Detection of Climate Fluctuations Based on the Mann-Whitney Test (Case Study: Ahvaz)

One of the concerns of the human society is that the changes caused by global warming change the frequency and amount of precipitation and temperature. This study was conducted to investigate the trend of annual, seasons of cultivation, seasonal and monthly temperature and precipitation changes using the Mann-Whitney test at Ahvaz Meteorological Station. The study period consisted of two 31-year periods from 1957 to 2018. The results of this study showed that the minimum temperature had more changes compared to the average and maximum temperatures in the first 31 years (1957-1987) compared to the second 31 years (1988 to 2018). Mean comparison of minimum temperature and average temperature for the two periods showed that there was a significant difference at the 5% of probability level.  The means of the minimum and average temperature increased from 12.1 to 14.9 and 24.9 to 26.9°C, respectively. Mean comparison of the maximum temperature and precipitation for the two periods showed that there was no significant difference at the 5% of probability level. The averages of the maximum temperature and precipitation decreased from 37.5 to 36.8°C and 226.9 to 188.8 mm, respectively. Also, the study of precipitation trend in the two studied periods showed a high distribution of this climate parameter and a small change in the amount of this factor.