Comparative Study of Multi-Day Intense Precipitations over Iran

Comparative Study of Multi-Day Intense Precipitations over Iran

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Part of #Comparative Study of Multi-Day Intense Precipitations over Iran# :

Publishing year : 2005

Conference : The first Iranian-Korean joint workshop on climate modeling

Number of pages : 14

Abstract: Precipitation is one of the meteorological variables that have the highest spatial and temporal variability. There is increasing attention to variations and trends of extreme values of such a variable in local, regional and global scales. Extreme events of precipitation have had a serious effect on human lives and properties. In this paper, we examine extreme precipiations in view of monthly maximum 1-day (Rxlday) and monthly maximum sequential 5-day (RxSday) precipitations over those Iranian synoptic stations with reliable data. These indices can also be determined seasonally, but seasonal indices are more spatially coherent than the annual indices, and spatial coverage remains globally poor. We mainly worked on 16 Synoptic stations that are distributed well over the country. Highest 1 day and 5 days precipitations among the stations under study are 353 mm from Bandar Anzali on September 17th, 1962 and 487 mm from Ramsar respectively 2-6 October 1993. Lowest
Those are 41 mm from Bam on January 26, 1991 and 5 1 mm from the same city on 20-24 January of 1957. We got negative trends for Rx5day in NW, West of Zagros mountain range, Caspian Sea coastal area, NE, SE and some stations located in the south of Iran. We did not
Find a clear pattern for Rxlday over the country. Whole country actually showed a mixed pattern. We also received significant negative trends for this index for Shiraz and Zahedan, and a significant positive trend for Abadan at 0.05 significant levels.