Geomorphic effects of recurrent outburst superfloods in the Yigong River on the southeastern margin of Tibet

Abstract Landslide dam outburst floods have a significant impact on landform evolution in high mountainous areas. Historic landslide dams the Yigong River, southeastern Tibet, generated two superfloods > 10 5 m 3 /s 1902 and 2000 AD. One of slackwater deposits, which was newly found immediately downstream historic dams, has been dated to 7 ka BP. The one-dimensional backwater stepwise method gives an estimate 225,000 for peak flow related paleo-stage indicator recurrence at least three large impoundments super-outburst exit Lake during Holocene greatly changed morphology River. More than 0.26 billion sediment aggraded dammed lake while doubles channel slope behind dam. Repeated damming may be persistent source impede upstream migration river knickpoints margin Tibet.