Wind Speed Trends in Iran

Investigation of wind speed trend and analysis of its effective can be a suitable index to environmental variability related to air movement. Any increase or decrease in wind speed over time can impact on agriculture, soil erosion, wind energy production, construction, mental health, and etc. In this study, wind speed trends and line slope by using Mann-Kendall nonparametric test and Sen’s slope estimator were evaluated using wind speed data from 96 synoptic stations of Iran during their recorded period. Zoning of annual mean wind speed showed that four wind regions could be detected in Iran. Although the wind trend in Iran has no a certain temporal pattern, but in the northern half and mountain regions of the country, the trend is more pronounced. January and October with about 50%of the total station, and July and March with about 38% were observed maximum and minimum of the positive trends in the study area, respectively. Most of the area with negative trend is related to July by 13% and lowest is related to January, February, March and October by 6.25%. Generally, the positive trend is 43% and areas with negative trends is 9.3% of the total area of the country. Wind speed slope investigation shows that 75% of the country has positive slope and 25% of the country is with negative slope that have been expanded in all regions of the country. Most positive and negative slope is related to Gorgan and Chabahar Stations, respectively.