Analysis and Prediction of Monthly and Annual Rainfall in Mashad Catchment Area during 2005

In this paper the total amount of monthly and annual rainfall in Mashad city has been analyzed. The historical rainfall in this basin in the period of January 1984 till August 2004 has been collected from the annual published Iranian meteorological Organization. This paper contains three parts in which in the first section the monthly rainfall has been analyzed and in the second section the annual rainfall has been considered. For the purpose of analysis of the data and their forecasts, the exponential smoothing method and Box and Jenkins method has been used and the forecasts of the remaining 4 months of the year 2004 and the first 6 months of 2005 and the total amount of annual rainfall in the years 2005, 2006 and 2007. In the third section the analysis of mean annual temperature and its effects on total amount of annual rainfall has been considered by regression method and the conclusion leads towards the inverse and meaningful relation between these two variables, since the forecasts values of the mean annual temperature in the years of 2005 till 2007 has been done by this method which shows a positive trend.