scholarly journals Quantitative Prediction of Outburst Flood Hazard of the Zhouqu “8.8” Debris Flow-Barrier Dam in Western China

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 639
Author(s):  
Heyi Yang ◽  
Guan Chen ◽  
Yan Chong ◽  
Jiacheng Jin ◽  
Wei Shi
Keyword(s):  
Water Resources ◽  
Debris Flow ◽  
Flood Hazard ◽  
Peak Discharge ◽  
Western China ◽  
Dam Failure ◽  
Quantitative Prediction ◽  
Outburst Flood ◽  
Dam Breach ◽  
Barrier Dam

In recent years, the intensified influences of global climate change and human activities have increased the frequency of large-scale debris flow disasters. As a result, main river channels often become blocked, thus forming a disaster chain of rivers dammed by debris flow followed by outburst flooding. In order to quickly and easily reveal the dynamic process of a debris flow dam breach, and quantitatively predict the outburst flood hazard, this study takes the Zhouqu “8.8” debris flow barrier dam in Western China as an example. Based on a stability assessment, China Institute of Water Resources and Hydropower Research’s Dam Breach Slope (DBS-IWHR), China Institute of Water Resources and Hydropower Research’s Dam Breach (DB-IWHR), and Hydrologic Engineering Center’s River Analysis System (HEC-RAS) were integrated to simulate the development of dam breach, breach flood, and outburst flood evolution, respectively, under different scenarios. The simulated peak discharge flow of the actual spillway was 317.15 m3/s, which was consistent with the actual discharge of 316 m3/s. The results under different scenarios showed that, with the increased inflow of the barrier lake, the erosion rate of the dam increased, the peak discharge of the dam break flood increased, the peak arrival time shortened, and the downstream flooding area increased. These findings could provide scientific support for risk management and emergency decision-making with respect to barrier dam failure.

Comparison on the failure process and mechanism between a debris flow and a landslide dam

2020 ◽  
Author(s):  
Huayong Chen ◽  
Chunran Cao ◽  
Xiaoqing Chen ◽  
Jiangang Chen
Keyword(s):  
Debris Flow ◽  
Water Content ◽  
Failure Process ◽  
Landslide Dam ◽  
Clay Content ◽  
Peak Discharge ◽  
Initial Water Content ◽  
Dam Breach ◽  
Initial Water ◽  
Landslide Dams

<p>Besides the numerous artificial dams, there are some other kind of dams distribute such as the glacier dams, moraine dams, landslide dams, and the debris flow dams in China. Especially, the landslide dams and debris flow ones widely distribute in southwest of China after the M8.0 Wenchuan earthquake. Much attention has been paid to the formation, stability, breach process, and the peak discharge prediction of a landslide dam. However few achievements are obtained on the debris flow dams even if the failure of a debris flow dam has posed great threat to the property and life of residents downstream. In this paper, based on the main difference between a landslide and debris flow dam, experiments were conducted by considering different clay content, the initial water content, and incoming water flow. It indicated that the failure duration of a debris flow dam was about 1.60 times as long as that than that of a landslide dam. The peak discharge at the debris flow dam breach was 5.38 L/s. However, the peak discharge at the landslide dam was 7.50 L/s, which was 1.39 times as big as that of a debris flow dam. Finally, by modifying the existing critical initialization condition for the landslide dams, the critical initialization condition for a debris flow dam was proposed.</p>

scholarly journals Characteristics of a Debris Flow Disaster and Its Mitigation Countermeasures in Zechawa Gully, Jiuzhaigou Valley, China

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1256 ◽  
Author(s):  
Xing-Long Gong ◽  
Kun-Ting Chen ◽  
Xiao-Qing Chen ◽  
Yong You ◽  
Jian-Gang Chen ◽  
...  
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Peak Discharge ◽  
Dam Failure ◽  
Check Dam ◽  
Jiuzhaigou Earthquake ◽  
Property Losses ◽  
Jiuzhaigou Valley ◽  
Engineering Projects ◽  
Debris Flow Disaster

On 8 August 2017, an Ms 7.0 earthquake struck Jiuzhaigou Valley, triggering abundant landslides and providing a huge source of material for potential debris flows. After the earthquake debris flows were triggered by heavy rainfall, causing traffic disruption and serious property losses. This study aims to describe the debris flow events in Zechawa Gully, calculate the peak discharges of the debris flows, characterize the debris flow disasters, propose mitigation countermeasures to control these disasters and analyse the effectiveness of countermeasures that were implemented in May 2019. The results showed the following: (1) The frequency of the debris flows in Zechawa Gully with small- and medium-scale will increase due to the influence of the Ms 7.0 Jiuzhaigou earthquake. (2) An accurate debris flow peak discharge can be obtained by comparing the calculated results of four different methods. (3) The failure of a check dam in the channel had an amplification effect on the peak discharge, resulting in a destructive debris flow event on 4 August 2016. Due to the disaster risk posed by dam failure, both blocking and deposit stopping measures should be adopted for debris flow mitigation. (4) Optimized engineering countermeasures with blocking and deposit stopping measures were proposed and implemented in May 2019 based on the debris flow disaster characteristics of Zechawa Gully, and the reconstructed engineering projects were effective in controlling a post-earthquake debris flow disaster on 21 June 2019.

Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA

2006 ◽  
Vol 65 (02) ◽  
pp. 324-335 ◽  
Author(s):  
Cassandra R. Fenton ◽  
Robert H. Webb ◽  
Thure E. Cerling
Keyword(s):  
Colorado River ◽  
Grand Canyon ◽  
Peak Discharge ◽  
Dam Failure ◽  
Flow Modeling ◽  
Hydraulic Characteristics ◽  
Outburst Flood ◽  
The Usa ◽  
Order Of Magnitude ◽  
Flood Deposits

AbstractThe failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of the Hyaloclastite Dam released a maximum 11 × 109 m3 of water in 31 h. Peak discharges, estimated from uncertainty in channel geometry, dam height, and hydraulic characteristics, ranged from 2.3 to 5.3 × 105 m3 s−1 for the Hyaloclastite outburst flood. This discharge is an order of magnitude greater than the largest known discharge on the Colorado River (1.4 × 104 m3 s−1) and the largest peak discharge resulting from failure of a constructed dam in the USA (6.5 × 104 m3 s−1). Moreover, the Hyaloclastite outburst flood is the oldest documented Quaternary flood and one of the largest to have occurred in the continental USA. The peak discharge for this flood ranks in the top 30 floods (>105 m3 s−1) known worldwide and in the top ten largest floods in North America.

scholarly journals Brief communication: Observations of a glacier outburst flood from Lhotse Glacier, Everest area, Nepal

2017 ◽  
Vol 11 (1) ◽  
pp. 443-449 ◽  
Author(s):  
David R. Rounce ◽  
Alton C. Byers ◽  
Elizabeth A. Byers ◽  
Daene C. McKinney
Keyword(s):  
Satellite Imagery ◽  
Peak Discharge ◽  
Dam Failure ◽  
Outburst Flood ◽  
Recent Event ◽  
Triggering Mechanism ◽  
Flood Water ◽  
Outburst Floods ◽  
Field Assessment

Abstract. Glacier outburst floods with origins from Lhotse Glacier, located in the Everest region of Nepal, occurred on 25 May 2015 and 12 June 2016. The most recent event was witnessed by investigators, which provided unique insights into the magnitude, source, and triggering mechanism of the flood. The field assessment and satellite imagery analysis following the event revealed that most of the flood water was stored englacially and that the flood was likely triggered by dam failure. The flood's peak discharge was estimated to be 210 m3 s−1.

Reliability Concepts in Reservoir Design

1989 ◽  
Vol 20 (4-5) ◽  
pp. 231-248 ◽  
Author(s):  
Erich J. Plate
Keyword(s):  
Water Resources ◽  
Reliability Analysis ◽  
Conceptual Models ◽  
Dam Failure ◽  
Figures Of Merit ◽  
Irrigation Reservoir ◽  
Modes Of Failure ◽  
Reservoir Design ◽  
General Reliability ◽  
Operational Failure

The case of a dam for an irrigation reservoir is used as an example to illustrate the different modes of failure of a water resources system. The types of failure to which a dam can be subjected are described in the first section of the paper, in terms of a framework of general reliability analysis. Two applications are considered: the case of operational failure, illustrated by means of an irrigation reservoir for arid countries, and the case of dam failure due to overtopping. Conceptual models are given which permit the inclusion of reliability and other figures of merit into both operation and safety analysis.

