Investigation on the Climatic Parameters Fluctuation Using Data from the The European Centre for Medium-Range Weather Forecasts (Case study: Shirkouh Region - Yazd Province)

Any changes in the climate system affect on the access and management of natural resources such as water and soil. Temperature and precipitation are the key elements of climate for studying their trend can be important for atmospheric scientists, environmental managers and planners in the field of hydrology, agriculture, environment and so on. In this study, the trend of climate fluctuations was investigated using the ERA-Interim data. In the first step, calculating RMSE, MAE and Pearson correlation coefficient, the accuracy monthly data of ERA-Interim was studied using synoptic data of Yazd city. The monthly data with the least error and the highest correlation were selected to analyze the changes trend. Then, the selected data including the temperature of two meters above ground level, the soil surface temperature in depth of 1-7 cm, soil temperature in depth of 7-28 cm and synoptic monthly means precipitation were modified by the TerrSet software using the test Mann Kendall. The results showed that the northern and central western parts of the study area had a decreasing trend of precipitation variation at a level of 5% and in the rest of the areas changes are not significant. Also, studying the trend of temperature variables showed that soil temperature changes in two meters above ground level, in depths of 1-7 and 8-28 cm was significant at 1% level in all of study area. The change in the Z test of Mann Kendall was greater than 4.8 everywhere.