Akatani landslide dam

Akatani landslide dam

LCI : JPN169161020
Main Information
Landslide Name : Akatani landslide dam
Latitude : 34:7:25.69 N
Longitude : 135:43:44.81 E
Location
City / District : Yoshino
Province : Nara
Country : Japan
Reporter
Reporter 1 : Pham Tien
Reporter 2 :
Landslide Type
Material : Rock, Debris, Earth
Movement : Slide
Velocity (mm/sec) : Very Rapid
Depth (m) : Deep
Slope (degree) : Steep
Volume (m³) : Very Large
Date of Occurence
Date of Occurence : Sep 04, 2011
Other Information
Land Use Source area : Forest
Run-out/deposition area : Forest, River
Other Activity : Active in the past
Triggering Factor : Rainfall
Death(s) & Missing : -
Houses and other structural damage : -
Photo of landslide :
Google earth kmz file : Akatani landslide dam.kmz
Plan of landslide :
Cross section of landslide :
Reference (paper/report) : SABO (2013) A Pamphlet released in October, 2013 on overview of the 2011 disaster induced by Typhoon No. 12, Implementation of an urgent investigation and countermeasures to disaster areas. Kii Mountain District SABO Office, Kinki Regional Development Bureau. The Ministry of Land, Infrastructure, Transport and Tourism (MLIT). Available at http://www.kkr.mlit.go.jp/kiisanchi/outline/, 24 pages (in Japanese).
Testing graph :
Monitoring graph : -
Video of moving landslides including 3D simulation : -
Description :

The Akatani landslide dam is the second largest landslide dam in Kii Peninsula, which triggered by heavy rainfall in Typhoon Talas on 4 September 2011. The dimensions of the Akatani landslide are about 1,100 m in length, 300 m to 500 m in width and over 65 m in a maximum depth. The impoundment capacity of Akatani dam is up to 9.5 million cubic meters in a large catchment of 13.2 square kilometers. The geology of the Akatani slopes mainly composes materials of mudstone and sandstone, and a part of tuffaceous shale on the head scarp in Miyama Accretionary Complex, Hidakagawa Group of the Cretaceous Shimanto Belt. The Akatani area was suffered from debris flows and erosion disasters in rainstorm seasons after the 2011 disasters. In order to prevent damages from potential risks of dam breach, debris flow and erosions in the future, structural countermeasures have been implementing in a wide area by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT), such as building a system of checking dams and stabilizing the dam.