A study on temporal variation of weather parameters in North East of Iran (Case study on North khorasan and Razavi Khorasan provinces)

In this paper we study on trend and variation in climatic parameters in North east of Iran. Calculation and analysis on rainfall and humidity on the average of minimum and maximum temperature parameters have been performed over the period of 1986 to 2005. The selected stations are Mashhad, Bojnourd, Quchan, Sabzevar, Sarakhs and Torbat Heydarie. The Mann-Kendall has been used to illustrate trends of this parameters. Minimum and maximum temperatures at all stations show an increasing trend. This results show that the temperature has remarkable change in winter than other seasons. Therefore, this will effect on rainfall pattern which will lead gradually to change on flow pattern and ultimately impact on water resources management of region. Rainfall and humidity does not show a clear trend. The results show that if this trend persists, Extreme conditions maybe change and increased flooding and droughts in this region.