Flood simulations based on breach parameters of Tuzluca dam reservoir and its effects on the downstream area

In this thesis, 2D and 3D numerical failure simulation of the Tuzluca Dam, which is planned to be built in Iğdır Province of Turkey, was carried out using FLOW3D software. RNG k-ε was chosen as the turbulence model in the analyzes using Shallow Water Equations (SWE) and Reynolds-Averaged Navier-Stokes (RANS) equations. In the scenarios created with different breach geometry and failure times, serious water depths were detected in two settlements in the downstream region in both solution methods (2D SWE and 3D RANS). For 2D analyses, maximum water depths of 11.26 m and 9.61 m were observed in Halimcan and Sürmeli settlements, respectively, under the relevant scenario conditions. In 3D analyses, the maximum water depths for Halimcan and Sürmeli settlements were determined as 9.9 m and 8.9 m. In the simulations in question, the peak flow rates occurring at the dam axis were observed as 67323 m3/sec in 2D analyses and 69446 m3/sec in 3D analyses. Within the scope of the study, mortality rates and speed-depth multiplications in different failure scenarios of the Tuzluca Dam were also investigated. It has been observed that dam failure time and breach geometry have a significant impact on flood propagation, flood severity and mortality rates in settlements. As a verification analysis, a dam failure experiment in the literature was solved numerically using FLOW3D software and a satisfactory agreement was observed between the experimental results and the numerical model results. Although the 3D numerical model provides a more accurate representation of the experimental results, the solution time of the simulation in the failure analysis of the Tuzluca Dam, which is the main subject of the study, takes approximately 20 times longer than the 2D model. For this reason, it has been determined that 2D analyses may be more practical for large-scale studies such as dam break, while 3D modeling will be suitable for smaller-scale studies or situations requiring more precision.