Evapotranspiration is the combination of soil evaporation and crop transpiration. Evapotranspiration is the part of the water cycle and critical parameter for the water management and planning. Considering increasing population of earth, evapotranspiration becomes more important. The aim of this study is to calculate the reference evapotranspiration (ET0) by using FAO Penman-Monteith and Turc method at Kars station located in northeastern of Turkey. Monthly minimum temperature, monthly maximum temperature, monthly average dewpoint temperature, monthly minimum relative humidity, monthly maximum relative humidity, monthly average relative humidity, monthly average wind speed, monthly average solar radiation and sunshine duration were used as data for the period 2014-2017. ET0 values seen in all months for two different methods are tabulated. Avarage ET0 values obtained from Turc and FAO Penman-Monteith methods are charted. The highest ET0 for Penman method was seen in September 2017 (9.7 mm/day) while the highest ET0 for Turc method was seen in July 2017 (4.8 mm/day) compared to years 2014, 2015 and 2016. Discrepancies between two methods are charted to see the changes of ET0 It is concluded that ET0 values obtained from temperature-based Turc method are lower than FAO Penman-Monteith values by reason of Kars province is located in the coldest part of Turkey.
Anahtar Kelimeler: FAO Penman-Monteith, Turc Method, Evapotranspiration