IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 35th IAHR Congress - Chengdu (2013) : THEME 7 - WATER RESOURCES AND HYDROINFORMATICS : 2D Modelling of Megaflood due to Glacier Dam-break in Altai Mountains, Southern Siberia
2D Modelling of Megaflood due to Glacier Dam-break in Altai Mountains, Southern Siberia
Author : Wei Huang, Zhixian Cao, Paul Carling and Gareth Pender
One of the largest known megafloods due to glacier dam-break is that occurred during Late Quaternary in Altai Mountains, Southern Siberia. Hydrodynamic modelling is one of the viable approaches to enhancing the understanding of the ancient flood due to glacier dam-break. A well-balanced two dimensional hydrodynamic model, which can properly capture shock waves, cope with rugged bed topography and handle drying and wetting interface transition, is deployed to reconstruct the flood on the area which involves Chuya River, Katun River and Uimon Basin. The computational area is over 9460 2 km and about 3.784106 cells are involved as 50 m 50 m mesh is used. In addition, the duration of the flood is 48 hours. Thus long computational time is required. To enhance the efficiency of the model, the OpenMP (Open Multiprocessing) technique is adopted to parallelize the code. The full process of the flood wave is well reproduced with specified discharge hydrographs at the dam site. The computed maximum stage profile agrees with field data rather well. The shape and peak value of the inlet discharge hydrograph at the dam site may influence the process of the flood. Moreover, the Manning roughness in relation to bed friction is also a major source of uncertainty. A sensitivity analysis of the impacts of the aforementioned three factors is carried out. It is shown that the influences of Manning roughness and shape of the inlet discharge hydrograph are marginal compared to that of the value of peak discharge. Besides the understanding of the spatial and temporal hydraulics of the megaflood, the implications of sediment transport and geomorphology during the flood are presented.
File Size : 769,736 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 35th IAHR Congress - Chengdu (2013)
Date Published : 19/07/2016
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