A1 Refereed original research article in a scientific journal
Comparing a 1D hydraulic model with a 2D hydraulic model for the simulation of extreme glacial outburst floods
Authors: Alho P, Aaltonen J
Publisher: WILEY-BLACKWELL
Publication year: 2008
Journal:Hydrological Processes
Journal name in sourceHYDROLOGICAL PROCESSES
Journal acronym: HYDROL PROCESS
Volume: 22
Issue: 10
First page : 1537
Last page: 1547
Number of pages: 11
ISSN: 0885-6087
DOI: https://doi.org/10.1002/hyp.6692
Abstract
Glacial outburst floods jokulhlaups) destroy a significant amount of infrastructure in proglacial areas. Nevertheless, few studies have simulated extreme jokulhlaup inundation using hydraulic modelling. In this study, we demonstrate the capability of one-dimensional jokulhlaup simulation (HEC-RAS modelling software) and compare simulation results with those from a two-dimensional finite element model (TELEMAC-2D modelling software) to determine the potential and limitations of one-dimensional modelling for jokulhlaup simulations. In both models, a pre-defined hydrograph was used as an upstream boundary condition for the jokulhlaup, which was simulated on the Moarudalur floodplain, northeast Iceland. An unsteady flow simulation of the rising stage of the flood (5 h 15 min) was undertaken with both models to produce maps of flood inundation and flow depth. The study shows that simulations had a 200 m horizontal difference in inundated area at the peak discharge stage. Additional differences were also detected in the rising stage of the hydrograph. The most significant differences between the models was found at the time when the front of the jokulhlaup inundated a new area through a sinuous gorge, or when inundation took place through a complex flow route (maximum difference similar to 1800 m). This study demonstrates that one-dimensional modelling of jokulhlaup propagation provides results broadly comparable to data derived from more complex simulations. Copyright (c) 2007 John Wiley & Sons, Ltd.
Glacial outburst floods jokulhlaups) destroy a significant amount of infrastructure in proglacial areas. Nevertheless, few studies have simulated extreme jokulhlaup inundation using hydraulic modelling. In this study, we demonstrate the capability of one-dimensional jokulhlaup simulation (HEC-RAS modelling software) and compare simulation results with those from a two-dimensional finite element model (TELEMAC-2D modelling software) to determine the potential and limitations of one-dimensional modelling for jokulhlaup simulations. In both models, a pre-defined hydrograph was used as an upstream boundary condition for the jokulhlaup, which was simulated on the Moarudalur floodplain, northeast Iceland. An unsteady flow simulation of the rising stage of the flood (5 h 15 min) was undertaken with both models to produce maps of flood inundation and flow depth. The study shows that simulations had a 200 m horizontal difference in inundated area at the peak discharge stage. Additional differences were also detected in the rising stage of the hydrograph. The most significant differences between the models was found at the time when the front of the jokulhlaup inundated a new area through a sinuous gorge, or when inundation took place through a complex flow route (maximum difference similar to 1800 m). This study demonstrates that one-dimensional modelling of jokulhlaup propagation provides results broadly comparable to data derived from more complex simulations. Copyright (c) 2007 John Wiley & Sons, Ltd.
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