A Preview of Iran's Climate Using SIAP Method

Climate and its related parameters such as precipitation, temperature, moisture, and so on, and also their probable changes during a certain period play a major role in human living environment. Therefore, through the recognition of these elements and the relevant changes using quantitative and statistical models, there will be provided the possibility of sustainable utility of the nature.In the existing study, we have used the precipitation records of synoptic stations of Iran for a long term period, after retrieving the data and applying homogeneity tests. Using the SIAP equation, we have drawn zoning map of Iran based on standardized values and the coefficient of variation of precipitation have been studied and finally the coefficients of variation map of Iran has been prepared. According to the results obtained, in the years 1966 and 1973 all over Iran has experienced droughts and since 1995 until 2001 a very long desiccation in most parts of Iran has dominated. Also the studies indicate that the relationship between height and precipitation in Iran has a high rate of uniformity and the study should be carried out in a regional basis, because there is no correlation between precipitation and height in some parts of Iran. For example, the Caspian Sea shores experience higher amounts of precipitation despite their lower elevation, and can be regarded as one of the precipitation poles of Iran. The reason is that the rainfalls in Caspian shorelines are generally derived from convective and dynamic rising rather than orography. The effective factor in Iran's precipitation in winters is the emergence of western air masses and the existence of subtropical Azure high pressure, and in summer the dominance of dry periods.