Document Type : Original Article
Researcher at Malek Ashtar University of Technology, Iran
The impact of climate change on natural resources has become one of the greatest human concerns at the local, regional and global levels in recent years. One of negative impact of climate change is change of aridity index trend and transformation of hydro-ecological conditions in different regions. The main objective of this research is to evaluate the trend of Aridity index (IA) in northern stations of Iran during the period 1982-2009. To do so, the Penman equation was used to calculate the daily potential evaporation. Thereafter, the drought index values were calculated using the precipitation and potential evaporation parameters. Results demonstrate that precipitation values have been decreased during 1982-2019 in northern strip of Iran, so that precipitation has decreased by 300 mm during 2012-2019 in Bandar-e-Anzali station compared to the 10-year period (1982-1991). Temperature values have also increased in the northern stations of the country. Air temperature has increased about 1, 1.7, 0.1, 1.9 and 1.) 5C° ) in Rasht, Ramsar, Gorgan, Babolsar and Bandar-e-Anzali stations respectively. Furthermore, drought index represents a decreasing trend in all studied station during 1982-2019. The trend of Aridity index during 2019-2012 compared to the 10-year period (1982-1991) are -0.178, -0.011, -0.091, -0.142 and -0.420 in Rasht, Ramsar, Gorgan, Babolsar and Anzali stations, respectively.