Analysis of the trend of temperature indices in Khuzestan province (period 1996-2020)

Climate change increases the probability of the occurrence of extreme phenomena, which have large social and environmental effects on a regional and local scale. Climate changes resulting from global warming have had many effects on Khuzestan province over the past few decades. The purpose of this research is to determine and examine the annual trend of extreme temperature indices (warm days, cool days, warm nights, cool nights, heat wave length index) in meteorological stations of Khuzestan province during the period of 1996-2020.For this purpose, the minimum and maximum daily temperature data of the selected meteorological stations of Khuzestan province was extracted and using statistical relationships such as trend line equations, trend line coefficient and Mann-Kendall test (to determine significance), the trend of temperature indices was investigated. The results showed negative trend changes in the indicators of cool days and cool nights, positive trend changes in the indicators of warm days, warm nights and heat wave length index in the studied stations. Also, the Mann-Kendall test showed the significance of the observed trends for the index of warm days (at the stations of Izeh, Mahshahr, Behbahan, Dezful, Ramhormoz, Shushtar and Abadan), index of cool days (at the stations of Omidiyeh, Masjid Sulaiman, Abadan, Ahvaz , Izeh, Behbahan, Ramhormoz, Shushtar, Mahshahr and Bostan), warm nights index (in Abadan, Omidiyeh, Ahvaz, Bostan and Mahshahr stations) and heat wave length index (in Izeh and Mahshahr stations). But the index of cool nights had no significant trend in all stations.