Flood Flow Calculation and Flood Modeling in Rivers That Do Not Have Enough Flow Measurement (Samsun, Mert River Sample)

Abstract

Floods are among the most important disasters in the world. After the earthquakes in terms of loss of life and property in Turkey in second place, it takes the first place among meteorological disasters. It is very important to investigate the structure of this disaster affecting our lives and economy and to take measures to minimize losses. The aim of this study is to obtain flood return period flow rates by using unit hydrograph methods for Samsun, Mert river which does not have enough flow measurement and to model flood propagation of flood hydrographs in return periods. The Mockus, Synder and DSI Synthetic methods based on precipitation-flow modeling were used in the determination of flood return period hydrographs. The precipitation data of the stations covering the Mert River basin were used in the application of the methods. The distribution that best matches the maximum precipitation data in return periods was determined using statistical distributions. The statistical distributions used are Normal distribution, Log-Normal distribution, Gumbel, Log-Pearson, Pearson distributions. The most appropriate distribution was determined by the Kolmogorov-Smirnov conformity test. Then, maximum precipitation heights were obtained, and current values and hydrographs were obtained. Thus, the flood modeling phase of the study was passed, and the flood flow rates obtained were modeled by using the FLO-2D program. Flood propagation areas and water heights were examined in different return period and suggestions were made for the bridges and urban areas near the river.