عنوان مقاله [English]
Wind is one of the main elements in the climate of each region,and its changes can affect phenomena such as dust storms and the severity of evapotranspiration.The declining trends of surface windreported by previous studies are generally small, but it is still important to assess the distribution of the trend of wind speed at the continental to global scale in order to betterunderstand the causes of the trend. This research was carried out aiming to predict wind speed in Iran by 2020 with the Holt-Winters model and using data from a 50-year statistical period (1961-2010). The results showed that this model has the ability to predict wind speed in most parts of the country. The values of the coefficient of explanation of this model varied in 34 stations under survey from 0.39 in Abadan to 80.0 in Babolsar, and the error values in most of these stations were acceptable. The results of Kolmogorov-Smirnov test used to evaluate the normalized residuals of model showed that the model residuals are normal in most of the stations that show the suitability of the model to estimate and predict the wind speed in Iran.The results showed that this model has also simulated the wind speed extreme values in most stations as well. The results of the Holt-Winters model to predict wind speed by 2020, indicate that wind speed in the Eastern half of the country as well as the southern slopes of the Alborz, which have dry and semi-arid climates, will increase by 2020, while the Western half, Southwestern and central regions of the country will experience a decreasing trend of wind speed. The maximum amount of wind speed increase will be at Gorgan station by 2020 with a value of 1.8 meters per second, and themaximum rate of wind speed reduction will occur in southwest stations of the country, so that in the Abadan station, wind speed will decrease from 48.6 m / s to 31.8 m / s by 2020.In other words, we can say that the wind speed in most arid and semiarid regions of the country will increasein the future, while moderate and mountainous areas in western parts of the country will experience a decreasing wind speed.