Observed trends in mean, maximum and minimum temperatures in büyük menderes basin after 1970

In this study, considering climate change phenomenon, it is aimed to investigate temporal trends of mean, maximum and minimum temperatures in monthly, seaonal and annual scales using temperature data recorded at nine stations (between 1972-2011 at Sultanhisar and Nazilli and 1970-2011 at Aydın, Denizli, Dinar, Uşak, Güney and Yatağan) in Büyük Menderes Basin, operated by State Meteorological Service of Turkey (Metetoroloji Genel Müdürlüğü). Firstly, temperature series were subjected to homogeneity analysis using Runs test. Statistical significance of trends were assessed by non-parametric Mann-Kendall test and magnitudes of trends were quantifed by Sen's Slope Estimator. Series having significant serial correlation at %5 level and high coefficient of variation were applied Trend-Free Prewhitening procedure. The results showed that mean annual, mean annul maximum and mean annul minimum temperatures experienced statistically significant increasing trends at most of the stations. The highest trends for mean annual maximum, mean annual minimum and mean annual temperatures were 0.062 °C/year at Yatağan, 0.067 °C/year and 0.050 °C/year at Denizli, respectively. Summer season and summer months were the periods which had statistically significant increasing trends and the highest trend magnitudes. Other seasons and months had nonsignificant trends, either increasing or decreasing. It seemed that increasing trends in annual averages can be attributed to the increases in summer months