Evaluation of Susurluk Basin Flows Using Trend Analysis Methods

Trend analysis of annual average flow data is very important for better water resources management, planning and operation. In this study, annual average flow data from M. Kemal Paşa, Orhaneli and Simav flow observation stations located in Susurluk Basin were tested with Mann-Kendall, Spearman Rho and Şen's Innovative trend methods and the trends of the stations were tried to be determined and the performances of these methods were evaluated. In addition, annual average flow data were submitted to regression analysis, yielding equation sets. For each station, the annual and 100-year changes in m3/s were determined. Analyzing the results, only Şen's Innovative Trend Method analysis found a general decreasing trend for all 3 stations. In the analyses of Mann-Kendall and Spearman’s Rho methods, no trend was detected in all 3 stations. In addition, 100-year percentage change values of the data of 3 stations were determined. According to these values, it is concluded that there will be a significant decrease in the flow values of the stations in the future.