of tailing sediment reservoir. Therefore, the mitigation measures for mine debris flows were presented： （1） The disastrous debris flow watershed should be identified in planning period and prohibited from being taken as the site of mining factories; （2） The mining facilities are constructed at the safe areas or watersheds; （3） Scoria plots, concentrator factory and tailing sediment reservoir are constructed in safe areas where the protection measures be easily made against debris flows; （4） The appropriate system and plan of debris flow mitigation including monitoring, remote monitoring and early-warning and emergency plan is established; （5） The stability of waste dump and tailing sediment reservoir are monitored continuously to prevent mining debris flows.展开更多
People are witnesses of life imperilling and working background too, as today, even during the evolution. People＇s life interface is disturbed with different shapes of contamination： natural disasters （floods, eart...People are witnesses of life imperilling and working background too, as today, even during the evolution. People＇s life interface is disturbed with different shapes of contamination： natural disasters （floods, earthquakes, volcanic eruptions and the other）; on purpose or accidentally-different shapes like： wars, fires, chemical fates, using of dangerous materials in production processes and everyday life... In these mentioned specific conditions, breathing is imperiled, like the vital function of men＇s life and working interfaces. With the technical-technology progress, it is enclosed the development equipment for protection and safety of the respiratory parts of body, faces and eyes, regard to breathing apparatus. Applying the breathing apparatus, the total protection of the respiratory parts of the body, faces and eyes to aggressive materials, smoke and warmth is enabled. Today in the world there are many producers of breathing apparatus with similar technical-technological solutions, of which should be mentioned the main ones： MSA Auer, Dr/iger and Interspiro. Using of the breathing apparatus in practice, continual performation of different activities without consequences for the health and life of the user is enabled, what firstly depends on the user＇s education, regular using, controlling examination and maintenance/servicing.展开更多
基金supported by National Basic Research Program of China (2011CB409902)National Key Technologies R & D Program of China (2012BAK10B04)
文摘Debris flow is a common natural hazard in the mountain areas of Western China due to favorable natural conditions, and also exacerbated by mountainous exploitation activities. This paper concentrated on the characteristics, causes and mitigation of a catastrophic mine debris flow hazard at Longda Watershed in Songpan County, Sichuan Province, on 21 July 2011. This debris flow deposited in the front of the No.1 dam, silted the drainage channel for flood and then rushed into tailing sediment reservoir in the main channel and made the No.2 dam breached. The outburst debris flow blocked Fu River, formed dammed lake and generated outburst flood, which delivered heavy metals into the lower reaches of Fu River, polluted the drink water source of the population of over 1 million. The debris flow was characterized with a density of 1.87～2.15 t/m3 and a clay content of less than 1.63%. The peak velocity and flux at Longda Gully was over l0.0～10.9 m/s and 429.o～446.o m3/s, respectively, and the flux was about 700 m3/s in main channel, equaling to the flux of the probability of 1%. About 33o,ooorn3 solid materials was transported by debris flow and deposited in the drainage tunnel （120,000～130,000 m3）, the front of No.1 dam （100,000 m3） and the mouth of the watershed （l00,000～110,000 m3）, respectively. When the peak flux and magnitude of debris flow was more than 462 m3/s and 7,423 m3, respectively, it would block Fu River and produce a hazard chain which was composed of debris flow, dammed lake and outburst flood. Furthermore, the 21 July large-scale debris flow was triggered by rainstorm with an intensity of 21.2 mm/0.5 h and the solid materials of debris flow were provided by landslides, slope deposits, mining wastes and tailing sediments. The property losses were mainly originated from the silting of the drainage tunnel for flash flood but not for debris flow and the irrational location of tailing sediment reservoir. Therefore, the mitigation measures for mine debris flows were presented： （1） The disastrous debris flow watershed should be identified in planning period and prohibited from being taken as the site of mining factories; （2） The mining facilities are constructed at the safe areas or watersheds; （3） Scoria plots, concentrator factory and tailing sediment reservoir are constructed in safe areas where the protection measures be easily made against debris flows; （4） The appropriate system and plan of debris flow mitigation including monitoring, remote monitoring and early-warning and emergency plan is established; （5） The stability of waste dump and tailing sediment reservoir are monitored continuously to prevent mining debris flows.
文摘People are witnesses of life imperilling and working background too, as today, even during the evolution. People＇s life interface is disturbed with different shapes of contamination： natural disasters （floods, earthquakes, volcanic eruptions and the other）; on purpose or accidentally-different shapes like： wars, fires, chemical fates, using of dangerous materials in production processes and everyday life... In these mentioned specific conditions, breathing is imperiled, like the vital function of men＇s life and working interfaces. With the technical-technology progress, it is enclosed the development equipment for protection and safety of the respiratory parts of body, faces and eyes, regard to breathing apparatus. Applying the breathing apparatus, the total protection of the respiratory parts of the body, faces and eyes to aggressive materials, smoke and warmth is enabled. Today in the world there are many producers of breathing apparatus with similar technical-technological solutions, of which should be mentioned the main ones： MSA Auer, Dr/iger and Interspiro. Using of the breathing apparatus in practice, continual performation of different activities without consequences for the health and life of the user is enabled, what firstly depends on the user＇s education, regular using, controlling examination and maintenance/servicing.
