The reduction of rainfall, lack of water resources and inappropriate use of surface and underground water resources are the main limitations for agricultural developments. To have sustainable agriculture and to develop more agricultural lands, water resources should be managed properly. Evapotrairation is the key factor influence water resources management. For irrigation projects, to reduce water losses and to increase water use efficiency, it is necessary to determine crop water requirements. The crop water requirements depend on potential ET, and therefore it is necessary to determine the potential ET for each area. In this study, the AHP method was used for mapping the potential evapotrairation for selected stations of Fars Province, in Iran. First, the potential ET’s were calculated based on Penmam-Montith and Hargereaves-Samani, methods using REF ET software. Then, the monthly and yearly mappings of the potential evapotrairations were done for Fars Province. The parameters affecting ET are latitude, wind speed, relative humidity, day time hours, temperature and precipitation. Using EXPERT CHOICE software, each pairs of these parameters was compared and analyzed for selected stations. Then, based on the effects that each parameter has on ET, these parameters were Keywords: GIS Mapping, Potential ET, Climatic data, AHP, Fars Province
