Applicability Analysis of Calculation Methods for ET_0 with Limited Weather Data in Wuhan

The reference crop evapotranspiration of each typical hydrological year in Wuhan is calculated by Priestley-Taylor formula,Hargreaves formula and Penman-Monteith formula.Based on the results of Penman-Monteith formula,the outcomes of Priestley-Taylor formula and Hargreaves formula are analyzed.It shows that there is no significant difference between the results of Hargreaves formula and those of Penman-Monteith formula.When the weather data required by Penman-Monteith formula is unavailable in this district,Hargreaves formula can be used to calculate ET0 instead of Penman-Monteith formula.There are many differences between the results of Priestley-Taylor formula and those of Penman-Monteith formula,Priestley-Taylor formula needs modifying when used to calculate ET0 instead of Penman-Monteith formula in this district.