The Damming Event in the Yueju Section of the Middle Yarlung Tsangpo River
The middle reaches of the Yarlung Tsangpo River are characterized by broad valleys inter-calated with gorges.The deep gorges are easily dammed.However,the damming event of the Dazhuka dammed palaeo-lake was unclear.To explore its causes,We studied the deep valley area of the middle Yarlung Tsangpo River,specifically at the south bank of the outlet of the Dazhuka-Yueju gorge.Herein,the geomorphological features and particle sizes of the sediments were ana-lyzed.The results suggest that the upper part of the valley is covered by moraine,and the lower part is covered by debris flows.The sedimentary features indicate an outburst of a periglacial lake event in the valley.The burst flood carries moraine,and washes the valley weathered debris material,forming debris flow.The high energy debris flow poured down to the Yarlung Tsangpo River and formed a dam,which is likely the dam of the Dahzuka palaeo-lake.With the global warming of the modern climate,the periglacial lake is easily failed and leads to outburst floods on the Tibetan Plat-eau.This research has guiding significance for disaster prevention and reduction in this region.
Late PleistoceneDazhuka-Yueju valleyparticle sizedamming event
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