Table 10 Average statistical indicators values for different standalone and hybrid ML models across studied stations during testing phase with various input combinations.

From: Comparative assessment of empirical and hybrid machine learning models for estimating daily reference evapotranspiration in sub-humid and semi-arid climates

Model

Inputs combination

Gharb

Loukkos

KGE

R2

RMSE

RRSE

Rank

KGE

R2

RMSE

RRSE

Rank

RF1

Tmax, Tmin, Rs

0.882

0.841

0.026

18.807

29

0.953

0.952

0.034

9.593

28

RF2

Tmax, Tmin, RHmean

0.762

0.652

0.068

29.891

46

0.730

0.612

0.098

27.187

46

RF3

Tmax, Tmin, Rs, U2

0.913

0.945

0.021

12.211

15

0.942

0.961

0.031

8.682

17

RF4

Tmax, Tmin, RHmean, U2

0.832

0.801

0.054

20.591

38

0.786

0.723

0.082

22.947

36

RF5

Tmax, Tmin, RHmean, Rs

0.912

0.913

0.025

14.936

22

0.938

0.958

0.033

9.093

22

RF6

Tmax, Tmin, RHmean, Rs, U2

0.919

0.966

0.020

10.066

7

0.933

0.966

0.030

8.296

13

M5P1

Tmax, Tmin, Rs

0.731

0.797

0.041

24.662

40

0.920

0.941

0.042

11.536

32

M5P2

Tmax, Tmin, RHmean

0.629

0.635

0.074

35.360

48

0.557

0.610

0.108

30.175

48

M5P3

Tmax, Tmin, Rs, U2

0.927

0.911

0.024

14.801

21

0.951

0.952

0.035

9.650

29

M5P4

Tmax, Tmin, RHmean, U2

0.808

0.779

0.058

22.586

39

0.721

0.697

0.086

24.067

39

M5P5

Tmax, Tmin, RHmean, Rs

0.889

0.916

0.024

15.739

24

0.931

0.952

0.036

9.999

31

M5P6

Tmax, Tmin, RHmean, Rs, U2

0.933

0.955

0.022

11.272

12

0.960

0.958

0.032

8.939

20

XGBoost1

Tmax, Tmin, Rs

0.900

0.833

0.027

19.749

34

0.966

0.948

0.036

9.978

30

XGBoost2

Tmax, Tmin, RHmean

0.769

0.632

0.070

31.163

47

0.732

0.585

0.102

28.406

47

XGBoost3

Tmax, Tmin, Rs, U2

0.969

0.950

0.019

11.361

13

0.978

0.964

0.029

8.204

12

XGBoost4

Tmax, Tmin, RHmean, U2

0.873

0.801

0.054

19.976

36

0.807

0.691

0.088

24.405

40

XGBoost5

Tmax, Tmin, RHmean, Rs

0.945

0.907

0.024

15.214

23

0.966

0.957

0.033

9.047

21

XGBoost6

Tmax, Tmin, RHmean, Rs, U2

0.982

0.975

0.017

8.253

4

0.977

0.969

0.027

7.630

5

LightGBM1

Tmax, Tmin, Rs

0.892

0.842

0.026

18.668

28

0.969

0.954

0.034

9.418

25

LightGBM2

Tmax, Tmin, RHmean

0.772

0.661

0.067

29.437

43

0.739

0.616

0.097

27.097

45

LightGBM3

Tmax, Tmin, Rs, U2

0.967

0.950

0.019

11.248

11

0.980

0.968

0.028

7.774

9

LightGBM4

Tmax, Tmin, RHmean, U2

0.864

0.812

0.053

19.561

33

0.806

0.718

0.083

23.171

38

LightGBM5

Tmax, Tmin, RHmean, Rs

0.944

0.918

0.023

14.212

18

0.973

0.964

0.030

