Slope Failures and Debris Flow Caused by 2018 July Heavy Rain along Katsuradani, Hida City, Gifu Prefecture, Japan

2021 ◽  
Vol 62 (2) ◽  
pp. 92-103
Author(s):  
Takuya JINUSHI ◽  
Hidehisa NAGATA ◽  
Yasuhisa HINO ◽  
Osamu FUSHIKI ◽  
Nobuyuki IKAWA ◽  
...  
Keyword(s):  
Debris Flow ◽  
Heavy Rain ◽  
Slope Failures ◽  
Gifu Prefecture

scholarly journals Propagation Characteristics of Debris Flows Considering Entrainment Effect

2018 ◽  
Vol 7 (3.34) ◽  
pp. 122
Author(s):  
Seokil Jeong ◽  
Junseon Lee ◽  
Chang Geun Song ◽  
Seung Oh Lee
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Flow Behavior ◽  
Prediction Method ◽  
Heavy Rain ◽  
Accurate Analysis ◽  
Propagation Length ◽  
2D Simulation ◽  
Entrainment Effect ◽  
The Relationship

Background/Objectives: Due to the extreme climate and the localized heavy rain, the frequency of debris flow has been increasing. Therefore, there is a growing expectation for accurate numerical analysis.Methods/Statistical analysis: We present a prediction method that can calculate the propagation length of the debris flow. This analysis indicates the relationship between the potential energy and the propagation length of the debris flow. To study the behavior of the debris flow accurately, the change in the momentum force must be considered; otherwise the calculation accuracy of the debris flow behavior is inevitably low.Findings: Entrainment is a common behavior in a debris flow that leads to changes in the momentum force. Here, we analyzed the change in the momentum force using a 2D simulation model that included entrainment. The results show how the debris flow behaves with changes in the momentum force. When entrainment is considered, the propagation length tends to be underestimated. With detailed information, the uncertainty in the prediction accuracy can be reduced.Improvements/Applications: If studies on the material properties of debris flow would be added, it will be possible to carry out various and accurate analysis of the debris flow  

scholarly journals Debris Flow Rule Based on Rough Set Theory Extraction from Disaster Caused by the Nagasaki Heavy Rain in July, 1982.

2002 ◽  
pp. 13-25
Author(s):  
Takeharu SATO ◽  
Yasunori KAWANO ◽  
Yoshinori ARAKI ◽  
Hirotaka NAKAYAMA ◽  
Takahisa MIZUYAMA ◽  
...  
Keyword(s):  
Debris Flow ◽  
Set Theory ◽  
Rough Set ◽  
Rough Set Theory ◽  
Heavy Rain ◽  
Flow Rule ◽  
Rule Based

Unusual disturbance: forest change following a catastrophic debris flow in the Canadian Rocky Mountains

2006 ◽  
Vol 36 (9) ◽  
pp. 2204-2215 ◽  
Author(s):  
Stewart B Rood
Keyword(s):  
Debris Flow ◽  
Populus Tremuloides ◽  
Rocky Mountains ◽  
Forest Type ◽  
Populus Trichocarpa ◽  
Heavy Rain ◽  
Extreme Weather Events ◽  
Canadian Rocky Mountains ◽  
Forest Change ◽  
Riparian Tree

Trees are often well adapted to periodic physical disturbances such as fires or floods. However, I investigated forest response to an extremely unusual disturbance event. Following heavy rain in June 1995 a catastrophic debris flow from Vimy Peak in the Canadian Rocky Mountains terminated as an alluvial debris fan that plowed through a trembling aspen (Populus tremuloides Michx.) grove. I analyzed the site over a decade to monitor forest response and determine whether there would be recolonization to the prior forest type. In contrast to my expectation, aspen recolonization did not occur; instead, black cottonwoods (Populus trichocarpa Torr. & Gray) colonized the site. These originated from seedlings and not through clonal propagation, and by 2004, black cottonwoods composed 99% of the saplings and were typically 0.6–1.4 m tall with a density of about 1/m2. The debris fan dramatically changed the physical environment, which partly resembled a floodplain depositional zone and was colonized by the regionally dominant riparian tree. I propose the concept of foreign disturbance to recognize an unusual disturbance that an organism would very rarely experience and thus to which it is unlikely to be adapted. In this example the disturbance produced an abrupt transition to an alternative forest type and this response may provide insight into forest response to other unusual disturbances, such as extreme weather events, that might increase with climate change.

scholarly journals Some Geomorphological Characteristics of the Slope Failures caused by Heavy Rain Storm in the Southern Part of Thailand in 1988.

