Potential Evapotranspiration is one of important hydrological cycle elements that is Considered in water resources, Irrigation water constructions and agricultural problemp.
Amount of air temperature range and its annual regine assessment is very important in arid regions. Since Precipitation is low in this area, Temperature and its variation affect directly on evapotranspirational Phenomena and water requirement in different months and Sease.
This research has used meteoeological data stations (Ghasr-Ghand, Pirsohrab, Kajdar Sarbaz, Pishin, Kahir, Tis and Bahouklat). Then for determing the best method has been done Comparasion by diagrametic analysis. Based on estimations have been gained the following results: The Southern Balouchestan area regarding ‘existence Water and temperature” it is Possible Farming activities all year. In This regard two Potential evapotranspiration methods such as Bleny-criddle and thornth-waite has been Calwlated Whole year. Thornth-wait method does not represent correct results for season but Bleny-criddle has a good correlation to Pan. Also it is decreased the amount of evaporation from west and north toward west and south. The amount of potential evapotranspiration is higher than, precipitation all the year.
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