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Assessment of Spatial and Temporal Variability of Extreme Precipitation Indices (North and West of Iran)
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Mojtaba Nassaji Zavareh *   , Bagher Ghermezcheshmeh |
| Education and Extension Organization (AREEO), Tehran, Iran |
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Abstract: (1454 Views) |
The frequency of precipitation extreme event can cause flood or change the drought period. Accurate understanding of these changes is necessary to take action to reduce these effects. In this research, temporal and spatial changes of 14 precipitation indices for eight synoptic stations in the North and West of the country were investigated. For this purpose, after reconstructing the daily precipitation indices defined by ETCCDI were evaluated using RClimdex software. To evaluate heavy precipitation, indices of very wet days, extremely wet days, number of days with precipitation of more than 10, 20, and 25 mm and distribution of the top 60, 40, and 20 daily precipitations were evaluated. The result showed that the trend indices of extremely wet days (R99p) and 20, 40, and 60 precipitation events in Rasht, Ramsar, Bandar Anzali and Khoramabad stations were positive and it was negative at the other stations. Total precipitation index (PRCPTOT) in all stations expect Babolsar had a negative and significant trend. The trend of simple daily intensity, Max. 1-day precipitation and Max. 5-day precipitation indices in the most stations in the North and West of the country were positive and insignificant. The trend of the number of consecutive dry days (CDD) in all stations in the North of the country was positive, which indicates increase in the length of the dry season. Also, the number of consecutive wet (CWD) in the western part the country had a negative trend, which indicates a decrease in the number of wet days. The result of this study showed that precipitation indices in a climatic zone have a spatial discontinuity and the behavior of precipitation is towards extreme value. |
Article number: 3 |
| Keywords: Climate change, Extreme precipitation indices, North and West Iran, Trend. |
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Full-Text [PDF 1431 kb]
(188 Downloads)
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Type of Study: Research |
Subject:
Special
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