Landslides ◽  
1991 ◽  
Vol 28 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Hiroshi OHKURA ◽  
Kouhei TANAKA ◽  
Takahiko FURUYA
Keyword(s):  
Heavy Rain ◽  
Slope Failures

Landslide Disasters in Gifu Prefecture Induced by the Heavy Rain in July, 2018

2021 ◽  
Vol 62 (2) ◽  
pp. 82-91
Author(s):  
Hidehisa NAGATA ◽  
Setsuo HAYASHI ◽  
Shigeyuki SHINODA ◽  
Yukiyasu FUJII ◽  
Osamu FUSHIKI ◽  
...  
Keyword(s):  
Heavy Rain ◽  
Gifu Prefecture

Disaster prevention education through learning about past heavy rainfall and debris flow damage

2020 ◽  
Author(s):  
Banshoya Shogo
Keyword(s):  
High School Students ◽  
Debris Flow ◽  
Heavy Rainfall ◽  
Heavy Rain ◽  
Aerial Photographs ◽  
Disaster Prevention ◽  
School Students ◽  
Prevention Education ◽  
The Past

<p>This study is an introduction to disaster prevention education for high school students, which aims to raise disaster prevention awareness by learning about disasters that occurred in the past. We live in Hiroshima, Japan. There are many fan-shaped regions in this area, and when heavy rain falls due to the rainy season or typhoons, it is easy for debris flow disasters to occur. The most recent damage was caused by a heavy rain in July 2018. On July 7, 2018, 250 to 300 mm of rain fell in one day. As a result, debris flow damage occurred, greatly affecting the students’ life. Debris flow damage is said to occur repeatedly in the same place. Therefore, I think that learning from the past damage will help students learn about future disaster prevention. </p><p>My students have studied the following 1 and 2 since April 2019. And we worked with graduate student and a professor at Hiroshima University.</p><p>1: Case study of debris flow damage caused by a typhoon (Makurazaki-typhoon) that occurred in 1945.</p><p>A huge typhoon occurred in September 1945, causing heavy rainfall and a debris flow disaster. Then our area was very confused. (Because, just after the war, only one month had passed since the atomic bomb was dropped). Therefore, details of the debris flow damage caused by the typhoon are not known.</p><p>So, we analyzed the aerial photographs taken after the disaster and clarified the extent of the damage. We examined the Kirikushi district in Etajima City, Hiroshima Prefecture, Japan as a case area.</p><p> </p><p>2: Case study of debris flow damage through fieldwork.</p><p>We went to the area we studied in 1. We talked with people who were once affected by debris flow damage in 1945.<span>  </span>As a result, we were able to clarify the situation immediately after the occurrence of debris flow.<span>  </span>And we also asked about the debris flow damage in 2018 and compared the two damages.</p>

scholarly journals Slope failures and debris flow characteristics during the 1984 Naganoken-Seibu Earthquake.

1986 ◽  
Vol 27 (3) ◽  
pp. 128-140 ◽  
Author(s):  
Shigeyasu OKUSA ◽  
So ANMA ◽  
Hiromu MAIKUMA ◽  
Yukinori FUJITA ◽  
Yoshimasa MOMIKURA
Keyword(s):  
Debris Flow ◽  
Flow Characteristics ◽  
Slope Failures

scholarly journals ANALYSIS OF DEBRIS FLOW DISASTER DUE TO HEAVY RAIN BY X-BAND MP RADAR DATA

2016 ◽  
Vol XLI-B8 ◽  
pp. 125-132 ◽  
Author(s):  
M. Nishio ◽  
M. Mori
Keyword(s):  
Debris Flow ◽  
Meteorological Data ◽  
Mesh Size ◽  
Heavy Rain ◽  
Japan Meteorological Agency ◽  
Disaster Prevention ◽  
X Band ◽  
Accumulated Rainfall ◽  
Debris Flow Disaster ◽  
Hiroshima City

On August 20 of 2014, Hiroshima City (Japan) was struck by local heavy rain from an autumnal rain front. The resultant debris flow disaster claimed 75 victims and destroyed many buildings. From 1:30 am to 4:30 am on August 20, the accumulated rainfall in Hiroshima City exceeded 200 mm. Serious damage occurred in the Asakita and Asaminami wards of Hiroshima City. As a disaster prevention measure, local heavy rain (localized torrential rains) is usually observed by the Automated Meteorological Data Acquisition System (AMeDAS) operated by the Japan Meteorological Agency (JMA) and by the C-band radar operated by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) of Japan, with spatial resolutions of 2.5 km and 1 km, respectively. The new X-band MP radar system enables more detailed rainfall observations than the C-band radar. In fact, this radar can observe local rainfall throughout Japan in near-real time over a minimum mesh size of 250 m. A fine-scale accumulated rainfall monitoring system is crucial for disaster prevention, and potential disasters can be alerted by the hazard levels of the accumulated rainfall.

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