Ayat Rohina - Postgraduate in watershed management engineering, Payam Noor University part-time instructor, DehDasht branch, Kohkiloie Va Boirahmad, Iran
Mohammad Karami - Postgraduate in watershed management engineering, Islamic azad university of Arsanjan branch, Arsanjan, Fars, Iran
Ayob Bahranifard - Postgraduate in watershed management engineering, Islamic azad university of Arsanjan branch, Arsanjan, Fars, Iran
Mohsen Dehghan - Postgraduate in watershed management engineering, Islamic azad university of Arsanjan branch, Arsanjan, Fars, Iran

Sensitivity analysis to determine variations in evapotranspiration is much important considering a known variation in one of climatic variables. In this study, sensitivity of evapotranspiration from Penmann-Mantith, Penmann-Kimberly (۱۹۹۶), Penman-Kimberly (۱۹۷۲) and Penmann (۱۹۸۴)  and Hargrivs (۱۹۸۵) approaches to three climatic variations (maximum temperature, wind speed, solar radiation) was studied in station Fasa for an interval of ۲۲ years (۱۹۸۲-۲۰۰۳). In this research, in order to represent the effect of climatic variables on evapotranspiration, variation percentage standard was used. The results showed that, in most approaches, the most sensitivity was to net radiation, maximum temperature and wind speed, respectively. The results of this study are applicable for measurement of climatic variations in order to estimate evapotranspiration.

Potential evapotranspiration, Sensitivity analysis, Variation coefficient, Fasa synoptic station