Flood events and their effects in a Himalayan mountain river: Geomorphological examples from the Buri Gandaki Valley, Nepal Flood events and their effects in a Himalayan mountain river: Geomorphological examples from the Buri Gandaki Valley, Nepal

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Vol14 No.7: 1303-1316

Title】Flood events and their effects in a Himalayan mountain river: Geomorphological examples from the Buri Gandaki Valley, Nepal

Author】Gerrit TOMBRINK

Addresses】Institute of Geography, University of Göttingen, Goldschmidtstraße 5, 37077 Göttingen, Germany

Corresponding author】g.tombrink@mailbox.org

Citation】Tombrink G (2017) Flood events and their effects in a Himalayan mountain river: Geomorphological examples from the Buri Gandaki Valley, Nepal. Journal of Mountain Science 14 (7). DOI: 10.1007/s11629-016-4154-5

DOI】10.1007/s11629-016-4154-5

Abstract】This research examines flood events and related human interactions in the northwestern Himalayan Buri Gandaki Valley (Nepal). Past flood events that left traces at elevations between 3745 m to 780 m above sea level were investigated and reconstructed using morphometric and descriptive fluvial geomorphological analyses of historical flood markers and their related forms in the Buri Gandaki River system. Furthermore, the discharge of the Buri Gandaki River was measured, and infrastructure and permanent and temporary settlements potentially influenced by floods in the region due to their proximity to natural hazard areas were mapped. All reconstructed flood indicators have been documented with photographs that illustrate the evolution of the landscape over a short period in the Holocene. Moreover, satellite images have confirmed the morphological findings at the mesoscale and macroscale. An analysis of the flood levels showed that the high-water marks between 2160 m and 1710 m above sea level represented the highest reconstructed paleoflood stages.

An intense flood hazard was observed in the upper stream of the Buri Gandaki near the Birendra Kund glacial lake and Samagaun settlement (3520 m above sea level). Further conclusions may be drawn from the anthropogenic reactions to flooding, such as those of the ethnic groups in this valley, who have used their local knowledge of floods and highdischarge events along the Buri Gandaki River to takesafety precautions. Thus, local knowledge has reduced the social vulnerability in the settled areas of the valley. As a result of these local adaption strategies within the valley, we must rethink our implementation of protection and urbanisation strategies.

Keywords】Floods; Vulnerability; Fluvial geomorphology; Himalaya; Buri Gandaki; River