Assessment of flood hazards due to overtopping and piping in Dalaman Akköprü Dam, employing both shallow water flow and diffusive wave equations

2023-01-01
Yilmaz, Kutay
Darama, Yakup
Oruc, Yunus
Melek, Abiddin Berhan
This study was carried out to determine flood propagation using shallow water equations (SWEs) and diffusive wave equations (DWEs) to reveal how the flood modeling results differ in terms of flow depth, flow velocity, and hazard level. The solution methods were tested based on the hypothetical failure of the Dalaman Akköprü Dam resulting from two failure mechanisms: overtopping (OT) and piping (PP). A 2D hydraulic model was constructed using HEC-RAS to determine the propagation of flood waves due to the failure of the dam by the mechanisms selected. Froehlich equations were applied to predict the breaching parameters of the dam. After calibration, the hydraulic model was run to determine the possible flooding magnitude in the towns of Ortaca, Dalaman, and Dalyan. The flood arrival times, maximum flow depths, flow velocities, and hazard classes were obtained for the Dalaman, Ortaca, and Dalyan city centers, and the Dalaman International Airport from the hydraulic model results. The modeling results showed that the inundated area is similar for both the SWEs and DWEs solutions, while the flow depth and velocity results are significantly different due to the neglected convective acceleration terms of the SWEs when deriving the DWEs. Considering the modeling results, even though the DWEs provide a computational cost advantage, the reliability of the solutions should be examined against the SWEs. Hazard maps were generated for both solution methods and failure mechanisms. The results revealed that most of the settlements in the basin have H5 and H6 hazard classes with a high risk of structural damage. Therefore, the installation of early warning systems and evacuation of district centers were suggested as mitigation measures. A feasible evacuation plan for the neighborhoods, taking into account the flood arrival time of the failure scenarios, is needed.
Natural Hazards

Suggestions

On the Use of Shallow Water Equations in Hydraulics
Iscen, Behiye Nilay; ÖKTEM, NURAY; Yilmaz, Burak; Aydın, İsmail (2017-01-01)
Shallow water equations are widely used in inundation analysis and they are known to be successful in computation of floods over wide terrains. Flood propagation in between buildings in urban areas and flows around hydraulic structures such as bridges may not satisfy the assumptions of shallow flow and may display markedly more 3-Dimensional (3D) flow characteristics. However, for the convenience of fast numerical solutions, the shallow-current equations can also be used for such 3D flows and useful output ...
Determination of critical submergence depth at horizontal intakes
Haspolat, Emre; Göğüş, Mustafa; Köken, Mete; Department of Civil Engineering (2015)
The purpose of the study is to investigate the formation of air entraining vortices under both symmetrical and asymmetrical approach flow conditions in an experimental setup of a horizontal water intake structure composed of a reservoir-pipe system. To determine at which critical submergence the air entraining vortices forming; a series of experiments were conducted in the experimental setup with horizontal pipes of four different diameters. Approach channel side walls of the intake structure model are adju...
Study of wave impact loads on components of stilling wave basin on a vertical seawall
Altunbaş, Mustafa Gökay; Özyurt Tarakcıoğlu, Gülizar; Kısacık, Doğan; Department of Civil Engineering (2022-8-24)
In this study, the wave pressure on components of Stilling Wave Basin (SWB) is investigated by analyzing the physical model experiment data of wave pressures for various hydrodynamic conditions. SWB is a structure that can be used for optimizing the crest height to achieve lower overtopping conditions especially in urban areas. The experiments are based on assessing the performance of SWB on a vertical seawall for which limited research exists. Wave pressure data on the seaward storm walls (both rows) and t...
Analytical solutions for evolution and runup of longwaves over a sloping beach
Ceylan, Nihal; Kanoğlu, Utku; Department of Engineering Sciences (2019)
The initial value problem of the linear evolution and runup of long waves on a plane beach is analyzed analytically. The shallow water-wave equations are solved by integral transform and eigenvalue expansion methodologies. The results from linear solutions are compared with the solution of the nonlinear shallow water-wave equations confirming the runup invariance, i.e. nonlinear and linear theories produce same maximum runup. Then, existing analytical nonlinear solution for shoreline motion is implemented f...
Formation of air-entraining vortices at horizontal water intakes /
Zaloğlu, Cihan; Göğüş, Mustafa; Department of Civil Engineering (2014)
The goal of this study is to estimate the critical submergence depths of horizontal water intakes that have symmetrical and asymmetrical approach flow conditions by using empirical equations. Therefore a series of experiments were performed in a reservoir-pipe system dominated by gravity and controlled by a valve. On account of adjustable lateral walls, symmetrical and asymmetrical flow conditions were created at various Froude numbers. For a wide range of discharges and for three different pipe diameters, ...
Citation Formats
K. Yilmaz, Y. Darama, Y. Oruc, and A. B. Melek, “Assessment of flood hazards due to overtopping and piping in Dalaman Akköprü Dam, employing both shallow water flow and diffusive wave equations,” Natural Hazards, pp. 0–0, 2023, Accessed: 00, 2023. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85149480204&origin=inward.