Analyzing the Geostatistical Methods Accuracy in Preparing Air Temperature Spatial Distribution in Mountainous Regions (Case Study: Karoun Basin)

The lack of enough meteorological stations at high elevations in mountainous regions causes a limitation for using regression relations to interpolate air temperatures at different time scales. Therefore, in this study, geostatistical methods include Kriging, Co-Kriging and Weighting moving average has been compared with elevation-temperature relation using a data series of 25 years (1975-2000). Evaluating the selected interpolation methods has been done based on Root Mean Square Error, Mean Absolute Error and Mean Biass Error. Also the physical conception of estimated values has been analyzed based on extracted maps. Results showed that using elevation as a covariate in Cokriging method caused a 28% increase in effective range. Although Kriging method overestimate the monthly and yearly air temperature, no significant difference was observed in evaluating indices between Kriging and Cokriging methods. Results also demonstrated that both Kriging and Cokriging method could be used instead of linear regression to interpolate air temperature in the study area. Analyzing prepared maps showed a decreasing pattern in air temperature from east to west parts.