Abstract:

Many endmoraine lakes are distributed in Tibet. Once any of theses lakes outbursts, this region will undergo a huge loss. So studying the outburst mechanism is essential for forecast and assessment of the disaster. In this paper, the endmoraine dam is considered as a natural dam and the outburst of endmoraine lake is researched in terms of hydraulics and soil mechanics. According to field observations and previous researches, our study focuses on the overflow and pipingbreak types of outburst. It is found that the dyke breach in the overflow type usually has the shape of an arc or a trapezoid. From the field observations, we have found a relationship between the height and the open width of the breach. Almost all endmoraine lakes collapse partially. Based on field surveys and sampling analysis, we have determined the possible ways of collapse of the Guangxieco endmoraine lake by infiltration.

Key words:

Key words: Tibet; endmoraine lake; outburst form