Comparison of General Circulation Models: methodology for selecting the best GCM in Kermanshah Synoptic Station, Iran

General Circulation Models (GCMs) suggest that rising concentrations of greenhouse gases will have significant implications for climate at global and regional scales. Increased concentration of greenhouse gases in the atmosphere leads to change in air temperature and precipitation. Temperature and precipitation are important parameters for water management, so the climate change studies on different systems such as climatology and water resources can lead to more optimal water resource management and planning. In this research, correlation and frequency analysis is used for uncertainty analysis, then Hadley Centre Coupled Model version3 (HadCM3) is selected as the best GCM for Kermanshah synoptic station, Iran.