Description of Spatial Structure of Annual Precipitation of Iran

Due to deep، complex and everlasting interaction between precipitation and climatic elements-factors، there are changes and varieties in both time and space dimensions. So that climate experts and related scientists take their attentions to this phenomenon. An approach to do this kind of investigations is to describe spatial variations based on spatial statistics. In this paper the main object is to introduce principles of spatial statistics as well as describing general behaviors of Iran precipitation along the space. Accordingly daily precipitation of 1437 synoptic، climatology and rain gage stations during 1961/3/21 to 2004/12/31has been used. First of all the Kriging technique has been used to investigate precipitation distribution. In the next step three characters including spatial distribution، spatial correlation and regression models have been done. The results show that central mean has occurred at 34º 41` N and 50º 58`E. the spatial variation in central mean is occurred in path of the main systems that bring the precipitation to Iran. Spatial correlation shows 12 KM distance for significant correlation. The best fitted model shows slop and its direction the most affective spatial factors on precipitation.