Studying the climate change of Markazi province by Mann-Kendall

This research aims to study the change in climate elements in Markazi province from 1966 to 2005 (for 40 years) in the monthly, seasonal and yearly time-scales. In this regard, the statistic average of minimum and, maximum temperature and precipitation have been processed at the Arak, Shams Abad, Tafresh and Saveh stations over this province. After reconstruction of the missing data with interpolation method by using Surfer software, data abnormality by Ncss software and Kolmogorov-Smironov test, their homogeneity were evaluated by Runs test. Then data trend was studied and the random changes were identified using Mann-Kendall,s statistical-graphical test and then the type and time of the changes were studied. According to the results obtained from the temperature average parameters, most of the months have been observed with no change and only in some of the months positive trends observed in Tafresh and Saveh stations. Studying of precipitation parameter indicate a negative trend of all stations from June to September and the lack of trend in other months. The results of studies about the time and kind of changes show that the most of the temperature average changes have of suddenly decreasing and the precipitation indicates a decreasing trend from June to October.