The Short-Term and Seasonal Trend Detection of Sediment Discharges in Turkish Rivers

Abstract

Hydrometeorological variables are tested by trend methods to be able to detect trends in river basins. Mann-Kendall, Spearman’s rho tests are widely used as traditional trend methods. Besides that, some new trend tests are applied to hydrometeorological variables as Innovative Trend Analysis (ITA). Sediment discharge observations are more difficult than other hydrometeorological variables. In general, sediment data are observed in monthly time scale. Therefore, there are very limited studies on sediment data, especially in Turkey. In this study, Innovative Trend Analysis (ITA), Mann-Kendall, Correlated Mann-Kendall and Seasonal Mann-Kendall trend analyses are applied to sediment discharges in Turkish river basins. According to Mann-Kendall, Correlated Mann-Kendall and Seasonal Mann Kendall results, positive trends have detected only 8, 2 and 20 gauging stations, respectively. Then, 30 positive and 15 negative trends by ITA methodology. The trend slopes calculated from ITA methodology are categorized because some positive and negative of trends are weak. The applied trend methods are evaluated together considering climate properties of hydrological regions in Turkey. Increasing trends on sediment data are detected from the rivers from Mediterranean region of Turkey. The results of the study would help to manage water resources as well as sustainable development in the Turkish river basins.