8.337

15

LightGBM6

Tmax, Tmin, RHmean, Rs, U2

0.975

0.977

0.016

7.916

3

0.982

0.973

0.026

7.134

3

RF-M5P1

Tmax, Tmin, Rs

0.843

0.846

0.027

18.928

30

0.944

0.955

0.034

9.447

26

RF-M5P2

Tmax, Tmin, RHmean

0.734

0.669

0.067

29.657

44

0.687

0.631

0.096

26.724

41

RF-M5P3

Tmax, Tmin, Rs, U2

0.915

0.948

0.019

11.851

14

0.943

0.964

0.030

8.349

14

RF-M5P4

Tmax, Tmin, RHmean, U2

0.825

0.811

0.053

20.097

37

0.766

0.735

0.081

22.509

33

RF-M5P5

Tmax, Tmin, RHmean, Rs

0.907

0.922

0.023

14.258

19

0.936

0.962

0.031

8.759

19

RF-M5P6

Tmax, Tmin, RHmean, Rs, U2

0.920

0.973

0.018

9.211

6

0.940

0.970

0.028

7.755

8

RF-LightGBM1

Tmax, Tmin, Rs

0.890

0.847

0.025

18.302

25

0.967

0.956

0.033

9.218

23

RF-LightGBM2

Tmax, Tmin, RHmean

0.770

0.666

0.067

29.207

41

0.738

0.625

0.096

26.747

42

RF-LightGBM3

Tmax, Tmin, Rs, U2

0.956

0.954

0.018

10.830

8

0.971

0.969

0.027

7.635

6

RF-LightGBM4

Tmax, Tmin, RHmean, U2

0.855

0.815

0.052

19.425

32

0.801

0.727

0.082

22.766

34

RF-LightGBM5

Tmax, Tmin, RHmean, Rs

0.936

0.921

0.022

13.939

16

0.964

0.965

0.029

8.179

11

RF-LightGBM6

Tmax, Tmin, RHmean, Rs, U2

0.960

0.978

0.015

7.813

2

0.968

0.975

0.025

6.925

1

RF-XGBoost1

Tmax, Tmin, Rs

0.890

0.844

0.025

18.570

27

0.958

0.953

0.034

9.459

27

RF-XGBoost2

Tmax, Tmin, RHmean

0.767

0.656

0.067

29.759

45

0.733

0.615

0.097

27.089

44

RF-XGBoost3

Tmax, Tmin, Rs, U2

0.931

0.953

0.019

11.216

10

0.954

0.965

0.029

8.157

10

RF-XGBoost4

Tmax, Tmin, RHmean, U2

0.845

0.809

0.053

19.832

35

0.794

0.725

0.082

22.855

35

RF-XGBoost5

Tmax, Tmin, RHmean, Rs

0.924

0.917

0.023

14.461

20

0.946

0.961

0.031

8.746

18

RF-XGBoost6

Tmax, Tmin, RHmean, Rs, U2

0.938

0.974

0.017

8.685

5

0.946

0.971

0.027

7.619

4

XGBoost-LightGBM1

Tmax, Tmin, Rs

0.898

0.847

0.025

18.418

26

0.970

0.955

0.034

9.342

24

XGBoost-LightGBM2

Tmax, Tmin, RHmean

0.774

0.663

0.067

29.418

42

0.739

0.618

0.097

27.020

43

XGBoost-LightGBM3

Tmax, Tmin, Rs, U2

0.968

0.954

0.018

10.831

9

0.980

0.969

0.028

7.686

7

XGBoost-LightGBM4

Tmax, Tmin, RHmean, U2

0.867

0.816

0.052

19.188

31

0.808

0.720

0.083

23.083

37

XGBoost-LightGBM5

Tmax, Tmin, RHmean, Rs

0.946

0.918

0.022

14.131

17

0.971

0.963

0.030

8.351

16

XGBoost-LightGBM6

Tmax, Tmin, RHmean, Rs, U2

0.977

0.979

0.015

7.598

1

0.981

0.974

0.025

7.038

2

  1. Significant values are in bold.
  2. Significant values are in bold underline.