Choosing the Best Method of Interpolation for the Average Zoning of Annual Temperature in Iran

The present study was done through Iran to investigate the best method of spatial interpolation to estimate the annual average temperature. Therefore, the data of 180 synoptic stations in Iran were used. Using different interpolation methods (IDW, GPI, LPI and RBF) with different powers of 1, 2, 3, 4 and 5 and models (Completely Regularized Spline, Inverse Multi-quadric, Multi-quadric, Spline with Tension, and Thin Plate Spline), spatial distribution of the average annual precipitation was investigated to recognize the best method of interpolation. The geo-statistical interpolation methods were kriging and co-kriging. Using some evaluation methods and some indices (RMSE, MBE, MAPE and R), the best method for interpolation was selected. Finally, annual temperature map in GIS was provided by the best method. The results showed that the RBF method has the least RMSE and the most correlation relationship than the others for the interpolating the annual average temperature in Iran (Multi-quadric)