Investigation of Effective Meteorological Parameters Variations in Urmia Climate

One of the atmospheric cycle properties is climatic changes which can cause the fluctuations in meteorological parameters. These fluctuations in many world regions are considerable and water and soil resources are affected by them. To prepare against undesirable effect of climate change and adopt suitable development programs and water resources management، it is necessary to investigate the meteorological variable changes. The objective of this research was to investigate the climate change in Urmia region. In this research، the changes trend of temperature، precipitation، relative humidity، sunshine and potential evapotranspiration were studied. To achieve this goal، Urmia synoptic station daily data with 40 years period (1971-2010) were used. The Mann-kendall statistical test at confidence level of 95% was used to investigate the significance of trend in the mentioned parameters. The results showed that the trend slope of maximum، minimum and average of temperature was positive and this trend in 95% confidence level was significant. Urmia precipitation was decreased with slope of -2. 26 so that this decrease was significant. The sunshine had positive slope and significant trend، but the negative trend of relative humidity and the positive trend of potential evapotranspiration (0. 0068) were not significant. The monthly investigations showed that the average temperature in all months had positive slope، but this slope was not significant in all months. The other parameters in some months had positive or negative slopes.