عنوان مقاله [English]
One of the ways to assess the rainfall trends in the past and present is through trend analysis of time series of rainfall at different scales of time. The aim of this study was to analyze the spatial and temporal trend of annual rainfall in Iran using Aphrodite's database. In this study, using the quality- controlled resulting outputs of Aphrodite cell precipitation database in order to assess the trend of the country's Iran's annual rainfall. The base data for the period of 1950 to 2007, and with the spatial resolution is of 0.25 × 0.25 and 0.5 × 0.5 degrees were used. Iran's annual precipitation trend was calculated using non-parametric Mann-Kendall method and in order to estimate the slope of trend the age line slope method was conducted. The results of the analysis of these data showed that in the time series of mean cell and Iran precipitation stations of Iran precipitation, there is was no significant increasing or decreasing trend at confidence levels of 99 and 95%. Age test statistics at the assessed confidence levels showed that the average rainfall of Iran has increased by about 0.439 mm/yr per year. In addition, the minimum and maximum decrease in rainfall at 99% level was -0.476 and 1.321 mm respectively. While the minimum and maximum Iran cellular precipitation at 95% level was estimated to be -0.221 and 1.088 mm respectively.