Investigation of Distribution Spatial Distribution by Final Interpolation Methods and Statistical Grounds (Case Study: Isfahan Province)

The spatial variations of rainfall are due to differences and climatic variations, and to produce spatial variation maps and regional average estimates, it is necessary to interpolate the amount of precipitation between stations. In the present research, geostatistical and deterministic interpolation methods were developed for the spatial distribution map of the annual rainfall in Isfahan province. The data of 20 meteorological stations of Isfahan province were used during the period 1987 to 2017. Results show higher accuracy of geostatistical interpolation method. From this, the cokriging method has the most precision with the exponential model and the auxiliary variable of the station's height. According to the spatial distribution map of annual rainfall, which was prepared by the cokriging method, the highest mean annual rainfall (Pt) was found in south and west of Isfahan province. The lowest rainfall in the east and north of Isfahan province is due to the presence of dry plains and climates.