عنوان مقاله [English]
نویسندگان [English]چکیده [English]
From the viewpoint of many experts in climatology, climate fluctuation is considered a natural phenomenon repeated in the course of a long-term cycle. This study will analyze the elements of temperature, precipitation and evaporation in the northern mountains of the Karkas range in terms of seasonal and annual cycles, using a non-parametric test of Man-Kendall during two time periods from 1980 to 2009 and from 2007 to 1987. Based on the results, the data with a confidence level of 95% indicate that the days with a precipitation of over 10 mm especially during the winter suggest no certain trend. The years 1987-2007 indicate an increasing trend towards higher temperatures and evaporation compared to the period of 1980-2009, so that the annual averages and the maximum and minimum temperatures show a significant increasing trend, but no trend of precipitation or evaporation is seen. The regression line of evaporation, however, showed an increase of 2 to 16 millimeters per year, a process suggesting increased water demands, reduced soil moisture, decrease in pastures and agricultural products, and exerting more pressure on underground water resources.