Skip to Main Content

The estimation of total PMF-56 ET0 obtained from the estimated ET0 values was also considered for comparison due to its importance in water balance calculation, water resources planning and management. The total estimated ET0 amounts in testing periods are given in Table 5, showing that most models underestimated total PMF-56 ET0 value. The GA-SVM8, SVM8, and ANN8 models, whose input parameters were Tmin, Tmax, U2, RH, and Rs, estimated the total PMF-56 ET0 value of 551.19 mm as 538.96 mm, 537.94 mm, and 536.54 mm, with an underestimation of 2.22%, 2.40%, and 2.66%, respectively. The total PMF-56 ET0 amount estimates of the GA-SVM8 and SVM8 were closer to the PMF-56 ET0 values. Among the models, the GA-SVM8 model had the best estimate (−2.22%) and the SVM8 had the second best estimate (−2.40%).

Table 5

Total ET0 values and relative error calculated by various models during the testing periods

GA-SVM
SVM
ANN
InputTotal ET0.(mm)Relative error (%)Total ET0.(mm)Relative error (%)Total ET0.(mm)Relative error (%)
507.64 −7.90 502.39 −8.85 486.14 −11.80 
519.51 −5.75 517.90 −6.04 495.39 −10.12 
529.13 −4.00 528.85 −4.05 524.70 −4.81 
509.35 −7.59 520.98 −5.48 516.94 −6.21 
521.64 −5.36 520.88 −5.50 504.69 −8.44 
528.21 −4.17 528.35 −4.14 513.22 −6.89 
533.74 −3.17 535.93 −2.77 525.42 −4.68 
538.96 −2.22 537.94 −2.40 536.54 −2.66 
GA-SVM
SVM
ANN
InputTotal ET0.(mm)Relative error (%)Total ET0.(mm)Relative error (%)Total ET0.(mm)Relative error (%)
507.64 −7.90 502.39 −8.85 486.14 −11.80 
519.51 −5.75 517.90 −6.04 495.39 −10.12 
529.13 −4.00 528.85 −4.05 524.70 −4.81 
509.35 −7.59 520.98 −5.48 516.94 −6.21 
521.64 −5.36 520.88 −5.50 504.69 −8.44 
528.21 −4.17 528.35 −4.14 513.22 −6.89 
533.74 −3.17 535.93 −2.77 525.42 −4.68 
538.96 −2.22 537.94 −2.40 536.54 −2.66 

Close Modal

or Create an Account

Close Modal
Close Modal