Investigation of temporal-spatial distribution of Diurnal Temperature Range in Fars province

Diurnal Temperature Range (DTR) is an important indicator for identifying climate change. The purpose of this study is to analyze the seasonal and annual trends of the Diurnal Temperature Range and their changes during the 20-year statistical period from 2001/03/21 to 2021/03/20 in Fars province. For this purpose, monthly minimum and maximum temperature data, which are the most important parameters related to climate change and affect ecological activities in 26 stations of the province were obtained from the Meteorological Organization. Among the stations in the province, only 13 stations had a statistical length of more than 20 years, which was selected for review and comparison for this study due to the common period, and the desired index was calculated for the selected stations. After performing the thigh homogeneity test on the data, Mann-Kendall statistical and graphical test was used to determine the trend and the sens slop Estimator Nonparametric Method was used to determine the trend slope rate. The highest trend rates and changes in time were observed in summer and the lowest in autumn. In estimating the sens slope to determine the direction of the index trend, it was revealed that some stations have experienced incremental changes of more than 2 degrees Celsius. Maps of trend type and amount of changes were also drawn. Examination of the maps showed that the western half of the province has experienced an increasing trend and the highest rate of change can be seen in the same area.