Abstract
On 4 July 2013, three catastrophic debris flows occurred in the Hougou, Majingzi, and Xiongjia gullies in Shimian county and produced debris dams and river blockages, resulting in serious casualties and huge economic loss. Though debris flows have been identified prior to the catastrophic events, their magnitudes and destructive power were far beyond early recognition and hazard assessment. Our primary objective for this study was to explore the formation mechanism and typical characteristics and to summarize the lessons learned from these disastrous events in order to avoid the repeat of such disasters in the future. Based on field investigation and imagery interpretation of remote sensing carried out following the catastrophic events, four conclusions were drawn: (1) The catastrophic debris flows were initiated from surface-water runoff, and the triggering factor was attributed to the local intensive rainfall with an hourly intensity of more than 46.7 mm. (2) Entrainment was the most important sediment-supplying method for the debris flow occurrence, and the source materials transported by debris flows from the three gullies were estimated to be about 97 × 104 m3 in volume altogether. (3) As surface-water runoff eroded and entrained hillslope and channel materials persistently, debris flows were characterized by intensive incision at upper or middle reaches and significant magnification effect in flow discharge and volume downstream. Corresponding peak discharge surveyed at the outlets of the Hougou, Majingzi, and Xiongjia gullies was estimated up to 751.0 m3/s, 870.1 m3/s, and 758.7 m3/s, respectively. (4) Debris flows that occurred from the three gullies all belonged to viscous ones and the bulk densities were calculated more than 1.80 g/cm3, indicating a huge carrying capacity and destructive impacting power. In addition, the lessons learned from the catastrophic events were summarized, including recognition and assessment on debris flow hazard and utilization of deposition fan. In this paper, prevention suggestions on debris flow prone valleys with high-vegetation coverage and low occurrence frequency were also put forward. The results of this study contribute to a better understanding on the initiation mechanism, dynamic characteristics, and disaster mitigation of debris flows initiated from intense rainfall and surface-water runoff in mountainous areas.
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References
Berti M, Genevois R, Simoni A (2005) Experimental evidences and numerical modeling of debris flows initiated by channel runoff. Landslides 2:171–182
Caine N (1980) The rainfall intensity-duration control of shallow landslides and debris flows. Geogr Ann 62A:23–27
Cannon S, Gartner J, Wilson R (2008) Storm rainfall conditions for floods and debris flows from recently burned areas in southwestern Colorado and southern California. Geomorphology 96:250–269
Chen H, Dadson S, Chi Y (2006) Recent rainfall-induced landslides and debris flows in northern Taiwan. Geomorphology 77:112–125
Chen J, Lin C, Wang L (2009) Geomorphic characteristics of hillslope and channelized debris flows: a case study in the Shitou area of central Taiwan. J Mt Sci 6:266–273
Fiorillo F, Wilson R (2004) Rainfall induced debris flows in pyroclastic deposits, Campania (Southern Italy). Eng Geol 75:263–289
Godt J, Coe J (2007) Alpine debris flows triggered by a 28 July 1999 thunderstorm in the central Front Range, Colorado. Geomorphology 84:80–97
Guzzetti F, Peruccacci S, Rossi M, Stark C (2008) The rainfall intensity-duration control of shallow landslides and debris flows: an update. Landslides 5:3–17
Hungr O, Evans S, Bovis M et al (2001) A review of the classification of landslides of the flow type. Environ Eng Geosci 7(3):221–238
Hürlimann M, Rickenmann D, Graf C (2003) Field and monitoring data of debris-flow events in the Swiss Alps. Can Geotech J 40:161–175
Jakob M, Friele P (2010) Frequency and magnitude of debris flows on Cheekye River, British Columbia. Geomorphology 114:382–395
Ni H, Ba R, Liu Y (2010a) Relation between rainfall and geological hazards and meteorological warning in Shimian County, Sichuan Province. Bull Solid Water Conserv 30(6):112–118 (in Chinese)
Ni H, Zheng W, Li Z et al (2010b) Recent catastrophic debris flows in Luding county, SW China: geological hazards, rainfall analysis and dynamic characterisitcs[J]. Nat Hazards 55:523–542
Ni HY, Zheng WM, Liu XL et al (2011) Fractal-statistical analysis on grain-size distribution of debris-flow deposits and its geological implications. Landslides 8:253–259
Ni HY, Zheng WM, Tie YB et al (2012) Formation and characteristics of post-earthquake debris flow: a case study from Wenjia-gully in Mianzhu, Sichuan, SW China. Nat Hazards 61:317–335
Pelfini M, Santilli M (2008) Frequency of debris flows and their relation with precipitation: a case study in the Central Alps, Italy. Geomorphology 101:721–730
Schuerch P, Densmore AL, Mcardell BW et al (2006) The influence of landsliding on sediment supply and channel change in a steep mountain catchment. Geomorphology 78:222–235
Sepúlveda S, Rebolledo S, Vargas G (2006) Recent catastrophic debris flows in Chile: geological hazard, climatic relationships and human response. Quat Int 158:23–95
Tang C, Zhu J, Ding J et al (2011a) Catastrophic debris flows triggered by a 4 August 2010 rainfall at the epicenter of the Wenchuan earthquake. Landslides 8(4):485–497
Tang C, Rengers N, Asch T et al (2011b) Triggering conditions and depositional characteristics of a disastrous debris flow event in Zhouqu city, Gansu Province, northwestern China. Nat Hazards Earth Syst Sci 11:2903–2912
Tang C, Yang Y, Su Y et al (2011c) The disastrous 23 July 2009 debris flow in Xiangshui gully, Kangding county, Southwestern China. J Mt Sci 8:131–139
Thomas G, Michael C, Peter S (2000) Applying probability determination to refine landslide-triggering rainfall thresholds using an empirical “Antecedent Daily Rainfall Model”. Pure Appl Geophys 157:1059–1079
Wang S (2005) Characterisitics of large low-frequency debris flow hazards and mitigation strategies. J Mt Sci 2(1):50–58
Zhang B, Zhang S, Zhou W (2006) Investigation and assessment of landslides and debris flows in Sichuan province of China by remote sensing technique. Chin Geogr Sci 16(3):223–228
Zhou B, Li D, Luo D (1991) Prevention guide for debris flow. Science press, Beijing (in Chinese)
Acknowledgments
This research is financially supported by the National Science Foundation of China (Grant No. 41102226) and the Project of China Special Project of Basic Work of Science and Technology (Grant No. 2011FY110100-1). Great thanks are given to Chuan Tang for his suggestion on paper writing and to Lan Cao, Guoshi Deng, Renji Ba, and Yujie Liu for their enthusiastic help in material collecting and fieldwork.
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Ni, H., Zheng, W., Song, Z. et al. Catastrophic debris flows triggered by a 4 July 2013 rainfall in Shimian, SW China: formation mechanism, disaster characteristics and the lessons learned. Landslides 11, 909–921 (2014). https://doi.org/10.1007/s10346-014-0514-9
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DOI: https://doi.org/10.1007/s10346-014-0514-9