Extreme mass wasting during 2021 Dhauli Ganga event in the Higher Himalaya: insight from the landscape

2021 ◽  
Author(s):  
Anand Kumar Pandey ◽  
Kotluri Sravan Kumar ◽  
Virendra Mani Tiwari ◽  
Puranchand Rao ◽  
Kirsten Cook ◽  
...  
Keyword(s):  
Debris Flow ◽  
Extreme Event ◽  
Rock Avalanche ◽  
Slope Instability ◽  
Mass Wasting ◽  
Outburst Flood ◽  
Flood Warning ◽  
River Bed ◽  
High Flood ◽  
Glacial Lake Outburst Flood

<p>The slope instability and associated mass wasting are among the most efficient surface gradation processes in the bedrock terrain that produce dramatic landscape change and associated hazards. The wedge failure in periglacial Higher Himalaya terrain on 7th February in Chamoli, Uttarakhand (India) produced >1.5 km high rock avalanche, which amalgamated with the glacial debris on the frozen river bed produced massive debris flow along the high gradient Rishi Ganga catchment. The high-velocity debris flow and a surge of high flood led to extensive loss of life and infrastructures and issuing the extreme event flood warning along the Alakananda-Ganga river, despite there was no immediate extreme climatic event. The affected region is the locus of extreme mass wasting events associated with Glacial Lake Outburst Flood (GLOF) and Landslide Lake Outburst Flood (LLOF) in the recent past. We analyzed the landscape to understand its control on the 7th February 2021 Rishi Ganga event and briefly discuss other significant events in the adjoining region e.g. 1893/1970 Gohna Tal/Lake LLOF and 2013-Uttarakhand events in Chamoli, which have significance in understanding the surface processes in Higher Himalayan terrain.</p>

scholarly journals The 2020 glacial lake outburst flood at Jinwuco, Tibet: causes, impacts, and implications for hazard and risk assessment

2021 ◽  
Author(s):  
Guoxiong Zheng ◽  
Martin Mergili ◽  
Adam Emmer ◽  
Simon Allen ◽  
Anming Bao ◽  
...  
Keyword(s):  
Time Lag ◽  
Peak Discharge ◽  
Glacial Lake ◽  
Lateral Moraine ◽  
Process Chain ◽  
Outburst Flood ◽  
Impact Wave ◽  
Debris Landslide ◽  
Property Losses ◽  
Glacial Lake Outburst Flood

Abstract. We analyze and reconstruct a recent Glacial Lake Outburst Flood (GLOF) process chain on 26 June 2020, involving the moraine-dammed proglacial lake Jinwuco (30.356° N, 93.631° E) in eastern Nyainqentanglha, Tibet, China. Satellite images reveal that from 1965 to 2020, the surface area of Jinwuco has expanded by 0.2 km2 (+56 %) to 0.56 km2, and subsequently decreased to 0.26 km2 (‒54 %) after the GLOF. Estimates based on topographic reconstruction and sets of published empirical relationships indicate that the GLOF had a volume of 10 million m3, an average breach time of 0.62 hours, and an average peak discharge of 5,390 m3/s at the dam. Based on pre- and post-event high-resolution satellite scenes, we identified a large progressive debris landslide originating from western lateral moraine, having occurred 5–17 days before the GLOF. This landslide was most likely triggered by extremely heavy, south Asian monsoon-associated rainfall in June. The time lag between the landslide and the GLOF suggests that pre-weakening of the dam due to landslide-induced outflow pushed the system towards a tipping point, that was finally exceeded following subsequent rainfall, snowmelt, a secondary landslide, or calving of ice into the lake. We back-calculate part of the GLOF process chain, using the GIS-based open source numerical simulation tool r.avaflow. Two scenarios are considered, assuming a debris landslide-induced impact wave with overtopping and resulting retrogressive erosion of the moraine dam (Scenario A), and retrogressive erosion due to pre-weakening of the dam without a major impact wave (Scenario B). Both scenarios yield plausible results which are in line with empirically derived ranges of peak discharge and breach time. The breaching process is characterized by a slower onset and a resulting delay in Scenario B, compared to Scenario A. Evidence, however, points towards Scenario B as a more realistic possibility. There were no casualties from this GLOF but it caused severe destruction of infrastructure (e.g. roads and bridges) and property losses in downstream areas. Given the clear role of continued glacial retreat in destabilizing the adjacent lateral moraine slopes, and directly enabling the landslide to deposit into the expanding lake body, the GLOF process chain under Scenario B can be robustly attributable to anthropogenic climate change, while downstream consequences have been enhanced by the development of infrastructure on exposed flood plains. Such process chains could become more frequent under a warmer and wetter future climate, calling for comprehensive and forward-looking risk reduction planning.

Geomorphic effect of debris-flow sediments on the Min River, Wenchuan Earthquake region, western China

2021 ◽  
Vol 18 (9) ◽  
pp. 2427-2440
Author(s):  
Xu-dong Hu ◽  
Li-qin Zhou ◽  
Wei-ming Liu ◽  
Hao Wang ◽  
Lei Cui
Keyword(s):  
Debris Flow ◽  
Wenchuan Earthquake ◽  
Western China ◽  
Min River
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