Safety Assessment of Quake Lakes

The great Wenchuan Earthquake of May 12, 2008 formed more than 100 quake lakes with considerable risks. These Quake lakes are mostly distributed on the mountainous rivers in the worst-hit areas. Some are densely distributed in a segment of river channels; others in remote areas. 90% of the Quake lakes have gone through emergency treatment process or have self-burst, and have weathered through the flood seasons in 2008 and 2009. However, their long-term stability and safety need to be thoroughly evaluated, and some may require proper retrofit to ensure their long-term stability. Retrofit techniques will depend upon the risks imposed to the downstream area, geological conditions, landforms, hydrology, and the size and composition of the landslide dam. By using cases selected from Quake lakes formed by Wenchuan Earthquake, this paper discusses techniques for improved safety assessment of Quake lakes.