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Integrated modelling of riverine levee breaches and subsequent inundation of protected areas
Citation Link: https://doi.org/10.15480/882.14128
Publikationstyp
Doctoral Thesis
Date Issued
2025
Sprache
English
Author(s)
Herausgeber*innen
Advisor
Referee
Title Granting Institution
Technische Universität Hamburg
Place of Title Granting Institution
Hamburg
Examination Date
2024-05-17
Institute
TORE-DOI
First published in
Number in series
27
Citation
Hamburger Wasserbau-Schriften 27: (2025)
Levees are earthen embankments, often constructed from locally available soil material, used to contain floodwaters in rivers. Levee design standards have improved over time, contributing to their reliability in providing flood protection. However, levees never provide absolute flood protection. The preparation of flood hazard maps for areas behind levees is therefore indispensable. Flood hazard maps can be produced using hydrodynamic numerical models that simulate flood inundation. The modelling of flood inundation due to levee breaching involves the modelling of two processes: i) the breaching of the levee and ii) the propagation of the flood through the resulting opening into the hinterland.
This thesis proposes the modelling of flood inundation due to levee breach with a 2D hydrodynamic numerical model with an integrated parametric levee breach model. To model levee breaching, a parametric levee breach model is developed, which is based on analyses of physical levee breaching experiments and of real levee breaches. The breach model is then integrated into the hydrodynamic numerical model Telemac-2D, a publicly available code for modelling flood propagation.
The thesis also developed methods for estimating the parameters of the parametric breach model based on historical (available) levee breach data. Regression fitting for the final breach width is performed using multiple linear regression, multiple non-linear regression and artificial neural networks. In addition, an approach is developed to estimate a possible breach location based on flood characteristics (water level and flood duration), geometric and geological characteristics of the levee in question and its foundation, the cause of the breach, and information from historical levee breaches on their breach location.
By re-modelling physical laboratory tests simulating levee breaching, this work has demonstrated that the hydrodynamic numerical model, Telemac-2D, is a suitable tool for modelling flood inundation due to levee breaching. The flood inundation caused by the levee breach on the Awash River at Wonji, Ethiopia in August 1996 could be reproduced using the proposed integrated approach. Furthermore, the determination of the breach location for this levee breach case using the approach proposed in this thesis resulted in the same location as the actual breach location, demonstrating the general applicability of the approach.
The uncertainties associated with the models used are also discussed. To demonstrate the uncertainty associated with the breach model, the sensitivity of flood inundation depth and breach discharge to variation of the levee breach parameters is systematically analysed using the August 1996 Awash River levee breach flood event at Wonji, Ethiopia.
This thesis proposes the modelling of flood inundation due to levee breach with a 2D hydrodynamic numerical model with an integrated parametric levee breach model. To model levee breaching, a parametric levee breach model is developed, which is based on analyses of physical levee breaching experiments and of real levee breaches. The breach model is then integrated into the hydrodynamic numerical model Telemac-2D, a publicly available code for modelling flood propagation.
The thesis also developed methods for estimating the parameters of the parametric breach model based on historical (available) levee breach data. Regression fitting for the final breach width is performed using multiple linear regression, multiple non-linear regression and artificial neural networks. In addition, an approach is developed to estimate a possible breach location based on flood characteristics (water level and flood duration), geometric and geological characteristics of the levee in question and its foundation, the cause of the breach, and information from historical levee breaches on their breach location.
By re-modelling physical laboratory tests simulating levee breaching, this work has demonstrated that the hydrodynamic numerical model, Telemac-2D, is a suitable tool for modelling flood inundation due to levee breaching. The flood inundation caused by the levee breach on the Awash River at Wonji, Ethiopia in August 1996 could be reproduced using the proposed integrated approach. Furthermore, the determination of the breach location for this levee breach case using the approach proposed in this thesis resulted in the same location as the actual breach location, demonstrating the general applicability of the approach.
The uncertainties associated with the models used are also discussed. To demonstrate the uncertainty associated with the breach model, the sensitivity of flood inundation depth and breach discharge to variation of the levee breach parameters is systematically analysed using the August 1996 Awash River levee breach flood event at Wonji, Ethiopia.
Subjects
Riverine levee breaches | Levee breach models | Flood inundation modelling | Parametric levee breach model | Levee breach parameters | uncertainties in modelling flood inundation
DDC Class
551: Geology, Hydrology Meteorology
627: Hydraulic Engineering
519: Applied Mathematics, Probabilities
623: Military Engineering and Marine Engineering
004: Computer Sciences
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Tadesse_Yohannis_Birhanu_2025_Integrated-Modelling-of-Riverine-Levee-Breaches-and-Subsequent-Inundation-of-Protected-Areas.pdf
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