بررسي و تحليل نوسانات بارش برف سنگين در شمال غرب ايران

Analysis and review of heavy snow fluctuations in North West of Iran

In order to review changes to heavy snow in northwestern Iran, daily temperature and rainfall data in 10 synoptic stations, were obtained Iran Metrological center. Statistical analysis and in all stations showed heavy snow in the region with large fluctuations and also its reduction, especially in recent decades. Downtrend in receiving heavy snow for Tabriz and Urmia stations using the rank test MAN- Kendall revealed, but in Ardebil and Khoy such process was not observed. Change and sudden decrease in precipitation and heavy snow, Particularly in Ardebil and Urmia stations are other findings of this study although this change was not significant. Furthermore, review shows that heavy snow in Ardebil, Ahar and Khalkhal stations for few months are more frequently happened than in other stations, so that Ardebil keeps records by receiving 90% of total rainfall as heavy snow in 5 months (Nov. to Mar.).