Trend Analysis of Hydrometeorological Parameters in Climate Regions of Turkey

1. BALWOIS 2010 Conference on water observation and information systems for decision support 25-29 May 2010, Ohrid, Republic of Macedonia Trend Analysis of Hydrometeorological Parameters in Climate Regions of Turkey Hakan Aksu General Directorate of State Hydraulic Works, Ankara, Turkey

2. Objectives Investigation of trends 1. Long term precipitation data 2. Long term temperature data 3. Long term estimated evapotranspiration values  Understanding trends in spatial extent.  Understanding trends in temporal extent • Clues for climate change.

3. Data and Methodology 1. • Long term annual total precipitation • Long term annual average temperature • Between 1950-2005 years • 14 stations all over Turkey • Swed- Eisenhart test was applied for temperature and precipitation data • Only one station (Alanya) showed inhomogenity. For this reason Alanya was not analysed for trend anaysis.

4. Data and Methodology 2. • Evapotranspiration time series were generated by Turc formula (Turc, 1961) • Kolmogrov-Smirnov normality test was performed for 90% confidence interval. Results are presented in table 1. • The pearson’s correlation r was used in order to detect linear trend in homogenous on normally distributed time series

6. Data and Methodology 3. • Significance of pearson’s r was checked by the student’s t test (95%) • The other method non parametric Man Kendall test was applied to all homogenious time series.

7. RESULTS

8. RESULTS

9. RESULTS

10. FINDINGS • If the Kendall test z values bigger than 20, at that time regression trend test gave the same result. • The value of 0,02 value for the slope temperature regression equation can be evaluated as a reference level for upward evapotranspiration trends (Table 5). • Majority of stations shows upward trend on temperature and evapotranspiration. One except all stations shows no trend on precipitation.

11. THANK YOU!