Technical NoteAn innovative method for trend analysis of monthly pan evaporations

- Trend analysis of pan evaporations is performed by an innovative trend (IT) method.
- IT results are compared with commonly used non-parametric Mann-Kendall (MK) method.
- A significantly decreasing trend was found for the Adiyaman Station (Turkey).
- Diyarbakir and Kilis stations located in Turkey showed significantly increasing trend.
- The advantages of innovative methods to the MK are clearly presented.

SummaryTrend analysis of monthly pan evaporations was performed by using recently developed innovative trend analysis (ITA) method. The ITA was applied to the monthly pan evaporation data of six different locations, Adiyaman, Batman, Diyarbakir, Gaziantep, Kilis and Siirt in Turkey. Monthly trends of pan evaporation were also investigated by commonly used non-parametric Mann-Kendall (MK) method. According to the MK method, a significantly decreasing trend was found for the Adiyaman Station while the Diyarbakir and Kilis stations showed significantly increasing trend at the confidence level of 10%. No trend was found for the Batman, Gaziantep and Siirt stations with respect to MK. The ITA results indicated that the low, medium and peak pan evaporation values of the Batman, Gaziantep and Siirt stations had some increasing and decreasing trends although no trend was found for these stations according to the MK test. The main advantages of innovative method are that it is not dependent on any assumption such as serial correlation, non-normality and sample number and trends of low, medium and high data can be easily observed by this method.