Trends in drought patterns of Turkey

Trends in annual and seasonal drought patterns in Turkey were investigated on the basis of regionally averaged surface humidity index (SHI) series. For this purpose, two nonparametric approaches, Mann-Kendall test and Sen's T test, were used. For some regions, significant upward trends in fall SHI series were detected due to the increasing precipitation for the period 1951–1998. The North Atlantic Oscillation influences on the SHI series were also investigated and significant negative correlations were found for some regions.Key words: drought, trend, Mann-Kendall test, Sen's T test, Turkey, North Atlantic Oscillation.