عنوان مقاله [English]
In this study, to evaluate the trends of precipitation data from a gridded of daily precipitation database the APHRODITE precipitation database of the Middle East for Iranian territory with resolution 0.25* 0.25 degrees Latitude and Longitude have benefited. Then time series of monthly, quarterly and annually for a period of 50 years from 1956 to 2006 based on the data and calculations in this study were extracted. With nonparametric statistical method - a numerical and graphical- Mann-Kendall test means the average annual rainfall, seasonal, monthly and Sen’s method slope, the slope of the trend line was tested. The results suggest that in time series of annual, seasonal and monthly in Confidence interval 95%, and more than that There is no significant trend, Apart from the precipitation time series December which means in Confidence interval 95%. Average annual precipitation of pixel last half century APHRODITE base in about 0.73 mm increased These seemingly insignificant considering the country's area in makes about 1203182135 cubic meters of precipitation per year; Despite the increasing trend in annual precipitation, a decreasing trend in precipitation time series months of April, May and June and the spring seasonal time series which is much needed rain for farming and it can cause problems in the production and supply of food to be brought.