[H-DS12] Geohazards in humid, tectonically active countries and their precursors

[HDS12-P08] Gigantic landslides distributed in the upper course of Marsyandhi river in Nepal Great Himalaya

*Hiroshi YAGI¹, Yuki Matsushi², Hiroshi P Sato³, Akihiko Wakai⁴ (1.Faculty of Art, Science and Education, Yamagata University, 2.DPRI, Kyoto University, 3.College of Humanities and Sciences, Nihon University, 4.Faculty of Technology, Gunma University)

Keywords:Nepal Great Himalaya, gigantic landslide, Marsyandhi river

There develop gigantic landslides of which scale are more than half billion cubic meters along the upper course of Marsyandhi river in the Nepal Great Himalaya just behind the Annapurna Himal. Landslides in scale of million cubic meters are also sporadically distributed along the gorge which the Marsyandhi divides Annapurna & Manasul massifs. Some of them are absence of their detritus. Such phenomena indicate that the huge volume of detritus were flushed away to the down stream as debris flow.