Investigation of Changes in the Amount and Distribution of Precipitation and Temperature in Iran and Their Effects on Extreme Events
Global warming in recent decades has caused significant changes in precipitation and temperature, including changes in the mean and standard deviation of these variables and changes in the intensity and frequency of climatic extremes (floods and droughts). Given the importance of these changes in wa...
| Main Authors: | , |
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| Format: | Article |
| Language: | fas |
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Ferdowsi University of Mashhad
2023-08-01
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| Series: | آب و توسعه پایدار |
| Subjects: | |
| Online Access: | https://jwsd.um.ac.ir/article_44370_736b891a3e268ab3109f739c2f65b3bc.pdf |
| Summary: | Global warming in recent decades has caused significant changes in precipitation and temperature, including changes in the mean and standard deviation of these variables and changes in the intensity and frequency of climatic extremes (floods and droughts). Given the importance of these changes in water resources management, it is crucial to study the trends in these variables. In this study, in 12 selected stations in different climatic regions in Iran, the changes in monthly and annual precipitation and mean temperature during 1961-1990 and 1991-2020 were examined. The results of Mann-Kendall test showed in most stations precipitation had an increasing trend in the first period, and a decreasing trend in the second period; although in both periods the trend was not significant (Z<1.645). The mean temperature has increased in both periods, which in the second period has increased with a higher level of confidence (Z>2,576) and greater slope than in the first period. The average annual rainfall has decreased in most stations, and the average annual temperature has increased in all stations. The distribution of precipitation and temperature showed that in some stations, the probability of occurrence of extreme events and hot and cold periods in the second period has increased compared to the first period. In some other stations, droughts/floods are more/less likely to occur. This indicates that the activity of air masses affecting each station can be intensified or weakened due to climate change. |
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| ISSN: | 2423-5474 2717-3321 |