The evolution characteristics of bedload transport feature of paroxysm debris flow have been studied by means of both theory analysis and experimental data.The analysis based on the flume experiment data of a sand pil...The evolution characteristics of bedload transport feature of paroxysm debris flow have been studied by means of both theory analysis and experimental data.The analysis based on the flume experiment data of a sand pile model as well as a large amount of field data of debris flow clearly shown that the statistical distribu- tion for the main variable of the sand pile made of non-uniform sand (according the sand pile experiment,φ≥2.55) conform to the negative power law,that means the non-uniform sand syste...展开更多
Based on the viewpoint of stress and strain self-organization criticality of debris flow mass, this paper probes into inter-nonlinear action between different factors in the thixotropic liquefaction system of loose cl...Based on the viewpoint of stress and strain self-organization criticality of debris flow mass, this paper probes into inter-nonlinear action between different factors in the thixotropic liquefaction system of loose clastic soil on slope to make clastic soil in slope develop naturally towards critical stress status, and slope debris flow finally occurs under trigging by rainstorm. Also according to observation and analysis of self-organization criticality of sediment run-off system of viscous debris flow surges in ravines and power relation between magnitude and frequency of debris flows, this paper expounds similarity of the self-organized structure of debris flow mass. The self-organized critical system is a weak chaotic system. Debris flow occurrences can be pre-dicted accordingly by means of observation at certain time scale and analysis of self-organization criticality of magni-tude, frequency and time interval of debris flows.展开更多
Defining a basin under a critical state （or a self-organized criticality） that has the potential to initiate landslides, debris flows, and subsequent sediment disasters, is a key issue for disaster prevention. The L...Defining a basin under a critical state （or a self-organized criticality） that has the potential to initiate landslides, debris flows, and subsequent sediment disasters, is a key issue for disaster prevention. The Lushan Hot Spring area in Nantou County, Taiwan, suffered serious sediment disasters after typhoons Sinlaku and Jangmi in aoo8, and following Typhoon Morakot in 2009. The basin＇s internal slope instability after the typhoons brought rain was examined using the landslide frequency-area distribution. The critical state indices attributed to landslide frequency-area distribution are discussed and the marginally unstable characteristics of the study area indicated. The landslides were interpreted from Spot 5 images before and after disastrous events. The results of the analysis show that the power-law landslide frequency-area curves in the basin for different rainfall-induced events tend to coincide with a single line. The temporal trend of the rainfall- induced landslide frequency-area distribution shows 1If noise and scale invariance. A trend exists for landslide frequency-area distribution in log-log space for larger landslides controlled by the historical maximum accumulated rainfall brought by typhoons. The unstable state of the basin, including landslides, breached dams, and debris flows, are parts of the basin＇s self-organizing processes. The critical state of landslide frequency-area distribution could be estimated by a critical exponent of 1.0. The distribution could be used for future estimation of the potential landslide magnitude for disaster mitigation and to identify the current state of a basin for management.展开更多
基金Supported by the National Natureal Science Foundation of China (5040901240025103)
文摘The evolution characteristics of bedload transport feature of paroxysm debris flow have been studied by means of both theory analysis and experimental data.The analysis based on the flume experiment data of a sand pile model as well as a large amount of field data of debris flow clearly shown that the statistical distribu- tion for the main variable of the sand pile made of non-uniform sand (according the sand pile experiment,φ≥2.55) conform to the negative power law,that means the non-uniform sand syste...
基金supported by the Basic Research Funds for Mountain Hazards-Special Support Domain of the Chinese Academy of Sciences(Grant No.99303)Assistance Project of the National Natural Science Foundation of China(Grant No.40071010).
文摘Based on the viewpoint of stress and strain self-organization criticality of debris flow mass, this paper probes into inter-nonlinear action between different factors in the thixotropic liquefaction system of loose clastic soil on slope to make clastic soil in slope develop naturally towards critical stress status, and slope debris flow finally occurs under trigging by rainstorm. Also according to observation and analysis of self-organization criticality of sediment run-off system of viscous debris flow surges in ravines and power relation between magnitude and frequency of debris flows, this paper expounds similarity of the self-organized structure of debris flow mass. The self-organized critical system is a weak chaotic system. Debris flow occurrences can be pre-dicted accordingly by means of observation at certain time scale and analysis of self-organization criticality of magni-tude, frequency and time interval of debris flows.
基金Financial supports under contract NSC 99-2625-M-415-003-MY3 (Chinese Taipei) are appreciated
文摘Defining a basin under a critical state （or a self-organized criticality） that has the potential to initiate landslides, debris flows, and subsequent sediment disasters, is a key issue for disaster prevention. The Lushan Hot Spring area in Nantou County, Taiwan, suffered serious sediment disasters after typhoons Sinlaku and Jangmi in aoo8, and following Typhoon Morakot in 2009. The basin＇s internal slope instability after the typhoons brought rain was examined using the landslide frequency-area distribution. The critical state indices attributed to landslide frequency-area distribution are discussed and the marginally unstable characteristics of the study area indicated. The landslides were interpreted from Spot 5 images before and after disastrous events. The results of the analysis show that the power-law landslide frequency-area curves in the basin for different rainfall-induced events tend to coincide with a single line. The temporal trend of the rainfall- induced landslide frequency-area distribution shows 1If noise and scale invariance. A trend exists for landslide frequency-area distribution in log-log space for larger landslides controlled by the historical maximum accumulated rainfall brought by typhoons. The unstable state of the basin, including landslides, breached dams, and debris flows, are parts of the basin＇s self-organizing processes. The critical state of landslide frequency-area distribution could be estimated by a critical exponent of 1.0. The distribution could be used for future estimation of the potential landslide magnitude for disaster mitigation and to identify the current state of a basin for management.
