Flood analysis of Sivas 4 Eylul Dam according to dam break scenarios and preparation of flood hazard report

Dams provide significant benefits for humanity such as flood control, hydroelectric power, water supply, irrigation and recreation. Although dams are high safety measures, past catastrophes have shown that dams can be destroyed. In addition, the importance of flood analysis in the regions with high population density was seen in flood events experienced in previous years. In this thesis, Sivas 4 Eylül Dam, which meets the drinking water requirement of the Mısmılırmak Creek and the Sivas Province, passing through the Sivas Province, was gradually demolished and flood analyzes were performed. DSI Synthetic Method was used to obtain flood hydrographs. Modified Cowan (State Hydraulics Works (SHW) Format) Method was used to calculate the creek bed roughness coefficient. Numerical elevation model was obtained by using 1/1000 maps as base for numerical modeling. With MIKE 11 program, two dimensional hydrodynamic models were created with MIKE 21 program and flood analysis was performed. The 1D model was used to test the adequacy of the river bed cross sections, and the spread of the flood in the field was examined with the 2D model. According to the situations where the dam is effective and ineffective, flood hazard maps were created and areas under risk were determined. Suggestions were made to prevent the flood caused by Mısmılırmak and Sivas 4 Eylül Dam in Sivas city center. Keywords: Hydrodynamic Analysis, MIKE 11, MIKE 21, Sivas 4 Eylül Barajı, Flood Maps.