The Wenchuan earthquake, measured at Ms 8.0 according to the China Earthquake Administration, occurred at 14:28 on 12 May 2008 in the Sichuan Province of China. It brought overwhelming destruction to eight provinces and cities. Landslides and rock avalanches triggered by the earthquake produced 257 landslide lakes which were distributed along the fault rupture zone and river channels. The authors traveled to the disaster zone immediately after the earthquake to examine some of the features of the debris dams and performed a quick evaluation of the potential for outburst of earthquake-induced landslide lakes for the purpose of disaster relief. The preliminary analysis indicated that the landslide lakes could be classified as those exhibiting extremely high risk, medium risk, and low risk according to field observations and remote sensing, to determine material composition, dam structure, dam height, maximum water storage capacity, and size of the population potentially affected area. The failure risk of 21 debris dams were evaluated as follows: one dam with an extremely high danger risk, seven dams with a high danger, five dams with a medium danger, and eight dams of low danger. More concern was given to the Tangjiashan Lake and different scenarios for the potential sudden failure of its dam were assessed. The risk evaluation result was accepted in full, by the earthquake disaster relief office. A successful emergency dam treatment for risk reduction was planned, based on our assessments, and these measures were quickly carried out. According to this research, the earthquake destabilized the surrounding mountains, resulting in a prolonged geohazard for the area. Landslides and debris flows will continue to develop for at least 5 to 10 years after the Wenchuan earthquake and will produce additional dammed lakes. Recommendations and plans for earthquake–landslide lake mitigation were proposed, based on past successful practices.
[1]
John E. Costa,et al.
The formation and failure of natural dams
,
1988
.
[2]
John J. Clague,et al.
Formation and failure of natural dams in the Canadian Cordillera
,
1994
.
[3]
I. Owens,et al.
Hydrological Aspects of Alpine and High Mountain Areas
,
1984
.
[4]
Nicola Casagli,et al.
Prediction of the behaviour of landslide dams using a geomorphological dimensionless index
,
2003
.
[5]
D. Kallen.
Landslides at Qingjiang River in the Downstream Area of Shuibuya Dam Site, China
,
2006
.
[6]
K. Hewitt.
Natural dams and outburst floods of the Karakoram Himalaya
,
1982
.
[7]
R. Schuster,et al.
Documented historical landslide dams from around the world
,
1991
.
[8]
Oliver Korup,et al.
Geomorphometric characteristics of New Zealand landslide dams
,
2004
.
[9]
Nicola Casagli,et al.
Determining grain size distribution of the material composing landslide dams in the Northern Apennines: sampling and processing methods
,
2003
.
[10]
Yanjun Shang,et al.
A super-large landslide in Tibet in 2000: background, occurrence, disaster, and origin
,
2003
.
[11]
C. F. Lee,et al.
The 1786 earthquake-triggered landslide dam and subsequent dam-break flood on the Dadu River, southwestern China - Reply: A short reply to discussion by Chanson. © 2005 Elsevier B.V. All rights reserved
,
2005
.