عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Heat waves are one of the most important climatic hazards that have damaging ecological environment impacts on the nature every year. For this purpose, the aim of this research is identifying heat waves of Iran and their characteristic such as duration, frequency and severity, to this end maximum daily temperature data of 663 synoptic and climatology stations since 23/1/1961to 19/3/2004(15701 day) were used. Then by using Kriging interpolation method with 18*18 km pixels, we produced a matrix with 15705*7187 dimensions that the days located on the row and pixels on the columns. At the next stage by using Fumiyaki index, the matrix was standardized and normal temperature deviation of Iran was formed. For identifying heat waves of Iran by using computer programming in Matlab Software the heat waves was defined as the days with a continues heat of at least two days and its temperature is +2 of standard deviation or more than average (NTD).After performing program on NTD matrix of Iran.we identified and classified 282 heat waves 2 -25 days...
These heat waves from the lowest duration of 2days up to most pervasive duration of 25days were classified and analyzed in warm and cold periods. Finally this research showed that short waves have more events and the long heat wave have least events.
The heat waves are more at the end of winter and the first days of autumn.This time is simultaneous with the change of cold period to warm and warm to cold. The long heat waves were least event but they covered more areas of Iran and the short heat waves were more event but they covered minimum areas of Iran. The heat wave are more event in north and northwest, central of Iran and south coastal areas. Also warm waves had increasing trend and have had more events at recent years.