Investigation of 1-D Numerical Simulations of Dam Break Flood Wave Propagation: Case of Rahmanlar Dam

Abstract

Determination of flood wave propagation occuring as a result of dam break is an important and essential study in determining risks on any residential, commercial or agricultural areas located in downstream regions of that dam. Today, numerical model simulations are widely used for such studies. Within the scope of this study, 1-Dimensional (1D) analysis of dam break of the Rahmanlar Dam, which is about to be completed in the Ödemiş District of İzmir was conducted to determine whether or not the flood wave occurred as a result of dam break would reach the three villages located at the downstream of the dam. In the study, the HEC-RAS (Hydrologic Engineering Center’s River Analysis System) was used for 1D simulations. Flooded areas have been mapped according to the results of model analysis and the maximum water surface elevations and the time of occurrence of peak discharges have been determined. According to the simulations of different dam break scenarios, it was noted that the physical properties of land and stream flow could not be identified with desired accuracy in the model due to the unidirectional flow propagation in 1D dynamic analysis and this might affect the results of the model. However, when the computational time of the model analysis was taken into account, it was found that the analysis were completed in a short period of time like one hour or so. Therefore, 1-D analysis should be carried out for safety analysis of the downstream regions of any dam in Turkey either in operation or design stage depending on the importance and urgency of the study. After evaluation of those results, it is recommended to perform 2-Dimensional analysis and, if necessary, 3-Dimensional analysis.

Keywords

• Dam break
• HEC-RAS Wave propagation Rahmanlar Dam
• HEC-RAS
• Wave propagation Rahmanlar Dam
• Wave propagation
• Rahmanlar Dam