Document Type : Research Article
Expert of National Center for Climate and Drought Crisis Management
Expert of the National Center for Climate and Drought Crisis Management
Expert of Meteorology, Saghez Meteorological Office, Saghez, Iran
The purpose of this study is to investigate the changes in Iran's climate zones during the periods (1965-1975, 1976-1985, 1986 -1955, 1996-2005, 2006-2015. For this purpose, the weather data (minimum, maximum, average), humidity (minimum, maximum, average), rainfall, wind and sunshine for 411 synoptic stations during the period 1965 to 2015 were collected and analyzed by the country's Meteorological Organization. Also, the ESFZARI database was also used in two sections. The first part was formed with the help of 1434 stations from the beginning of 1961 to 2004 and the second part from 2004 to 2015 with the help of 960 stations. At first, factors influencing the climate of Iran were analyzed by factor analysis and then clustered by using cluster analysis. In order to validate the identified areas, silhouette analysis was used. The results showed that most of the spatial variations during the five periods studied were very hot and dry (very low rainfall and high temperature), warm and dry areas (low rainfall and high temperatures), and cold and dry (low rainfall and low temperature) experience So that each of these three areas, for example, the cold and dry (low rainfall and low temperature) areas of its range is reduced, on the contrary, the size of the two other areas is increased. This dimension of change in the first and second period has been quite evident. The results of the silhouette analysis also showed that more than 92 percent of the Iranian zone was located right in their group, which indicates the high validity of the identified areas.